Download Topic 1 Quantitative Chemistry File

Quantitative Chemistry
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Definitions
Avogadro’s constant: The number of particles in 12g of 12C.
Concentration: the amount of solute per unit of volume of solution
Formula, empirical: The formula obtained by experiment, showing the simplest whole number
ratio of atoms of each element in a particle of a substance.
Formula, molecular: The formula showing the actual number of atoms of each element in a
particle of a substance.
Formula, structural: Shows the arrangement of atoms and bonds within a molecule.
Ideal gas: A gas for which the relationship pV = nRT holds true.
Limiting reagent: The reactant which will determine the theoretical maximum amount of
product formed.
Maxwell-Boltzmann distribution: Graph showing the distribution of kinetic energies among
molecules.
Molar mass: The mass of a mole of a substance.
Molar volume: At 273 K and 1 atm (STP), one mole of any gas will occupy 22.4 dm3.
Mole: The amount of substance that contains a number of specified species equal to Avogadro‟s
constant.
Solute: A substance that is dissolved into another (the solvent)
Solvent: a substance that dissolves another (the solute)
Yield, percentage: The experimental yield as a percentage of the maximum theoretical yield
(experimental/theoretical*100)
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The Mole Concept
1. One mole of water contains
A 6.02 × 1023 atoms of hydrogen.
B 2.01 × 1023 atoms of oxygen.
C 6.02 × 1023 atoms in total.
D 6.02 × 1023 molecules of water.
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2. The number of atoms present in 36 molecules of glucose (C6H12O6) is
A 24
B 36
C 24 × 36
D 24 × 36 × 6.02 × 10236.
3. The mass of one atom of carbon -12 is:
A 1 g.
B 12 g.
C 12 × 6.02 × 1023 g.
D 12 / 6.02 × 1023 g.
4. A sample of phosphoric(V) acid H3PO4 contains 1.2 × 1023 molecules.
(a) Calculate how many moles of phosphoric(V) acid is this.
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(b) Calculate how many atoms of phosphorus will there be.
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(c) Calculate how many atoms of hydrogen will it contain.
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5.
(a) Calculate how many molecules are there in 6 moles of hydrogen sulfide (H2S).
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(b) The formula of gold(III) chloride is AuCl3. Calculate how many chloride ions are
there in 0.30 moles of gold(III) chloride.
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Molar Mass Practice Worksheet
Find the molar masses of the following compounds:
Remember that if you don‟t use units in your answer, the answer is wrong!
1)
NaBr
2)
PbSO4
3)
Ca(OH)2
4)
Na3PO4
5)
(NH4)2CO3
6)
C6H12O6
7)
Fe3(PO4)2
8)
(NH4)2S
9)
Zn(C2H3O2)2
10)
AgF
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Moles and Molar Mass
1) Find the molar mass for the following compounds:
a) Ethanoic acid, C2H4O2 (60.05 g/mol)
b) Ammonium Sulphate, (NH4)2SO4 (132.13 g/mol)
c) Nicotine, C10N2H14 (162.23 g/mol)
2) Convert to mass in grams.
a) 5.0 moles molecular oxygen O2 (159.9 g)
b) 5.0 mole ammonia, NH3 (85.2g)
c) 5.0 mole glucose, C6H12O6 (900.8g)
d) 1 molecule of water, H2O (2.99 x 10-23 g)
e) 1.00 x 10+22 molecules of acetic acid C2H4O2 (0.997 g)
3) Convert to moles.
a) 1.0 g sodium chloride, NaCl (0.017 mol)
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b) 1.0 g of water H2O (0.056 mol)
c) 1.0 g of glucose, C6H12O6 (0.0056 mol)
d) 1 molecule of carbon dioxide, CO2 (1.66 x 10-24 mol)
e) 3.01 x 10+23 formula units of potassium iodide, KI (0.500 mol)
f) 6.02 x 10+24 molecules of camphor (10.0 mol)
4) Convert to molecules.
a) 1.00 g of propane, C3H8 (1.37 x 1022 molecules)
b) 2.0 moles of morphine, C17O3NH22 (1.2 x 1024 molecules)
5) A sample of C2H4O contains 40.2 g of C. How many moles of compound are present? (1.67 mol)
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6) A sample of C4H6N2O2 has a mass of 257 g. How many moles of H does it contain? (13.5 mol)
7) Glucose molecules have the formula C6H12O6.
a) How many glucose molecules are there in one mole of glucose? (6.02 x 1023 molecules)
b) How many carbon atoms are in one molecule of glucose? (6 carbon atoms)
c) How many carbon atoms in one mole of glucose? (3.61x 1024 carbon atoms)
d) How many moles of hydrogen in one mole of glucose? (12 mol)
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Molar Mass Worksheet Extra Practice
Calculate the molar masses of the following chemicals:
1)
Cl2
2)
KOH
3)
BeCl2
4)
FeCl3
5)
BF3
6)
CCl2F2
7)
Mg(OH)2
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8)
UF6
9)
SO2
10)
H3PO4
11)
(NH4)2SO4
12)
CH3COOH
13)
Pb(NO3)2
14)
Ga2(SO3)3
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Mole Calculation Worksheet
1)
How many moles are in 15 grams of lithium?
2)
How many grams are in 2.4 moles of sulfur?
3)
How many moles are in 22 grams of argon?
4)
How many grams are in 88.1 moles of magnesium?
5)
How many moles are in 2.3 grams of phosphorus?
6)
How many grams are in 11.9 moles of chromium?
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7)
How many moles are in 9.8 grams of calcium?
8)
How many grams are in 238 moles of arsenic?
What are the molecular weights of the following compounds?
9)
NaOH
12)
H3PO4
10)
H2O
13)
Mn2Se7
11)
MgCl2
14)
(NH4)2SO4
15)
How many grams are in 4.5 moles of sodium fluoride, NaF?
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16)
How many moles are in 98.3 grams of aluminum hydroxide, Al(OH)3?
17)
How many grams are in 0.02 moles of beryllium iodide, BeI2?
18)
How many moles are in 68 grams of copper (II) hydroxide, Cu(OH)2?
19)
How many grams are in 3.3 moles of potassium sulfide, K2S?
20)
How many moles are in 1.2 x 103 grams of ammonia, NH3?
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21)
How many grams are in 2.3 x 10-4 moles of calcium phosphate, Ca3(PO3)2?
22)
How many moles are in 3.4 x 10-7 grams of silicon dioxide, SiO2?
23)
How many grams are in 1.11 moles of manganese sulfate, Mn3(SO4)7?
Moles, Molecules, and Grams Worksheet
1)
How many molecules are there in 24 grams of FeF3?
2)
How many molecules are there in 450 grams of Na2SO4?
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3)
How many grams are there in 2.3 x 1024 atoms of silver?
4)
How many grams are there in 7.4 x 1023 molecules of AgNO3?
5)
How many grams are there in 7.5 x 1023 molecules of H2SO4?
6)
How many molecules are there in 122 grams of Cu(NO3)2?
7)
How many grams are there in 9.4 x 1025 molecules of H2?
8)
How many molecules are there in 230 grams of CoCl2?
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9)
How many molecules are there in 2.3 grams of NH4SO2?
10)
How many grams are there in 3.3 x 1023 molecules of N2I6?
11)
How many molecules are there in 200 grams of CCl4?
12)
How many grams are there in 1 x 1024 molecules of BCl3?
13)
How many grams are there in 4.5 x 1022 molecules of Ba(NO2)2?
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14)
How many molecules are there in 9.34 grams of LiCl?
15)
How many grams do 4.3 x 1021 molecules of UF6 weigh?
16)
How many molecules are there in 230 grams of NH4OH?
Grams/Moles Calculations
Given the following, find the number of moles:
1)
30 grams of H3PO4
2)
25 grams of HF
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3)
110 grams of NaHCO3
4)
1.1 grams of FeCl3
5)
987 grams of Ra(OH)2
6)
564 grams of copper
7)
12.3 grams of CO2
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8)
89 grams of Pb(CH3COO)4
Given the following, find the number of grams:
9)
4 moles of Cu(CN)2
10)
5.6 moles of C6H6
11)
21.3 moles of BaCO3
12)
1.2 moles of (NH4)3PO3
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13)
9.3 x 10-3 moles of SmO
14)
6.6 moles of ZnO
15)
5.4 moles of K2SO4
16)
88.4 moles of NI3
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Mole Problem
Using your knowledge of mole calculations and unit conversions, determine how many atoms
there are in 1 gallon of gasoline. Assume that the molecular formula for gasoline is C6H14
and that the density of gasoline is approximately 0.85 grams/mL.
There are _______________________________ atoms in 1 gallon of gasoline.
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EMPIRICAL FORMULA WORKSHEET
1. What is the empirical formula for a compound which contains 0.0134
g of iron, 0.00769 g of sulfur and 0.0115 g of oxygen?
2. Find the empirical formula for a compound which contains 32.8%
chromium and 67.2% chlorine.
3. NAME the compound which contains 0.463 g Tl (#81), 0.0544 g of
carbon, 0.00685 g of hydrogen and 0.0725 g oxygen by finding its
empirical formula.
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4. What is the empirical formula for a compound which contains 67.1%
zinc and the rest is oxygen?
5. Barry Um has a sample of a compound which weighs 200 grams and
contains only carbon, hydrogen, oxygen and nitrogen. By analysis, he
finds that it contains 97.56 grams ofcarbon, 4.878 g of hydrogen,
52.03 g of oxygen and 45.53 g of nitrogen. Find its empirical formula.
6. The characteristic odor of pineapple is due to ethyl butyrate, an
organic compound which contains only carbon, hydrogen and oxygen. If
a sample of ethyl butyrate is known to contain 0.62069 g of carbon,
0.103448 g of hydrogen and 0.275862 g of oxygen, what is the
empirical formula for ethyl butyrate?
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7. 300 grams of a compound which contains only carbon, hydrogen and
oxygen is analyzed and found to contain the exact same percentage of
carbon as it has oxygen. The percentage of hydrogen is known to be
5.98823%. Find the empirical formula of the compound.
8. 200.00 grams of an organic compound is known to contain 83.884
grams of carbon, 10.486 grams of hydrogen, 18.640 grams of oxygen
and the rest is nitrogen. What is the empirical formula of the
compound?
9. 300 grams of an organic sample which contains only carbon,
hydrogen and oxygen is analyzed and found to contain 145.946 grams
of carbon, 24.3243 grams of hydrogen and the rest is oxygen. What is
the empirical formula for the compound?
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Percent Composition and Molecular Formula
Worksheet
1)
What‟s the empirical formula of a molecule containing 65.5% carbon, 5.5%
hydrogen, and 29.0% oxygen?
2)
If the molar mass of the compound in problem 1 is 110 grams/mole, what‟s
the molecular formula?
3)
What‟s the empirical formula of a molecule containing 18.7% lithium, 16.3%
carbon, and 65.0% oxygen?
4)
If the molar mass of the compound in problem 3 is 73.8 grams/mole, what‟s
the molecular formula?
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Empirical Formula and Molecular Formula
1. Eugenol is the active component of oil of cloves. It has a molar
mass of 164.2 g/mol and is 73.14% C and 7.37% H; the remainder
is oxygen. What is the empirical and the molecular formulas for
eugenol? C5H6O & C10H12O2
2. Isoprene is a volatile, fragrant liquid that polymerizes to form
natural rubber. It has 88.17% carbon and 11.83% hydrogen. Its
molar mass is 68.11 g/mol. What are its empirical and molecular
formulas? C5H8
3. Propylene glycol has been suggested as an alternative to ethylene
glycol which is used as antifreeze. Ethylene glycol istoxic but
propylene glycol is not. Propylene glycol has 47.35% C and 10.60%
H with the remainder being O. If the molar mass is 76.10 g/mol,
what are the empirical and molecular formulas of propylene
glycol? C3H8O2
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4. Analysis shows that 0.586 g of potassium can combine with 0.480 g
of O2 gas to give a white solid with a formula of KxOy.
What is the formula of the white solid? KO2
5. Several samples of an unknown substance were analyzed. The results
revealed that only the elements iron and oxygen were
present. The data for 2 of the samples are summarized below.
Sample 1
Sample 2
Mass of sample
7.32 g
9.55 g
Mass of iron
5.69 g
6.68 g
Mass of oxygen
1.63 g
2.87 g
Are these samples the same substance? Explain.
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Formulas
1. The molar mass of iron(III) sulfate Fe2(SO4)3 will be
A 191.76 g mol–1
B 207.76 g mol–1
C 344.03 g mol–1
D 399.88 g mol–1
2.
A certain substance has a molar mass (to 2 significant figures) of 28 g mol–1.
Which of the following is not a possible formula?
A CH2O
B Si
C C2H4
D CO
3. Calculate the molar mass of the following substances (correct to 1 decimal place).
(a) HI
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(b) NaClO3
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(c) (NH4)2HPO4
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(d) (CO2H)2.2H2O
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(e) Chromium(III) oxide
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(f) Iodine trichloride
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Moles and mass
4. One drop of water weighs 0.040 g. Calculate how many molecules are there in one
drop, taking the molar mass of water as exactly 18 g.mol-1.
A 1.3 × 1021
B 2.4 × 1022
C 3.3 × 1022
D 3.9 × 1022
5.
Determine the mass (in g) of one molecule of sulfuric acid (H2SO4).
A 98.08
B 98.08 ÷ (6.02 × 1023)
C 98.08 ÷ 7
D 98.08 ÷ (7 × 6.02 × 1023)
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6. A polymer molecule has a mass of 2.5 × 10-20 g. Determine the molar mass of the
polymer.
A 1.4 × 104 g mol-1
B 2.4 × 1043 g mol-1
C 6.7 × 10-5 g mol-1
D 4.2 × 10-44 g mol-1
7. Calculate (correct to 3 significant figures) the mass of
(a) 3.00 moles of ammonia.
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(b) ¼ mole of Li2O.
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(c) 0.0500 moles of aluminium nitrate.
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(d) 3.01 × 1023 molecules of PCl3.
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(e) 2.60 × 1022 molecules of dinitrogen monoxide.
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8.
Calculate how many moles are there in
(a) 28.1 g of silicon.
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(b) 303 g of KNO3.
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(c) 4000 g of nickel sulfate.
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(d) 87.3 g of methane.
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9.
a) 0.30 moles of a substance has a mass of 45 g. Determine its molar mass.
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b) 3.01 × 1025 molecules of a gas has a mass of 6.40 kg. Determine its molar mass.
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10. Some types of freon are used as the propellant in spray cans of paint, hair spray,
and other consumer products. However, the use of freons is being curtailed,
because there is some suspicion that they may cause environmental damage. If
there are 25.00 g of the freon CCl2F2 in a spray can, calculate how many molecules
are you releasing to the air when you empty the can.
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11. Vitamin C, ascorbic acid, has the formula C6H8O6.
a) The recommended daily dose of vitamin C is 60.0 milligrams. Calculate how many
moles are you consuming if you ingest 60 milligrams of the vitamin.
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b) A typical tablet contains 1.00 g of vitamin C. Calculate how many moles of vitamin
C does this represents.
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c) When you consume 1.00 g of vitamin C, calculate how many oxygen atoms are you
eating.
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Percentage composition and empirical formula
12. A certain compound has a molar mass of about 56 g mol–1. All the following are
possible empirical formulas for this compound except
A CH2
B CH2O
C C3H4O
D CH2N
13. The empirical formula of a compound with the molecular formula C6H12O3 is
A C6H12O3
B C3H6O2
C C2H3O
D C2H4O
14. What percentage by mass of sodium thiosulfate pentahydrate (Na2S2O3•5H2O) is
water.
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15. a) 2.0 g of an oxide of iron contains approximately 0.60 g oxygen and 1.4 g iron.
Determine the empirical formula of the oxide.
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b) A compound of silicon and fluorine contains about 73% fluorine by mass.
Determine its empirical formula.
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c) A compound of carbon, hydrogen and oxygen only, with a molar mass of ≈90 g mol1
contains 26.6% carbon and 2.2% hydrogen by mass. Determine its molecular
formula.
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16. 1.000 g of tin metal burns in air to give 1.270 g of tin oxide. Determine the
empirical formula of the oxide.
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17. A 1.39 g sample of hydrated copper(II) sulfate (CuSO4•xH2O) is heated until all the
water of hydration is driven of. The anhydrous salt has a mass of 0.89 g. Determine
the formula of the hydrate.
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18. The red colour of blood is due to haemoglobin. It contains 0.335% by mass of iron.
Four atoms of iron are present in each molecule of haemoglobin. If the molar mass
of iron is 55.84 g mol–1, estimate the molar mass of haemoglobin.
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19. A 200.0 mg sample of a compound containing potassium, chromium, and oxygen was
analyzed and found to contain 70.8 mg chromium and 53.2 mg potassium. Calculate
the empirical formula of the sample.
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20. The molecular formula of the insecticide DDT is C14H9Cl5. Calculate the molar mass
of the compound and the percent by mass of each element.
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21. The percentages of carbon, hydrogen, and oxygen in vitamin C are determined by
burning a sample of vitamin C weighing 1.000 g. The masses of CO2 and H2O formed
are 1.500 g and 0.408 g, respectively.
a) Calculate the masses and amounts of carbon and hydrogen in the sample.
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b) Determine the amount of oxygen in the sample.
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c) From the above data, determine the empirical formula of vitamin C.
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22. The percentages by mass of carbon, hydrogen and nitrogen in an unknown compound
are found to be 23.30%, 4.85%, and 40.78%, respectively. (Why do. these not add
up to 100%?). Determine the empirical formula of the compound. If the molar mass
of the compound is 206 g mol-1, determine its molecular formula.
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Efflorescence is the process by which some hydrated salts lose water of crystallisation
when exposed to the air. „Washing soda‟ (Na2CO3•10H2O) is converted to the monohydrate
(Na2CO3•H2O) when exposed to the air. Determine the percentage loss in mass of the
crystals.
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Making Flash Cards
Cut out the cards
Write the Chemical Symbol on one side of the card and the name on the other side.
Use these to help you to memorise these compounds and polyatomic ions.

Sulfuric acid
H2SO4

Sulphate
SO42-

Nitric acid
HNO3

Nitrate
NO3-

Ammonia
NH3

Phosphate
PO43-

Hydrochloric acid HCl

Carbonate
CO32-

Ethanoic acid

Hydroxide
OH-

Carbon monoxide CO

Hydrogen Carbonate HCO3-

Sulfur dioxide

Permanganate
CH3COOH
SO2
MnO
Nitrate
Phosphate
Carbonate
Hydroxide
Hydrogen
Carbonate
Permanganate
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Sulphuric Acid
Nitric Acid
Ammonia
Hydrochloric Acid
Ethanoic Acid
Carbon Monoxide
Sulphur Dioxide
Sulphate
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Word Equations
Write the word equations below as chemical equations and balance:
1)
Zinc and lead (II) nitrate react to form zinc nitrate and lead.
_________________________________________________________
2)
Aluminum bromide and chlorine gas react to form aluminum chloride and bromine gas.
_________________________________________________________
3)
Sodium phosphate and calcium chloride react to form calcium phosphate and sodium
chloride.
_________________________________________________________
4)
Potassium metal and chlorine gas combine to form potassium chloride.
_________________________________________________________
5)
Aluminum and hydrochloric acid react to form aluminum chloride and hydrogen gas.
_________________________________________________________
6)
Calcium hydroxide and phosphoric acid react to form calcium phosphate and water.
_________________________________________________________
7)
Copper and sulfuric acid react to form copper (II) sulfate and water and sulfur dioxide.
_________________________________________________________
8)
Hydrogen gas and nitrogen monoxide react to form water and nitrogen gas.
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Topic 1.3 Formulas
1. Write the formulas of the following common compounds:
a) Sulfuric acid……………………………………………..
b) Sodium hydroxide……………………………………………..
c) Nitric acid……………………………………………..
d) Ammonia……………………………………………..
e) Hydrochloric acid ……………………………………………..
f) Ethanoic acid……………………………………………..
g) Copper (II) sulfate……………………………………………..
h) Carbon monoxide……………………………………………..
i) Sulfur dioxide ……………………………………………..
j) Sodium hydrogencarbonate……………………………………………..
2.
Write the formulas of the following substances:
a) Sodium chloride……………………………………………..
b) Copper (II) sulfide……………………………………………..
c) Zinc sulfate ……………………………………………..
d) Aluminium oxide……………………………………………..
e) Magnesium nitrate……………………………………………..
f) Calcium phosphate……………………………………………..
g) Hydroiodic acid……………………………………………..
h) Ammonium carbonate……………………………………………..
i) Methane ……………………………………………..
j) Phosphorus pentachloride……………………………………………..
3. Insert coefficients, to balance the following equations.
(a) ………. CaO +………. HNO3  ………. Ca(NO3)2 +………. H2O
(b) ………. NH3 + ………. H2SO4  ………. (NH4)2SO4
(c) ………. HCl + ………. ZnCO3  ………. ZnCl2 + ………. H2O + ………. CO2
(d) ………. SO2 +………. Mg  ………. S +………. MgO
(e) ………. Fe3O4 + ………. H2  ………. Fe + ………. H2O
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(f) ………. K + ………. C2H5OH  ………. KC2H5O + ………. H2
(g) ………. Fe(OH)3 ……….  Fe2O3 + ………. H2O
(h) ………. CH3CO2H + ………. O2  ………. CO2 + ………. H2O
(i) ………. Pb(NO3)2 ……….  PbO + ………. NO2 + ………. O2
(j) ………. NaMnO4 + ………. HCl  ………. NaCl + ………. MnCl2 + ………. Cl2 + ………. H2O
5. Write balanced equations for the following reactions.
(a) Copper(II) carbonate forming copper (II) oxide and carbon dioxide.
………………………………………………………………………………………………………………………………………………………………….
(b) Nickel oxide reacting with sulfuric acid to form nickel sulfate and water.
………………………………………………………………………………………………………………………………………………………………….
(c) Iron and bromine reacting to give iron(III) bromide.
………………………………………………………………………………………………………………………………………………………………….
(d) Lead(IV) oxide and carbon monoxide forming lead metal and carbon dioxide.
………………………………………………………………………………………………………………………………………………………………….
(e) Iron(II) chloride reacting with chlorine to form iron(III) chloride.
………………………………………………………………………………………………………………………………………………………………….
(f) Ethanol burning in air to form carbon dioxide and water.
………………………………………………………………………………………………………………………………………………………………….
(g) Silver reacting with nitric acid to form silver nitrate, nitrogen dioxide and water.
………………………………………………………………………………………………………………………………………………………………….
(h) Manganese(IV) oxide reacting with hydrochloric acid to form manganese(II) chloride, chlorine
and water.
………………………………………………………………………………………………………………………………………………………………….
(i) Sulfur dioxide reacting with hydrogen sulfide to form sulfur and water.
………………………………………………………………………………………………………………………………………………………………….
(j) Ammonia reacting with oxygen to form nitrogen monoxide and water.
………………………………………………………………………………………………………………………………………………………………….
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Balancing Chemical Equations
Balance the equations below:
1)
2)
____ N2 + ____ H2  ____ NH3
____ KClO3  ____ KCl + ____ O2
3)
____ NaCl + ____ F2  ____ NaF + ____ Cl2
4)
____ H2 + ____ O2  ____ H2O
5)
____ Pb(OH)2 + ____ HCl  ____ H2O + ____ PbCl2
6)
____ AlBr3 + ____ K2SO4  ____ KBr + ____ Al2(SO4)3
7)
____ CH4 + ____ O2  ____ CO2 + ____ H2O
8)
____ C3H8 + ____ O2  ____ CO2 + ____ H2O
9)
____ C8H18 + ____ O2  ____ CO2 + ____ H2O
10)
____ FeCl3 + ____ NaOH  ____ Fe(OH)3 + ____NaCl
11)
____ P + ____O2  ____P2O5
12)
____ Na + ____ H2O  ____ NaOH + ____H2
13)
____ Ag2O  ____ Ag + ____O2
14)
____ S8 + ____O2  ____ SO3
15)
____ CO2 + ____ H2O  ____ C6H12O6 + ____O2
16)
____ K + ____ MgBr  ____ KBr + ____ Mg
17)
____ HCl + ____ CaCO3  ____ CaCl2 + ____H2O + ____ CO2
18)
____ HNO3 + ____ NaHCO3  ____ NaNO3 + ____ H2O + ____ CO2
19)
____ H2O + ____ O2  ____ H2O2
20)
____ NaBr + ____ CaF2  ____ NaF + ____ CaBr2
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21)
____ H2SO4 + ____ NaNO2  ____ HNO2 + ____ Na2SO4
Six Types of Chemical Reaction Worksheet
Balance the following reactions and indicate which of the six types of chemical reaction are being
represented:
1)
____ NaBr + ____ Ca(OH)2  ___ CaBr2 + ____ NaOH
Type of reaction: _____________________________
2)
____ NH3+ ____ H2SO4  ____ (NH4)2SO4
Type of reaction: _____________________________
3)
____ C5H9O + ____ O2  ____ CO2 + ____ H2O
Type of reaction: _____________________________
4)
____ Pb + ____ H3PO4  ____ H2 + ____ Pb3(PO4)2
Type of reaction: _____________________________
5)
____ Li3N + ____ NH4NO3  ___ LiNO3 + ___ (NH4)3N
Type of reaction: _____________________________
6)
____ HBr + ___ Al(OH)3  ___ H2O + ___ AlBr3
Type of reaction: _____________________________
7)
What‟s the main difference between a double displacement reaction and an acid-base reaction?
8)
Combustion reactions always result in the formation of water. What other types of chemical
reaction may result in the formation of water? Write examples of these reactions on the
opposite side of this paper.
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A Voyage through Equations
After working on this worksheet, you should be able to do the following:
1)
Given an equation, you should be able to tell what kind of reaction it is.
2)
Predict the products of a reaction when given the reactants.
Section 1: Identify the type of reaction
For the following reactions, indicate whether the following are examples of synthesis, decomposition,
combustion, single displacement, double displacement, or acid-base reactions:
1)
Na3PO4 + 3 KOH  3 NaOH + K3PO4 _________________________
2)
MgCl2 + Li2CO3  MgCO3 + 2 LiCl _________________________
3)
C6H12 + 9 O2  6 CO2 + 6 H2O _________________________
4)
Pb + FeSO4  PbSO4 + Fe _________________________
5)
CaCO3  CaO + CO2 _________________________
6)
P4 + 3 O2  2 P2O3 _________________________
7)
2 RbNO3 + BeF2  Be(NO3)2 + 2 RbF ________________________
8)
2 AgNO3 + Cu  Cu(NO3)2 + 2 Ag ________________________
9)
C3H6O + 4 O2  3 CO2 + 3 H2O _________________________
10)
2 C5H5 + Fe  Fe(C5H5)2 _________________________
11)
SeCl6 + O2  SeO2 + 3Cl2 _________________________
12)
2 MgI2 + Mn(SO3)2  2 MgSO3 + MnI4 _________________________
13)
O3  O. + O2 _________________________
14)
2 NO2  2 O2 + N2_________________________
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Section 2: Practicing equation balancing
Before you can write a balanced equation for a problem which asks you to predict the products of a
reaction, you need to know how to balance an equation. Because some of you may not fully remember how
to balance an equation, here are some practice problems:
1)
__ C6H6 + __ O2  __ H2O + __ CO2
2)
__ NaI + __ Pb(SO4)2  __ PbI4 + __ Na2SO4
3)
__ NH3 + __ O2 __ NO + __ H2O
4)
__ Fe(OH)3  __ Fe2O3 + __ H2O
5)
__ HNO3 + __ Mg(OH)2  __H2O + __ Mg(NO3)2
6)
__ H3PO4 + __ NaBr  __ HBr + __ Na3PO4
7)
__ C + __ H2  __ C3H8
8)
__ CaO + __ MnI4  __ MnO2 + __ CaI2
9)
__ Fe2O3 + __ H2O  __ Fe(OH)3
10)
__ C2H2 + __ H2  __ C2H6
11)
__ VF5 + __ HI  __ V2I10 + __ HF
12)
__ OsO4 + __ PtCl4  __ PtO2 + __ OsCl8
13)
__ CF4 + __ Br2  __ CBr4 + __ F2
14)
__ Hg2I2 + __ O2  __ Hg2O + __ I2
15)
__ Y(NO3)2 + __ GaPO4  __ YPO4 + __ Ga(NO3)2
Section 3: Predicting the products of chemical reactions
Predict the products of the following reactions:
1)
__ Ag + __CuSO4 
Type:___________________________
2)
__ NaI + __ CaCl2 
Type:___________________________
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3)
__ O2 + __ H2 
Type:___________________________
4)
__ HNO3 + __ Mn(OH)2 
Type:___________________________
5)
__ AgNO2 + __ BaSO4 
Type:___________________________
6)
__ HCN + __ CuSO4 
Type:___________________________
7)
__ H2O + __ AgI 
Type:___________________________
8)
__ HNO3 + __Fe(OH)3 
Type:___________________________
9)
__ LiBr + __ Co(SO3)2 
Type:___________________________
10)
__ LiNO3 + __Ag 
Type:___________________________
11)
__ N2 + __ O2 
Type:___________________________
12)
__ H2CO3 
Type:___________________________
13)
__ AlCl3 + __ Cs 
Type:___________________________
14)
__ Al(NO3)3 + __ Ga 
Type:___________________________
15)
__ H2SO4 + __ NH4OH 
Type:___________________________
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16)
__ CH3COOH + __ O2 
Type:___________________________
17)
__ C4H8 + __ O2 
Type:___________________________
18)
__ KCl + __ Mg(OH)2 
Type:___________________________
19)
__ Zn + __ Au(NO2)2 
Type:___________________________
20)
__ KOH + __ H2SO4 
Type:___________________________
21)
__ BaS + __ PtCl2 
Type:___________________________
22)
__ Na2O 
Type:___________________________
Writing Complete Equations Practice
For each of the following problems, write complete chemical equations to describe the chemical process
taking place. Important note: There are a few physical processes on this sheet – remember, you can‟t
write an equation for a physical process!
1)
When lithium hydroxide pellets are added to a solution of sulfuric acid, lithium sulfate and water
are formed.
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2)
When dirty water is boiled for purification purposes, the temperature is brought up to 1000 C for
15 minutes.
3)
If a copper coil is placed into a solution of silver nitrate, silver crystals form on the surface of
the copper. Additionally, highly soluble copper (I) nitrate is generated.
4)
When crystalline C6H12O6 is burned in oxygen, carbon dioxide and water vapor are formed.
5)
When a chunk of palladium metal is ground into a very fine powder and heated to drive off any
atmospheric moisture, the resulting powder is an excellent catalyst for chemical reactions.
Reaction Products Worksheet
For each of the following reactions, determine what the products of each reaction will be. When you
have predicted the products, balance the equation and use a table of solubility products to determine
which of the products (if any) will precipitate. Assume all reactions take place in water.
1)
____ Ca(OH)2 + ____ HF 
2)
____ Pb(NO3)2 + ____ K2CrO4 
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3)
____ NaC2H3O2 + ____ H2SO4 
4)
____ Cu(OH)2 + ____ H3PO4 
5)
____ AgNO3 + ____ Na2CO3 
6)
____ Zn + ____ H2CO3 
7)
____ Pb(OH)2 + ____ Hg2S 
Double Displacement Reactions
Indicate which of the following double displacement reactions will go to completion, and circle
what the product of the reaction will be (if any). You may want to consult a list of Ksp values to
solve these problems.
1)
___ NaOH + ___ CaBr2 
Will this reaction occur? _____
2)
___ Pb(NO3)2 + ___ HCl 
Will this reaction occur? _____
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3)
___ Na2CO3 + ___ KF 
Will this reaction occur? _____
4)
___ AgNO3 + ___ CuSO4 
Will this reaction occur? _____
5)
___ AgF + ___ NiCl2 
Will this reaction occur? _____
6) Devise a method for making silver chromate, given any two other ionic compounds. Write the
equation here:
7) On the next page, indicate how much of each reagent you would require to make 100 grams of
silver chromate.
Kinetic Molecular Theory of Gases Worksheet
1) Name the postulates of the kinetic molecular theory and state whether or
not you believe they do a good job of describing how real gases behave.
2) Based on the postulates of the kinetic molecular theory, give the
conditions of pressure and temperature that you believe would cause a
real gas to best simulate an ideal gas. Explain your answer.
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3) Avogadro‟s Law states that the volume of a gas is directly proportional to
the number of moles of gas, but has nothing to do with the identity of the
gas. Is this law correct for an ideal gas? Explain.
4) Nowadays, we have a much better idea of how gases behave than when
the gas laws were first invented. Explain why we continue to use these
laws even though we can get better answers with the information we have
today.
Stoichiometry 2
For each of the following problems the correct chemical formulas for each substance and a
complete, balanced equation must be written before you can do any calculations.
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1) Predict the number of moles of ammonium hydroxide required to produce 0.13 mol of
iron(III) hydroxide.
(0.39 mol)
ammonium hydroxide + iron(III) nitrate  ammonium nitrate + iron(III) hydroxide
2) How many moles of ammonium chloride would be required for an exact reaction with 420
mol of calcium hydroxide (slaked lime) ?
(840 mol)
ammonium chloride + calcium hydroxide
ammonium hydroxide + calcium chloride
3) Ammonia, NH3 , for the production of fertilizers may be produced by the reaction of
hydrogen with nitrogen obtained from air. Predict the number of moles of hydrogen gas
required to react with excess nitrogen to prepare 0.602 mol of ammonia. (0.903 mol)
4) Sodium reacts with water to produce sodium hydroxide and hydrogen gas. How many grams
of sodium are needed to produce 1 mol of hydrogen gas? (46 g)
5) Calculate the number of grams of hydrogen which must be burned with oxygen to form
60.0 grams of water.
(6.7 g)
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6) How many grams of SbCl3 would have to react with hydrogen sulfide to produce 34 grams of
Sb2S3 (along with one other product)?
(45.6 g)
7) How many grams of zinc must be treated with sulfuric acid in order to liberate 5.0 grams of
hydrogen gas (along with one other product)? (163.5 g)
8) If 149 grams of Phosphorus, P4 , was burned in oxygen to produce the only product, P4O10 ,
how many moles of this only product would be produced?
(1.2)
Limiting Reagent Worksheet
Using your knowledge of stoichiometry and limiting reagents, answer the following questions:
1)
Write the balanced equation for the reaction of lead (II) nitrate with sodium iodide to form
sodium nitrate and lead (II) iodide:
2)
If I start with 25.0 grams of lead (II) nitrate and 15.0 grams of sodium iodide, how many grams
of sodium nitrate can be forme
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3)
What is the limiting reagent in the reaction described in problem 2?
4)
How much of the nonlimiting reagent will be left over from the reaction in problem #2?
Mass to Mass Stoichiometry Problems
In the following problems, calculate how much of the indicated product is made. Show all your work.
1)
LiOH + HBr  LiBr + H2O
If you start with ten grams of lithium hydroxide, how many grams of lithium bromide will be
produced?
2)
C2H4 + 3 O2  2 CO2 + 2 H2O
If you start with 45 grams of ethylene (C2H4), how many grams of carbon dioxide will be
produced?
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3)
Mg + 2 NaF  MgF2 + 2 Na
If you start with 5.5 grams of lithium chloride, how many grams of calcium chloride will be
produced?
4)
2 HCl + Na2SO4  2 NaCl + H2SO4
If you start with 20 grams of hydrochloric acid, how many grams of sulfuric acid will be
produced?
Limiting Reagents & Percent Yield Calculations – 1
1) Write the balanced chemical equation.
2) Calculate the number of moles of each reagent.
3) Use the molar ratios from the balanced chemical equation to determine the
limiting reagent.
4) Use the limiting reagent to calculate the moles of the excess reagent needed to
react with the limiting reagent. To determine the amount in excess of the
other reactant, subtract the needed moles from the actual moles.
5) To find percent yield, find the theoretical yield (from molar calculations).
1. Given 182.0g of lead(II) nitrate & 263.0g of potassium iodide, what is the limiting
reagent?
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How much are you in excess of the other reactant?
If you recover 192.3g of lead(II) iodide, what is your percent yield?
2. 8.51 g H2 and 9.25 g of O2, in the reaction: 2H2 + O2 →2H2O What is the limiting
reagent?
How much are you in excess of the other reactant?
3. 1.00 mole of Ca and 1.00 mole of Cl2 were present as reactants. Only 106 g of CaCl2 is
produced. What is the percent yield?
Ca + Cl2 →CaCl2
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Limiting Reagent & Percent Yield Calculations - 2
A substance that is not present in sufficient quantities to react with all of another substance is called a limiting
reagent; the other substance is said to be in excess.
For each of the following reactants, determine which substance is the limiting reagent. Also, calculate the amount
by which the other substance is in excess.
Limiting Reagent
1) 8.51 g H2 and 9.25 g of O2, in the reaction 2H2 + O2 ➔ 2H2O
Limiting reagent: _______________
Amount by which other reactant is in excess _______________
2) 0.143g of K and 0.236 g Cl2 , in the reaction 2K + Cl2 ➔ 2KCl
Limiting reagent: _______________
Amount by which other reactant is in excess _______________
3) 7.45 g N2 and 4.20 g O2, in the reaction 2N2 + O2 ➔ 2N2O
Limiting reagent: _______________
Amount by which other reactant is in excess _______________
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4) Assume that 2.40 moles of oxygen are reacted with 2.46 moles of magnesium to produce
magnesium oxide, MgO. Determine which reactant is in excess and by what amount, and
calculate the number of moles of product formed.
Excess reagent: _______________
Amount in excess _______________
Moles formed: _______________
5) Assume that 13.1 g of potassium are reacted with 18.0 g of oxygen to produce potassium
oxide. Determine which reactant is in excess and by what amount, in moles, and calculate the
number of grams of products formed.
Excess reagent: _______________
Amount in excess _______________
Grams formed: _______________
Percent Yield
Actual yield divided by the ideal, or theoretical yield, and multiplied by 100 equals percent yield. Calculate percent
yield for the following reactions.
1) 1.00 mole of Ca and 1.00 mole of Cl2 were present as reactants. Only 106 g of CaCl2
ismproduced. What is the percent yield? Ca + Cl2 ➔ CaCl2
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Percent Yield: _______________
2) 0.60 mole of N2 and 1.80 mole of H2 were present as reactants. Only 14.5 g of NH3 arem
produced. What is the percent yield?
N2 + 3H2 ➔2NH3
Percent Yield: _______________
3) When 21.8 g of silver nitrate, AgNO3, are reacted with an excess of sodium chloride, 17.8 g
of silver chloride, AgCl, are formed. Calculate the percent yield of silver chloride.
Percent Yield: _______________
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Limiting Reagents Calculations – 3
1. Wine turns into vinegar when the ethanol in the wine, C2H5OH, reacts with oxygen to form
acetic acid, CH3CO2H.
C2H5OH(aq) + O2 (g)  CH3CO2H(aq) + H2O(l)
Suppose 1.12 g of oxygen were sealed in a wine bottle that contains 2.28 g of ethanol. Which
reactant is limiting, oxygen or ethanol? Explain. Oxygen
2. Sulfur dioxide gas reacts with hydrogen sulfide gas, producing solid sulfur and water vapor.
8 SO2(g) + 16 H2S(g)  3 S8(s) + 16 H2O(g)
Suppose 32.4 g of SO2 are combined with 28.7 g of H2S. Which reactant is limiting and which
is in excess? How many grams of sulfur can be produced? How many grams of the excess
reactant remain when the reaction is complete? H2S is limiting; SO2 in excess
40.5g S produced; 5.4 g SO2 remain
3. The combustion of N2 gas yields the pollutant NO2. Calculate the percent yield of NO2 if
16.0 grams of NO2 form when 56 g of nitrogen gas burn? 8.6%
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4. The reaction between SO2(g) and molecular oxygen yields SO3(g). Calculate the percent
yield of SO3 if 40 grams of SO3 form when 32 grams of SO2 react with an excess of oxygen.
100%
5. In the reaction of 4.0 moles of N2 with 6.0 moles of H2, 1.6 moles of NH3 were obtained.
What is the percent yield?
40
Percent, Actual, and Theoretical Yield
1)
LiOH + KCl  LiCl + KOH
a) I began this reaction with 20 grams of lithium hydroxide. What is my theoretical yield of
lithium chloride?
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b) I actually produced 6 grams of lithium chloride. What is my percent yield?
2)
C3H8 + 5 O2  3 CO2 + 4 H2O
a) If I start with 5 grams of C3H8, what is my theoretical yield of water?
b) I got a percent yield of 75% How many grams of water did I make?
3)
Be + 2 HCl  BeCl2 + H2
My theoretical yield of beryllium chloride was 10.7 grams. If my actual yield was 4.5 grams, what
was my percent yield?
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4)
2 NaCl + CaO  CaCl2 + Na2O
What is my theoretical yield of sodium oxide if I start with 20 grams of calcium oxide?
5)
FeBr2 + 2 KCl  FeCl2 + 2 KBr
a) What is my theoretical yield of iron (II) chloride if I start with 34 grams of iron (II)
bromide?
b) What is my percent yield of iron (II) chloride if my actual yield is 4 grams?
6)
TiS + H2O  H2S + TiO
What is my percent yield of titanium (II) oxide if I start with 20 grams of titanium (II) sulfide
and my actual yield of titanium (II) oxide is 22 grams?
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7)
U + 3 Br2  UBr6
What is my actual yield of uranium hexabromide if I start with 100 grams of uranium and get a
percent yield of 83% ?
8)
H2SO4  H2O + SO3
If I start with 89 grams of sulfuric acid and produce 7.1 grams of water, what is my percent
yield?
Molar Gas Volume
Since 1 mole of any gas at STP will always have a volume of 22.4 l, gas math is easy.
Assume STP for all questions.
1. Fill in the blanks:
Gas
Number of moles
(mol.)
Number of
Particles
CO2
1
6.0 x 10
23
CO
1
6.0 x 10
23
6.0 x 10
20
O2
Volume of Gas (L)
O3
2241
----------
2.241
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2. a) 0.0224 L of SO2 is produced in a reaction. How many moles?
b) 10. mol. of CO2 take sup what volume?
c) True/False: 11200ml of gas takes up 2.00 mol. of any gas at STP?
3.
mass(g)
Mmass(g/mol)
=
Volume(L)
22.4(L/mol)
a) What elemental gas has a mass of 8.0g and takes up 44.8 L at STP?
b) Does butane (C4H10) or butene (C4H8) occupy 2240 ml and have a mass of 5.8g?
c) Does the following data support the hypothesis that the gas is hydrogen cyanide?
A mass of 2.7 x 103 g occupies a volume of 22400l at STP.
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4)
MolarMass(g/mol)
Gas density =
molar volume (L)
=
Volume(L)
22.4(L/mol)
a) What is the density of CO2 at STP?
b) What is the density of CO at STP?
c) What is the density of phosphorous trihydride at STP?
d) What noble gas has a density of 5.84 x 10-3g/ml at STP?
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Ideal Gas Law Problems
Use the ideal gas law to solve the following problems:
1)
If I have 4 moles of a gas at a pressure of 5.6 atm and a volume of 12 liters, what is the
temperature?
2)
If I have an unknown quantity of gas at a pressure of 1.2 atm, a volume of 31 liters, and a
temperature of 87 0C, how many moles of gas do I have?
3)
If I contain 3 moles of gas in a container with a volume of 60 liters and at a temperature of 400
K, what is the pressure inside the container?
4)
If I have 7.7 moles of gas at a pressure of 0.09 atm and at a temperature of 56 0C, what is the
volume of the container that the gas is in?
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5)
If I have 17 moles of gas at a temperature of 67 0C, and a volume of 88.89 liters, what is the
pressure of the gas?
6)
If I have an unknown quantity of gas at a pressure of 0.5 atm, a volume of 25 liters, and a
temperature of 300 K, how many moles of gas do I have?
7)
If I have 21 moles of gas held at a pressure of 78 atm and a temperature of 900 K, what is the
volume of the gas?
8)
If I have 1.9 moles of gas held at a pressure of 5 atm and in a container with a volume of 50
liters, what is the temperature of the gas?
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9)
If I have 2.4 moles of gas held at a temperature of 97 0C and in a container with a volume of 45
liters, what is the pressure of the gas?
10)
If I have an unknown quantity of gas held at a temperature of 1195 K in a container with a volume
of 25 liters and a pressure of 560 atm, how many moles of gas do I have?
11)
If I have 0.275 moles of gas at a temperature of 75 K and a pressure of 1.75 atmospheres, what
is the volume of the gas?
12)
If I have 72 liters of gas held at a pressure of 3.4 atm and a temperature of 225 K, how many
moles of gas do I have?
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Ideal Gas Law Problems-1
Ideal Gas Law:
PV = nRT
R = 8.314 J/K mol
82.06 cm3 atm/mol K
0.08206 L atm/mol K
62.4 L torr/mol K
Problem Type 1: - given all variables except 1
What is the volume of 1.00 mol of gas at STP? (ans: 22.4 L)
Problem Type 2: - condition 1 to condition 2
A helium weather balloon resting near the ground at a pressure of 754 mm Hg and a
temperature of 22.5 °C, has a volume of 4.19 x 103 L. What will be the new volume at a height
20 miles from the Earth‟s surface where the temperature is -33.0°C and the pressure is 76.0
mm Hg. ans: 33761 L
Problem Type 3: - involving density and molar mass
The density of a gas at STP is 1.23 g/L. Calculate its molar mass. ans: 27.6 g/mol
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Problem Type 4: - involving partial pressures
A 10.0 L flask at 25.0 °C contains 0.200 mol methane, 0.300 mol H2, and 0.400 mol N2. What is
the total pressure in atmospheres. What are the partial pressures of each of the gases? ans:
Pmethane 0.488 atm, PH2 0.733 atm, PN2 0.997 atm
Ptotal 2.198 atm
Problem Type 5: - involving reaction stoichiometry
Grade 11 Chemistry students, for a chemistry magic show, decide to “blow up” a rubber glove
using a chemical reaction
between sodium carbonate and 6 M HCl. Assuming the volume of the glove is 500 mL, the
temperature is 25.0 °C, the
pressure of the gas in the balloon is 1 atm, and the HCl is in excess, what mass of sodium
carbonate will be required for
this reaction. ans: 2.116 g
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Boyles’ Law
Use Boyles‟ Law to answer the following questions:
1)
1.00 L of a gas at standard temperature and pressure is compressed to 473 mL. What is the new
pressure of the gas?
2)
In a thermonuclear device, the pressure of 0.050 liters of gas within the bomb casing reaches 4.0
x 106 atm. When the bomb casing is destroyed by the explosion, the gas is released into the
atmosphere where it reaches a pressure of 1.00 atm. What is the volume of the gas after the
explosion?
3)
Synthetic diamonds can be manufactured at pressures of 6.00 x 104 atm. If we took 2.00 liters
of gas at 1.00 atm and compressed it to a pressure of 6.00 x 104 atm, what would the volume of
that gas be?
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4)
The highest pressure ever produced in a laboratory setting was about 2.0 x 106 atm. If we have a
1.0 x 10-5 liter sample of a gas at that pressure, then release the pressure until it is equal to
0.275 atm, what would the new volume of that gas be?
5)
Atmospheric pressure on the peak of Mt. Everest can be as low as 150 mm Hg, which is why
climbers need to bring oxygen tanks for the last part of the climb. If the climbers carry 10.0
liter tanks with an internal gas pressure of 3.04 x 104 mm Hg, what will be the volume of the gas
when it is released from the tanks?
6)
Part of the reason that conventional explosives cause so much damage is that their detonation
produces a strong shock wave that can knock things down. While using explosives to knock down a
building, the shock wave can be so strong that 12 liters of gas will reach a pressure of 3.8 x 10 4
mm Hg. When the shock wave passes and the gas returns to a pressure of 760 mm Hg, what will
the volume of that gas be?
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7)
Submarines need to be extremely strong to withstand the extremely high pressure of water
pushing down on them. An experimental research submarine with a volume of 15,000 liters has an
internal pressure of 1.2 atm. If the pressure of the ocean breaks the submarine forming a
bubble with a pressure of 250 atm pushing on it, how big will that bubble be?
8)
Divers get “the bends” if they come up too fast because gas in their blood expands, forming
bubbles in their blood. If a diver has 0.05 L of gas in his blood under a pressure of 250 atm, then
rises instantaneously to a depth where his blood has a pressure of 50.0 atm, what will the volume
of gas in his blood be? Do you think this will harm the diver?
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Charles’ Law Worksheet
1)
The temperature inside my refrigerator is about 40 Celsius. If I place a balloon in my fridge that
initially has a temperature of 220 C and a volume of 0.5 liters, what will be the volume of the
balloon when it is fully cooled by my refrigerator?
2)
A man heats a balloon in the oven. If the balloon initially has a volume of 0.4 liters and a
temperature of 20 0C, what will the volume of the balloon be after he heats it to a temperature
of 250 0C?
3)
On hot days, you may have noticed that potato chip bags seem to “inflate”, even though they have
not been opened. If I have a 250 mL bag at a temperature of 19 0C, and I leave it in my car which
has a temperature of 600 C, what will the new volume of the bag be?
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4)
A soda bottle is flexible enough that the volume of the bottle can change even without opening it.
If you have an empty soda bottle (volume of 2 L) at room temperature (25 0C), what will the new
volume be if you put it in your freezer (-4 0C)?
5)
Some students believe that teachers are full of hot air. If I inhale 2.2 liters of gas at a
temperature of 180 C and it heats to a temperature of 380 C in my lungs, what is the new volume of the
gas?
6)
How hot will a 2.3 L balloon have to get to expand to a volume of 400 L? Assume that the initial
temperature of the balloon is 25 0C.
7)
I have made a thermometer which measures temperature by the compressing and expanding of
gas in a piston. I have measured that at 1000 C the volume of the piston is 20 L. What is the
temperature outside if the piston has a volume of 15 L? What would be appropriate clothing for
the weather?
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Gay-Lussac’s Law Worksheet:
1. Determine the pressure change when a constant volume of gas at 1.00 atm is heated from 20.0 ˚C to 30.0 ˚C.
2.
A container of gas is initially at 0.500 atm and 25 ˚C. What will the pressure be at 125 ˚C?
3.
A gas container is initially at 47 mm Hg and 77 K (liquid nitrogen temperature.) What will the
pressure be when the container warms up to room temperature of 25 ˚C?
4.
A gas thermometer measures temperature by measuring the pressure of a gas inside the fixed
volume container. A thermometer reads a pressure of 248 Torr at 0 ˚C. What is the temperature
when the thermometer reads a pressure of 345 Torr?
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5.
A gas is collected at 22.0 ˚C and 745.0 mm Hg. When the temperature is changed to 0 ˚C, what is
the resulting pressure?
6.
A gas has a pressure of 699.0 mm Hg at 40.0 ˚C. What is the temperature at
standard pressure?
7.
If a gas is cooled from 323.0 K to 273.15 K and volume is kept constant what final pressure would
result if the original pressure was 750.0 mm Hg?
8.
The temperature of a sample of gas in a steel tank at 30.0 kPa is increased
from –100.0 ˚ to 1.00 x 103 ˚C to 25.0 ˚. What is the final pressure inside the tank?
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9.
Calculate the final pressure inside a scuba tank after it cools from 1.00 x 103 ˚C to 25.0 ˚C. The
initial pressure in the tank is 130.0 atm.
10.
A 30.0 L sample of nitrogen inside a rigid, metal container at 20.0 ˚C is placed
inside an oven whose temperature is 50.0 ˚C. The pressure inside the container at 20.0 ˚C was at
3.00 atm. What is the pressure of the nitrogen after its temperature is increased?
Combined Gas Law Problems
Use the combined gas law to solve the following problems:
1)
If I initially have a gas at a pressure of 12 atm, a volume of 23 liters, and a temperature of 200
K, and then I raise the pressure to 14 atm and increase the temperature to 300 K, what is the
new volume of the gas?
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2)
A gas takes up a volume of 17 liters, has a pressure of 2.3 atm, and a temperature of 299 K. If I
raise the temperature to 350 K and lower the pressure to 1.5 atm, what is the new volume of the
gas?
3)
A gas that has a volume of 28 liters, a temperature of 45 0C, and an unknown pressure has its
volume increased to 34 liters and its temperature decreased to 35 0C. If I measure the pressure
after the change to be 2.0 atm, what was the original pressure of the gas?
4)
A gas has a temperature of 14 0C, and a volume of 4.5 liters. If the temperature is raised to 29
0
C and the pressure is not changed, what is the new volume of the gas?
5)
If I have 17 liters of gas at a temperature of 67 0C and a pressure of 88.89 atm, what will be the
pressure of the gas if I raise the temperature to 94 0C and decrease the volume to 12 liters?
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6)
I have an unknown volume of gas at a pressure of 0.5 atm and a temperature of 325 K. If I raise
the pressure to 1.2 atm, decrease the temperature to 320 K, and measure the final volume to be
48 liters, what was the initial volume of the gas?
7)
If I have 21 liters of gas held at a pressure of 78 atm and a temperature of 900 K, what will be
the volume of the gas if I decrease the pressure to 45 atm and decrease the temperature to 750
K?
8)
If I have 2.9 L of gas at a pressure of 5 atm and a temperature of 50 0C, what will be the
temperature of the gas if I decrease the volume of the gas to 2.4 L and decrease the pressure to
3 atm?
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9)
I have an unknown volume of gas held at a temperature of 115 K in a container with a pressure of
60 atm. If by increasing the temperature to 225 K and decreasing the pressure to 30 atm causes
the volume of the gas to be 29 liters, how many liters of gas did I start with?
The Ideal and Combined Gas Laws
Use your knowledge of the ideal and combined gas laws to solve the following problems. Hint:
Figuring out which equation you need to use is the hard part!
1)
If four moles of a gas at a pressure of 5.4 atmospheres have a volume of 120 liters, what
is the temperature?
2)
If I initially have a gas with a pressure of 84 kPa and a temperature of 350 C and I heat
it an additional 230 degrees, what will the new pressure be? Assume the volume of the
container is constant.
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3)
My car has an internal volume of 2600 liters. If the sun heats my car from a
temperature of 200 C to a temperature of 550 C, what will the pressure inside my car be?
Assume the pressure was initially 760 mm Hg.
4)
How many moles of gas are in my car in problem #3?
5)
A toy balloon filled with air has an internal pressure of 1.25 atm and a volume of 2.50 L.
If I take the balloon to the bottom of the ocean where the pressure is 95 atmospheres,
what will the new volume of the balloon be? How many moles of gas does the balloon
hold? (Assume T = 285 K)
Gas Law Practice
Gas behavior can be explained qualitatively by using the kinetic molecular theory.
Gas molecules are moving constantly, filling the volume of the container in which
they are confined. Collisions between gas molecules and the walls of their
container cause gas pressure. The average kinetic energy of the gas molecules in
the container is directly proportional to the Kelvin temperature. Use these
concepts to solve the following problems.
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1. A welder uses oxygen in his oxyacetylene torch. At the beginning of the
work day, the gauge of the shows the internal gas pressure to be 2250 psi.
After work that day the welder checks the tank again and finds the
pressure to be 225 psi. What fraction of the gas molecules was used? (psi
stands for pounds per square inch, it is another unit of pressure)
2. At a birthday party a child sits on a partially filled balloon, decreasing its
volume by 1/2. What is the new pressure inside the balloon?
3. In a cryogenics (extreme cold) demonstration, a scientist takes a small,
partially inflated balloon out of liquid nitrogen (at a very low temperature).
As the balloon rests on the table, it begins to grow in size. Explain this
phenomenon.
4. The tank of an air compressor contains gas at normal atmospheric pressure
(1 atm). If the compressor motor pumps the equivalent of three extra tanks
of air into the compressor tank, what will be the final pressure?
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5. Huge weather balloons partially filled with helium are sent high into the
earth‟s atmosphere to examine the air. As a balloon rises into the air, the air
pressure outside the balloon decreases rapidly. If the atmospheric pressure
becomes one-third of its original pressure, what will happen to the balloon
volume? Explain.
6. Use the kinetic molecular theory to explain why on a cold autumn morning a
camper‟s air mattress may appear to be somewhat flatter than it was when
blown up the afternoon before. Assume no leaks.
Graphing Gas-Law Relationships The various gas laws express the relationships
between quantities such as pressure, volume, and temperature representing the
variations between pressure, volume, and temperature data helps to reveal the
mathematical nature of the relationships. Consider the two examples that follow:
7. An expandable container is filled with a given volume of gas. While the pressure
of the gas is kept constant, the container is heated. The temperature is recorded
in degrees Celsius, and the volume of the contained gas is recorded as well. The
data are shown in the following table.
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Temperature (°C)
0°C
50°C
100°C
150°C
Temperature (K)
____________
____________
____________
____________
Volume
293 mL
347 mL
401 mL
455 mL
Convert °C into Kelvin‟s and write these values into the table.
Then plot the data on the graph paper over the page
Answer the questions
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a. What type of proportion does this graph illustrate? Explain.
b. What is the value of V/T for this experiment?
c. To what graphical quantity does V/T correspond?
d. Is V/T constant or does it vary?
e. Extrapolate values for the volume occupied by the gas at
150 K______ 75 K_______ 0 K________
f. What gas law does the graph illustrate?
g. Express this relationship in the form of a mathematical equation.
-
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8. The piston in the following figure is moving further into the
cylinder. As it moves, both the pressure and volume of the
contained gas are measured. The data are shown in the following
table. Graph this data using graph paper over the page and answer
the accompanying questions.
Volume
Pressure
3
500 cm
1 atm
250 cm3
2 atm
3
167 cm
3 atm
125 cm3
4 atm
100 cm3
5 atm
3
83 cm
6 atm
71 cm3
7 atm
3
63 cm
8 atm
56 cm3
9 atm
50 cm3
10 atm
a. What type of proportion does this graph illustrate? Explain.
b. If the cylinder can suddenly accommodate a volume of 1000 cm3. Predict the
corresponding pressure value.
c. What pressure will be observed if the volume of the contained gas equals
375 cm3?
d. Which gas law does the graph illustrate? Express this relationship in the
form of a mathematical equation.
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9. Carbon monoxide gas reacts with oxygen gas to form carbon dioxide gas.
Write a balanced equation for the reaction. Remember that oxygen gas is
diatomic.
10.
Given Avogadro's Hypothesis, what volume of oxygen will you expect to
completely react with 4.0 L of carbon monoxide, if both gases are at the
same temperature and pressure?
11. If the 4.0 L of carbon monoxide above contains 1.08 x 1023 molecules, how
many molecules of oxygen will you find in 2.6 L of oxygen gas at the same
temperature and pressure?
13. Avogadro‟s Hypothesis states that equal volumes of gases (at the same
temperature and pressure) contain equal numbers of particles. If instead you have
equal masses of the three gases in the reaction above, which gas will occupy the
largest volume assuming the gasses are all at the same temperature
and pressure? Explain.
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Gas Law Practice
1. Change 125 mL of a gas at 25 °C to standard temperature. 114.5 mL
2. Change 300 mL of a gas at 0 °C to 30 °C. 333 mL
3. Change 220 mL of a gas at 10 °C to 100 °C. 290 mL
4. Change 1.0 L of a gas at 32 °C to 27 °C. 0.98 L
5. Change 100 mL of a gas at 740 torr to standard pressure. 97.4 mL
6. Change 250 mL of a gas at standard pressure to 780 torr. 243.6 mL
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7. Change 30 mL of a gas at standard pressure to 600 torr. 38 mL
8. Change 750 mL of a gas at 700 torr to 800 torr. 656 mL
9. Change 500 mL of a gas at 60 °C and 800 torr to S.T.P. 431.5 mL
10.
Change 800 mL of a gas at 40 °C and 700 torr to S.T.P. 642.6 mL
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Gas Stoichiometry Practice Sheet
1)
For the reaction 2 H2(g) + O2(g)  2 H2O(g), how many liters of water can be made from 5 L of
oxygen gas and an excess of hydrogen?
2)
How many liters of water can be made from 55 grams of oxygen gas and an excess of hydrogen at
STP?
3)
How many liters of water can be made from 55 grams of oxygen gas and an excess of hydrogen at
a pressure of 12.4 atm and a temperature of 850 C?
4)
How many liters of water can be made from 34 grams of oxygen gas and 6.0 grams of hydrogen
gas at STP? What is the limiting reactant for this reaction?
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Gas Stoichiometry Practice Sheet Answers
1)
For the reaction 2 H2(g) + O2(g)  2 H2O(g), how many liters of water can be made from 5 L of
oxygen gas and an excess of hydrogen?
10 L
2)
How many liters of water can be made from 55 grams of oxygen gas and an excess of hydrogen at
STP?
77 L
3)
How many liters of water can be made from 55 grams of oxygen gas and an excess of hydrogen at
a pressure of 12.4 atm and a temperature of 850 C?
8.15 L
4)
How many liters of water can be made from 34 grams of oxygen gas and 6.0 grams of hydrogen
gas at STP? What is the limiting reactant for this reaction?
47.6 L, O2 is the limiting reactant
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Gas Stoichiometry Problems
1. What volume of nitrogen at STP would be required to react with 0.100 mol of
hydrogen to produce ammonia? 0.75L N2
N2(g) +3H2 (g) → 2NH3(g)
2. What volume of nitrogen at 215°C and 715 mm Hg would be required to react
with 0.100 mol of hydrogen to produce ammonia? 1.43 L N2
N2(g) +3H2 (g) → 2NH3(g)
3. What volume of nitrogen at STP would be required to react with 0.100 g of
hydrogen to produce ammonia? 0.37 L N2
N2(g) +3H2 (g) → 2NH3(g)
4. What volume of dry NO(g) at STP could be produced by reacting 8.74 g of Cu
with and excess of HNO3 ? 2.06 L NO
3 Cu + 8 HNO3 → 3 Cu(NO3)2 + 2NO(g) + 4 H2O(l)
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5. What volume of hydrogen would be required to produce 0.400 mole of HCl at
STP? 4.48 L H2
H2(g)+Cl2 (g) → 2HCl(g)
6. What volume of hydrogen would be required to produce 0.400 mole of HCl at
57°C and 450 mm Hg? 9.16 L H2
H2(g)+Cl2 (g) → 2HCl(g)
7. If 0.500 mole of carbon disulfide reacts with oxygen completely according to
the following reaction what would the total volume of the products be at 25°C and
4.23 atm? 8.67 L
CS2(l) + 3 O2 (g) → CO2 (g) + 2 SO2 (g)
8. If 13.5 g of aluminum is reacted with excess hydrochloric acid in a 2.0 L bottle
at 26°C, what would the
pressure be? 1.09 atm
2Al(s) + 6 HCl (aq) →2AlCl3 (aq) + 3 H2 (g)
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Extension Dalton’s Law Practice Problems
1)
Three flasks are connected to each other, separated only by a three-way stopcock.
 Flask 1 has a volume of 3.000 liters and holds helium gas at a pressure of 3.500
atmospheres
 Flask 2 has a volume of 2.000 liters and holds nitrogen gas at a pressure of 2.000
atmospheres
 Flask 3 has a volume of 1.800 liters and holds oxygen gas at a pressure of 4.000
atmospheres
If the stopcock separating the flasks were to be opened, what would the partial pressure
of each gas in the apparatus be?
2)
What would the total pressure in the apparatus be?
3)
What would the mole fraction of oxygen be inside the apparatus after the stopcock was
opened?
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4)
If liquid water is added to the mixture, what will the mole fraction of each of the gases
in the mixture be? The vapor pressure of water at 250 C is 0.031 atm.
5) A metal tank contains three gases: oxygen, helium, and nitrogen. If the partial pressures of the
three gases in the tank are 35 atm of O2, 5 atm of N2, and 25 atm of He, what is the total pressure
inside of the tank?
65 atm
6)
Blast furnaces give off many unpleasant and unhealthy gases. If the total air pressure is 0.99
atm, the partial pressure of carbon dioxide is 0.05 atm, and the partial pressure of hydrogen
sulfide is 0.02 atm, what is the partial pressure of the remaining air?
0.92 atm
7)
If the air from problem 2 contains 22% oxygen, what is the partial pressure of oxygen near a
blast furnace?
0.92 x 0.22 = 0.20 atm
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Molarity Calculations
Calculate the molarities of the following solutions:
1)
2.3 moles of sodium chloride in 0.45 liters of solution.
2)
1.2 moles of calcium carbonate in 1.22 liters of solution.
3)
0.09 moles of sodium sulfate in 12 mL of solution.
4)
0.75 moles of lithium fluoride in 65 mL of solution.
5)
0.8 moles of magnesium acetate in 5 liters of solution.
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6)
120 grams of calcium nitrite in 240 mL of solution.
7)
98 grams of sodium hydroxide in 2.2 liters of solution.
8)
1.2 grams of hydrochloric acid in 25 mL of solution.
9)
45 grams of ammonia in 0.75 L of solution.
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Explain how you would make the following solutions. You should tell how many grams of the substance
you need to make the solution, not how many moles.
10)
2 L of 6 M HCl
11)
1.5 L of 2 M NaOH
12)
0.75 L of 0.25 M Na2SO4
13)
45 mL of 0.12 M sodium carbonate
14)
250 mL of 0.75 M lithium nitrite
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15)
56 mL of 1.1 M iron (II) phosphate
16)
6.7 L of 4.5 M ammonium nitrate
17)
4.5 mL of 0.05 M magnesium sulfate
18)
90 mL of 1.2 M BF3
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Concentration Practice Worksheet
1)
If I make a solution by adding water to 75 mL of ethanol until the total volume of the solution is
375 mL, what‟s the percent by volume of ethanol in the solution?
2)
If I add 1.65 L of water to 112 grams of sodium acetate…
a)
What is the molality of NaC2H3O2 in this solution?
b)
What is the percent by mass of sodium acetate in this solution?
c)
What is the mole fraction of water in this solution?
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Molarity Calculations
1. How many grams of K2SO4 will be required to prepare 1.0 liters of 0.5M
potassium sulfate solution?
87 g
2. If 12 g of NaOH are dissolved in enough water to make 500 mL of solution,
what is the molarity of the solution? 0.6 M
3. A solution of Cu(NO3)2 contains 100 g of solute per liter of solution. What is
the molarity of the solution? 0.53 M
4. A solution of NaCl contains 12 g of NaCl in 750 mL „s of solution. What is the
molarity of the solution?
0.27 M
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5. How many grams of aluminum sulfate will be required to prepare 300 mL‟s of
0.2M Al2(SO4)3 solution?
20.5 g
6. Describe how you would make each of the following solutions:
a) From 100 mL‟s of 4.0 M H2SO4 prepare a 0.002 M solution.
Add enough water to the original solution to make 200L
b) From 100 mL‟s of 6.0 M H2SO4 prepare a 0.002 M solution. Add enough water
to the original solution to make 300L
c) From 100 mL‟s of 0.5 M H2SO4 prepare a 0.002 M solution.
Add enough water to the original solution to make 25L
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7. Complete the following table by making the appropriate calculations
8. How many grams of sulfuric acid are needed to produce 2 L of 3M acid?
9. Determine the molarity of a solution which contains 23 grams of magnesiumm
bromide in 400 mL of solution.
10. In what volume of solution must 27 grams of zinc chloride be dissolved in
order to prepare a 0.1M solution?
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11. How would you prepare 60 mL of 0.2M solution of barium chloride from solid
barium chloride?
12. How much water must be added to 25 mL of a 0.5M solution to prepare a 0.1M
solution?
13. How much 15M acid is needed to prepare 5 L of 3M acid?
14. How would you prepare 150 mL of 0.4M sodium sulfate from a 2M stock
solution? (complete sentences needed here!).
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Dilutions Worksheet
1)
If I have 340 mL of a 0.5 M NaBr solution, what will the concentration be if I add 560 mL more
water to it?
2)
If I dilute 250 mL of 0.10 M lithium acetate solution to a volume of 750 mL, what will the
concentration of this solution be?
3)
If I leave 750 mL of 0.50 M sodium chloride solution uncovered on a windowsill and 150 mL of the
solvent evaporates, what will the new concentration of the sodium chloride solution be?
4)
To what volume would I need to add water to the evaporated solution in problem 3 to get a
solution with a concentration of 0.25 M?
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Concentration, Molarity, and the Making of a Solution.
1. A 25.00 g sample of glucose was weighed out and added to a 100.00 mL
volumetric flask. Enough distilled water was added to fill to the volume line
of the flask. The lid was secured and the flask inverted about 20 times.
What is the concentration of the glucose solution?
2. A 12.50 ml sample was removed from the volumetric flask and transferred to
a beaker. How many moles of glucose were transferred to the beaker?
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3. If you needed 8.50 g of glucose to do an experiment what volume would you
take from the volumetric flask?
4. Suggest a method to prepare a glucose solution that has 1/10th the
concentration as the one
described in question 1.
Titrations Worksheet
1. If it takes 54ml of 0.1 mol dm-3 NaOH to neutralise 125ml of a HCl solution
what is the concentration of HCl?
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2. If it takes 25ml of 0.05 mol dm-3 HCl to neutralize 345 ml of a NaOH
solution, what is the concentration of the NaOH solution?
3. If it takes 50ml of a 0.5 mol dm-3 KOH solution to completely neutralize 125
ml of sulphuric acid solution (H2SO4), what is the concentration of the
sulphuric acid solution?
4. Can I titrate a solution of unknown concentration with another solution of
unknown concentration and still get a meaningful answer? Explain your
answer in a few sentences.
5. Explain the difference between an endpoint and equivalence point in a
titration.
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Molarity of Ions Practice
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Topic 1 Review
Reacting masses
1. When heated potassium chlorate(V) decomposes to form potassium chloride and oxygen. The
unbalanced equation is: KClO3
(s)
 KCl (s) + O2 (g)
(a) Balance the equation.
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(b) Calculate how many moles of KClO3 are needed to produce 0.60 moles of oxygen.
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(c) What mass of KClO3 is needed to produce 0.0200 moles of KCl?
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2. What mass of copper(II) sulfate pentahydrate (CuSO4 · 5H2O) can be produced by reacting 12.00
g of copper(II) oxide with an excess of sulfuric acid?
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3. Pure compound A contains 63.3% manganese and 36.7% oxygen by mass. Upon heating compound
A, oxygen is evolved and pure compound B is formed which contains 72.0% manganese and 28.0%
oxygen by mass.
(a) Determine the empirical formula for compounds A and B.
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(b) Write a balanced equation which represents the reaction that took place.
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(c) Calculate how many grams of oxygen would be evolved when 2.876 g of A is heated to form
pure B.
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Limiting reagents
4. Consider the reaction:2 Al (s) + 3 I2 (s)  2 AlI3 (s) Determine the limiting reagent and the
theoretical yield of the product from:
(a) 1.20 mol aluminium and 2.40 mol iodine.
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(b) 1.20 g aluminium and 2.40 g iodine.
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(c) Calculate how many grams of aluminium are left over in part b.
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5. Freon-12 (used as coolant in refrigerators), is formed as follows:
3 CCl4 (l) + 2 SbF3 (s)  3 CCl2F2 (g) + 2 SbCl3 (s) 150 g
tetrachloromethane is combined with 100 g antimony(III) fluoride to give Freon-12 (CCl2F2).
(a) Identify the limiting and excess reagents.
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6. (b) Calculate how many grams of Freon-12 can be formed.
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(c) How much of the excess reagent is left over?
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7. Aspirin is made by adding acetic anhydride to an aqueous solution of salicylic acid. The equation
for the reaction is:
2 C7H6O3 (aq) +
salicylic acid
C4H6O3 (l)
acetic anhydride

2C9H8O4 (aq) + H2O (l)
aspirin
water
If 1.00 kg of salicylic acid is used with 2.00 kg of acetic anhydride, determine:
(a) the limiting reagent.
……………………………………………………………………………………………………………………………………………………………
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(b) the theoretical yield.
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(c) If 1.12 kg aspirin is produced experimentally, determine the percentage yield.
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Avogadro’s Principle
8. A mixture of 20 cm3 hydrogen and 40 cm3 oxygen is exploded in a strong container. After cooling
to the original temperature and pressure (at which water is a liquid) what gas, if any, will remain
in the container?
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9.
To three signifficant figures, calculate how many methane molecules are there in 4.48 dm3 of
the gas at standard temperature and pressure?
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10. If 3.00 dm3 of an unknown gas at standard temperature and pressure has a mass of 6.27 g,
Determine the molar mass of the gas.
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11. Determine the density of ammonia, in g dm–3, at s.t.p.
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12. Sulfur dioxide, present in flue gases from the combustion of coal, is often absorbed by injecting
powdered limestone into the flame, when the following reactions occur:
CaCO3 (s)  CaO (s) + CO2 (g)
CaO (s) + SO2 (g)  CaSO3 (s)
What volume of sulfur dioxide, measured at s.t.p., can be absorbed by using 1 tonne (1.00 × 106 g)
of limestone in this way?
……………………………………………………………………………………………………………………………………………………………
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Ideal Gas equation
13. In a particular experiment aluminium was reacted with dilute hydrochloric acid according to the
equation:
2 Al (s) + 6 HCl (aq)  2 AlCl3 (aq) + 3 H2 (g)
355 cm3 of hydrogen was collected at 25.0 oC a pressure of 100.0 kPa.
a) Calculate how many moles of hydrogen were collected.
…………………………………………………………………………………………………………………………………………………………………
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b) If 0.300 g of aluminium was used with excess acid, determine the percentage yield of
hydrogen.
…………………………………………………………………………………………………………………………………………………………………
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14. A steel cylinder contains 32 dm3 of hydrogen at 4 × 105 Pa and 39 oC. Calculate
a) The volume that the hydrogen would occupy at s.t.p. (oC and 101.3 kPa)
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b) The mass of hydrogen in the cylinder.
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15. The following readings were taken during the determination of the molar mass of a gas by direct
weighing. If the experiment was carried out at 23 oC and 97.7 kPa, calculate the molar mass of
the gas. Mass of evacuated flask 183.257g
Mass of flask and gas 187.942g
Mass of flask filled with water 987.560g.
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16. Two 5 dm3 flasks are connected by by a narrow tube of negligible volume. Initially the two flasks
are both at 27 oC and contain a total of 2 moles of an ideal gas. One flask is heated to a uniform
temperature of 127 oC while the other is kept at 27 oC. Assuming their volume does not alter,
calculate the number of moles of gas in each flask of the gas and the final pressure.
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Solutions
17. What are the concentrations of the solutions produced by dissolving
a) 3.0 moles of nitric acid in 4.0 dm3 of solution?
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b) 2.81 g of KOH in 2.00 dm3 of solution?
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c) 5.00 g of magnesium sulfate heptahydrate in 250 cm3 of solution?
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18. Calculate how many moles are there in the following:
a) 7.0 dm3 of sulfuric acid of concentration 0.30 mol dm–3.
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b) 50 cm3 of a 0.040 mol dm–3 solution of lithium chloride.
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c) 15.0 cm3 of a solution made by dissolving 5.80 g of zinc chloride in 2.50 dm3 of solution.
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19. How would you prepare 500 cm3 of a 0.100 mol dm–3 NaCl solution?
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20. How would you prepare 1.2 dm3 of a 0.40 mol dm–3 solution of hydrochloric acid starting from a
2.0 mol dm-3 solution?
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21. 500 cm3 of 0.500 mol dm–3 NaCl is added to 500 cm3 of 1.00 mol dm–3 Na2CO3 solution. Calculate
the Final concentration of Na+ ions in solution.
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Titration Calculation
22. 20 cm3 of hydrochloric acid was just neutralised by 25.0 cm3 of a solution of potassium hydroxide
of concentration 0.500 mol dm–3.
(a) Calculate how many moles of potassium hydroxide were used in the reaction.
…………………………………………………………………………………………………………………………………………………………………
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(b) Calculate how many moles of hydrochloric acid this reacted with.
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(c) What was the concentration of the hydrochloric acid?
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23. 25.0 cm3 of saturated calcium hydroxide solution (limewater) required 7.50 cm3 of 0.0500 mol
dm–3 nitric acid to just neutralise it.
(a) Calculate how many moles of nitric acid were used.
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(b) Calculate how many moles of calcium hydroxide did this react with.
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(c) Determine the concentration of the calcium hydroxide in grams per liter.
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24. A 0.245 g sample of a mixture of calcium chloride and sodium nitrate is dissolved in water to give
50.0 cm3 of solution. This solution is titrated with 0.106 mol dm-3 aqueous silver nitrate which
reacts with the chloride ions present to form insoluble silver chloride. The end point is reached
after 37.7 cm3 of the silver nitrate solution has been added.
(a) Write a balanced chemical equation for the reaction, including state symbols.
…………………………………………………………………………………………………………………………………………………………………
(b) Calculate the amount of silver nitrate used in the titration.
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(c) Calculate the amount of calcium chloride present in the solution.
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(d) Calculate the percentage by mass of calcium chloride in the original mixture.
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25. The number of moles of water of crystallisation (x) present in hydrated ammonium iron(II)
sulfate, Fe(NH4)2(SO4)2•xH2O, can be determined by oxidising the iron(II) ions with aqueous
potassium permanganate in acidified solution. The ionic equation for the reaction is
MnO4– (aq) + 5 Fe2+
(aq)
+ 8 H+ (aq)  Mn2+
(aq)
+ 5 Fe3+
(aq)
+ 4 H2O (l)
It is found that when 0.980 g of the compound is dissolved in 25.0 cm3 of water and titrated with
0.0300 mol dm–3 aqueous permanganate, 16.7 cm3 are required for complete reaction.
(a) Calculate the amount of potassium permanganate used in the titration.
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(b) Calculate the amount of iron(II) ions present in the solution.
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(c) Given that the molar mass of Fe(NH4)2(SO4)2 is 284 g mol–1, calculate the mass of anhydrous
solid that must have been present.
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(d) Calculate the mass of water present in the crystals and hence the value of x.
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26. Concentrated hydrochloric acid has a density of 1.15 g cm–3 and contains 30.0% by mass hydrogen
chloride.
(a) Determine the concentration of the hydrochloric acid.
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(b) What volume of this must be diluted to 5.00 dm3 to give a solution of concentration 0.200 mol
dm–3.
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27. 0.130 g of a sample of impure iron was dissolved in excess dilute sulfuric acid to form iron(II)
sulfate. This was then titrated with a 0.0137 mol dm–3 solution of dichromate ions (Cr2O72–) and
was found to be just sufficient to reduce 27.3 cm3 of the solution to chromium(III) ions (Cr3+)
(a) Write a balanced ionic equation for the titration reaction.
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(b) Calculate the amount of dichromate ion used in the reaction.
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(c) Calculate the amount of iron(II) ions present in the solution.
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(d) Calculate the percentage purity (by mass) of the iron.
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Back Titration
28. Aspirin is a sparingly soluble monobasic acid. 1.0 g of impure aspirin (C9H8O4) was added to 10 cm3
of
3
1.0 mol dm–3 aqueous sodium hydroxide. The excess base was then titrated with 0.20 mol dm–
hydrochloric acid and 25 cm3 were needed to neutralise the excess alkali.
a) Calculate how many moles of hydrochloric acid were used.
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b) Calculate how many moles of sodium hydroxide were taken initially.
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c) Calculate how many moles of aspirin were present in the tablet.
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d) What mass of aspirin does this correspond to?
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e) What was the percentage purity of the aspirin?
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29. A 20.0 g block of impure marble was dissolved in 250 cm3 of 2.00 mol dm–3 nitric acid. When the
block completely dissolved, 25.0 cm3 of the solution was titrated with 1.00 mol dm–3 aqueous
sodium hydroxide and 17.0 cm3 were required for neutralisation. What percent by mass of the
marble was calcium carbonate. What assumptions did you make in calculating this?
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30. 0.600g of a metal M was dissolved in 200 cm3 of 0.500 mol dm–3 hydrochloric acid. 25.0 cm3 of
2.00 mol dm–3 aqueous sodium hydroxide were required to neutralise the excess acid. Calculate
the molar mass of the metal assuming that the formula of its chloride is:
a) MCl
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b) MCl2
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c) MCl3
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Which do you consider to be the more likely value? Why?
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IB Exam Questions For Topic 1 Quantitative Chemistry
1.
Which compound has the empirical formula with the largest mass?
A.
C2H6
B.
C2H4
C.
C2H2
D.
C3H6
(Total 1 mark)
2.
What volume of sulfur trioxide, in cm3, can be prepared using 40 cm3 sulfur dioxide and 20 cm3 oxygen gas
by the following reaction? Assume all volumes are measured at the same temperature and pressure.
2SO2(g) + O2(g) → 2SO3(g)
A.
20
B.
40
C.
60
D.
80
(Total 1 mark)
3.
Which sample has the greatest mass?
A.
6.0 × 1025 molecules of hydrogen
B.
5.0 mol of neon atoms
C.
1.2 × 1024 atoms of silver
D.
1.7 × 102 g of iron
(Total 1 mark)
4.
How many oxygen atoms are there in 0.20 mol of ethanoic acid, CH3COOH?
A.
1.2 × 1023
B.
2.4 × 1023
C.
3.0 × 1024
D.
6.0 × 1024
(Total 1 mark)
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Version 1 2012
5.
The molar mass of a compound is approximately 56 g mol–1. Which formula is possible for this compound?
A.
NaNO3
B.
AgOH
C.
MgO
D.
KOH
(Total 1 mark)
6.
Which sample of nitrogen gas, N2, contains the greatest number of nitrogen molecules?
A.
1.4 g N2
B.
1.4 dm3 of N2 at 1.01 × 105 Pa and 273 K
C.
1.4 × 1023 N2 molecules
D.
1.4 mol N2
(Total 1 mark)
7.
What is the coefficient for O2(g) when the equation for the combustion of 1 mole of pentane is balanced?
C5H12(g) + _O2(g) → _CO2(g) + _H2
A.
5
B.
6
C.
8
D.
16
(Total 1 mark)
8.
Which coefficients would balance this equation?
__ MnO2 + __ HCl → __ MnCl2 + __ Cl2 + __ H2O
MnO2
HCl
MnCl2
Cl2
H2O
A.
1
2
1
1
1
B.
1
3
1
1
1
C.
1
4
1
1
2
D.
1
4
1
2
2
(Total 1 mark)
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Version 1 2012
9.
4.00 mol of a hydrocarbon with an empirical formula of CH2 has a mass of 280 g. What is the molecular
formula of this compound?
A.
C2H4
B.
C3H6
C.
C4H8
D.
C5H10
(Total 1 mark)
10.
What volume of carbon dioxide, in dm3 under standard conditions, is formed when 7.00 g of ethene (C2H4,
Mr = 28.1) undergoes complete combustion?
A.
22.4  28.1
7.00
B.
22.4  7.00
28.1
C.
2  22.4  28.1
7.00
D.
2  22.4  7.00
28.1
(Total 1 mark)
¬G11. The volume of an ideal gas at 27.0 °C is increased from 3.00 dm3 to 6.00 dm3. At what temperature, in °C,
will the gas have the original pressure?
A.
13.5
B.
54.0
C.
327
D.
600
(Total 1 mark)
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Version 1 2012
12.
What is the maximum mass, in g, of magnesium oxide that can be obtained from the reaction of oxygen with
2.4 g of magnesium?
A.
2.4
B.
3.0
C.
4.0
D.
5.6
(Total 1 mark)
13.
What will be the concentration of sulfate ions in mol dm–3 when 0.20 mol of KAl(SO4)2 is dissolved in water
to give 100 cm3 of aqueous solution?
A.
0.2
B.
1.0
C.
2.0
D.
4.0
(Total 1 mark)
14.
What is the number of oxygen atoms in one mole of CuSO4•5H2O?
A.
5
B.
9
C.
6.0 × 1023
D.
5.4 × 1024
(Total 1 mark)
15.
Which non-metal forms an oxide XO2 with a relative molecular mass of 60?
A.
C
B.
N
C.
Si
D.
S
(Total 1 mark)
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16.
5 dm3 of carbon monoxide, CO(g), and 2 dm3 of oxygen, O2(g), at the same temperature and pressure are
mixed together. Assuming complete reaction according to the equation given, what is the maximum volume
of carbon dioxide, CO2(g), in dm3, that can be formed?
2CO(g) + O2(g) → 2CO2
A.
3
B.
4
C.
5
D.
7
(Total 1 mark)
17.
Which statement about solutions is correct?
A.
When vitamin D dissolves in fat, vitamin D is the solvent and fat is the solute.
B.
In a solution of NaCl in water, NaCl is the solute and water is the solvent.
C.
An aqueous solution consists of water dissolved in a solute.
D.
The concentration of a solution is the amount of solvent dissolved in 1 dm3 of solution.
(Total 1 mark)
18.
Smog is common in cities throughout the world. One component of smog is PAN (peroxyacylnitrate) which
consists of 20.2 % C, 11.4 % N, 65.9 % O and 2.50 % H by mass.
Determine the empirical formula of PAN, showing your working.
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
(Total 3 marks)
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19.
Biodiesel makes use of plants’ ability to fix atmospheric carbon by photosynthesis.
Many companies and individuals are now using biodiesel as a fuel in order to reduce their carbon footprint.
Biodiesel can be synthesized from vegetable oil according to the following reaction.
(a)
Identify the organic functional group present in both vegetable oil and biodiesel.
......................................................................................................................................
(1)
(b)
For part of her extended essay investigation into the efficiency of the process, a student reacted a pure
sample of a vegetable oil (where R = C17H33) with methanol.
The raw data recorded for the reaction is below.
Mass of oil
Mass of methanol
Mass of sodium hydroxide
Mass of biodiesel produced
= 1013.0 g
= 200.0 g
=
3.5 g
= 811.0 g
The relative molecular mass of the oil used by the student is 885.6. Calculate the amount (in moles) of
the oil and the methanol used, and hence the amount (in moles) of excess methanol.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(3)
(c)
The reversible arrows in the equation indicate that the production of biodiesel is an equilibrium
process.
(i)
State what is meant by the term dynamic equilibrium.
...........................................................................................................................
...........................................................................................................................
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(1)
(ii)
Using the abbreviations [vegetable oil], [methanol], [glycerol] and [biodiesel] deduce the
equilibrium constant expression (Kc) for this reaction.
(1)
(iii)
Suggest a reason why excess methanol is used in this process.
...........................................................................................................................
...........................................................................................................................
(1)
(iv)
State and explain the effect that the addition of the sodium hydroxide catalyst will have on the
position of equilibrium.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(d)
The reactants had to be stirred vigorously because they formed two distinct layers in the reaction
vessel. Explain why they form two distinct layers and why stirring increases the rate of reaction.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(e)
Calculate the percentage yield of biodiesel obtained in this process.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
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(f)
When biodiesel is combusted it produces carbon dioxide. Explain why the use of biodiesel as a fuel
does not significantly contribute to global warming.
......................................................................................................................................
......................................................................................................................................
(1)
(Total 14 marks)
20.
The data below is from an experiment used to determine the percentage of iron present in a sample of iron
ore. This sample was dissolved in acid and all of the iron was converted to Fe2+. The resulting solution was
titrated with a standard solution of potassium manganate(VII), KMnO4. This procedure was carried out three
times. In acidic solution, MnO4– reacts with Fe2+ ions to form Mn2+ and Fe3+ and the end point is indicated
by a slight pink colour.
titre
(a)
1
2
3
initial burette reading / cm3
1.00
23.60
10.00
Final burette reading / cm3
24.60
46.10
32.50
Mass of iron ore / g
3.682 × 10–1
concentration of KMnO4 solution / mol dm–3
2.152 × 10–2
Deduce the balanced redox equation for this reaction in acidic solution.
......................................................................................................................................
......................................................................................................................................
(2)
(b)
Identify the reducing agent in the reaction.
......................................................................................................................................
(1)
(c)
Calculate the amount, in moles, of MnO4– used in the titration.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
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(d)
Calculate the amount, in moles, of Fe present in the 3.682 × 10–1 g sample of iron ore.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(e)
Determine the percentage by mass of Fe present in the 3.682 × 10–1 g sample of iron ore.
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
......................................................................................................................................
(2)
(Total 9 marks)
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Topic 1 Exam Question Markscheme
1.
A
[1]
2.
B
[1]
3.
C
[1]
4.
B
[1]
5.
D
[1]
6.
D
[1]
7.
C
[1]
8.
C
[1]
9.
D
[1]
10.
D
[1]
11.
C
[1]
12.
C
[1]
13.
D
[1]
14.
D
[1]
15.
C
[1]
16.
B
[1]
17.
B
[1]
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Version 1 2012
18.
C
20.2
12.01
= 1.68
1.68
=2
0.814
N
11.4
14.01
= 0.814
0.814
=1
0.814
O
65.9
16.00
= 4.12
4.12
=5
0.814
H
2.50
1.01
= 2.48
;
2.48
=3 ;
0.814
C2NO5H3;
No penalty for use of 12, 1 and/or 14.
Award [1 max] if the empirical formula is correct, but no working shown.
3
[3]
19.
(a)
ester;
(b)
amount of oil =
(c)
1013.0
= 1.144 mol;
885.6
200.0
amount of methanol =
= 6.240 mol;
32.05
since three mol of methanol react with one mol of vegetable oil the
amount of excess methanol = 6.204 – (3 × 1.144) = 2.808 mol;
(i)
rate of the forward reaction is equal to the rate of the reverse reaction /
forward and reverse reactions occur and the concentrations of the
reactants and products do not change / OWTTE;
[glycerol] [biodiesel] 3
1
Kc =
(iii)
to move the position of equilibrium to the right/product side /
increase the yield of biodiesel;
1
no effect (on position of equilibrium);
increases the rate of the forward and the reverse reactions equally
(so equilibrium reached quicker) / it lowers Ea for both the
forward and reverse reactions by the same amount / OWTTE;
No ECF for explanation.
2
[ vegetable oil] [methanol]3
;
3
(ii)
(iv)
(d)
1
vegetable oil is mainly non-polar and methanol is polar / OWTTE;
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1
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(e)
(f)
stirring brings them into more contact with each other / increase the
frequency of collisions / OWTTE;
Do not allow simply mixing.
2
(relative molecular mass of biodiesel, C9H36O2 = 296.55)
maximum yield of biodiesel = 3.432 mol / 1018 g;
811.0
percentage yield =
× 100 = 79.67 %;
1018
Allow 80 % for percentage yield.
2
the carbon dioxide was absorbed by plants initially so there is no net
increase / vegetable oil is not a fossil fuel / vegetable oil is formed
from (atmospheric) carbon dioxide / OWTTE;
1
[14]
20.
(a)
(b)
(c)
(d)
(e)
MnO4–(aq) + 5Fe2+(aq) + 8H+(aq) → Mn2+(aq) + 5Fe3+(aq) + 4H2O(l)
Award [2] if correctly balanced.
Award [1] for correctly placing H+ and H2O.
Award [1 max] for correct balanced equation but with electrons shown.
Ignore state symbols.
2
Fe2+/ iron(II);
Do not accept iron.
1
n = 2.152 × 10–2 × 2.250 × 10–2;
4.842 × 10–4 (mol);
Award [1] for correct volume
Award [1] for correct calculation.
2
1 mol of MnO4– reacts with 5 mol of Fe2+;
5 × 4.842 × 10–4 = 2.421 × 10–3 (mol);
(same number of moles of Fe in the iron ore)
Allow ECF from part (a) and (c) provided some mention of mole ratio
is stated.
2
2.421 × 10–3 × 55.85 = 0.1352(g);
0.1352
× 100 = 36.72 %;
0.3682
Allow ECF from part (d).
2
[9]
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