Download Introduction to Chemistry and the Metric System

1
Chemistry Final Exam Review
Introduction to Chemistry and the Metric System
Good things to know:
 scientific method - hypothesis, theory, data
 graphing - independent variable, dependent variable
 pure science vs. applied science
 chemistry, hazard symbols, common laboratory equipment
 accuracy vs. precision
 SI system of measurement
Problems:
1. How many significant figures in:
_____ a. 345
______b. 0.00540
_____ c. 300,000
2. Convert the following to scientific notation:
a. 3,000,020,000
b. 0.000002546
______d. 45.00010
3. Convert the following to decimal notation:
10
-9
a. 6.020 x 10
b. 3.5582 x 10
4. 3.55 x 10 = ?
6.
312
6 x 10 4
7.
456.0
2.0000
5. 2.0450 x 0.0044 = ?
8.
40.55.45 x 10 -5 
2.04 x 10 
12

3.0456.032 x 1023 
1.2 x 10 7.00 x 10 
9.
5
10. 35 + 40.02 + 450 = ?
11. 60.320 - 20.4444 = ?
12. 3.44 L = ? mL
13. 0.00430 km = ? cm
14. 0.456 MHz = ? Hz
15. 40.5 cm = ? dm
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3
10

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Matter & Energy
Good things to know:
 matter, conservation of matter, conservation of energy
 substances, elements, compounds, heterogeneous mixtures, homogeneous mixtures - solutions
 physical and chemical change, physical and chemical properties
 abundance of elements in the earth’s crust
 energy, work, forms of energy (mechanical, electrical, chemical, light, etc.)
 Temperature scales: Celsius, Kelvin, absolute zero
 calorimeter, specific heat, conductor, insulator
 potential energy, kinetic energy
 Kinetic Theory of Heat, temperature = average Kinetic Energy
 Kinetic Theory: solid, liquid gas
 electrostatic force, electric current, electrically neutral, electrical conductor
Problems:
1. What is the density of this rectangular solid with a mass of 234 g?
4.8 cm
10.5 cm
7.2 cm
2. What is the density of a cylinder with a mass of 98.45g if you insert it in 25.0mL of water and it raises the
level of the water to 35.4 mL?
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3. What mass of iron (D = 7.87 g/mL) would displace 34.0 cm of water?
4. What is the volume of a 62.9g piece of magnesium (D = 1.38 g/mL)?
5. Using the following data regarding the density of 3 liquids:
L
iq
u
id
A
B
C
V
olu
m
e
48.5m
L
12.8m
L
64.7m
L
M
ass
37.2g
174.1g
71.2g
Calculate the density of each liquid. Then assume they were placed in a cylinder, and show what order,
top to bottom, they would settle into.
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6. Perform the following conversions:
a. 41.2 kJ = ? J
b. 816 J = ? cal
7. Perform the following conversions:
o
o
a. 71 F = ? C
b. 132 C = ? K
o
c. 0.0482 kJ = ? cal
o
c. 255 K = ? C
o
8. How much heat is required to raise the temperature of 23.5 g of copper (c = 0.387 J/g C) from 250K to
298K?
9. What is the specific heat (in J/goC) of an unknown substance if adding 0.124 kJ of heat to 10θg of the substance
o
causes the temperature to increase by 12 C?
o
10. How much heat is absorbed by 100.0 mL of water if its temperature increased by 13.2 C?
o
11. If 15.00g of water at an initial temperature of 19 C absorbs 2.03 kJ of heat, what will its final temperature
be?
o
o
12. If you place 50.00g of a metal at a temperature of 98.0 C into 100.0mL of water at 22.3 C, and stir the mixture,
o
o
what is the specific heat of the lead if the final temperature of the mixture is 29.7 C? (answer in J/g C)
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Atomic Theory
Good things to know:
 Dalton’ Atomic Theory, Law of Constant Composition, Law of Definite Proportions
 Cathode Ray Tube, Thomson, electron, “plum pudding” model
 Rutherford, Gold Foil Experiment, nucleus
 Bohr, ground state, excited state, bright line spectrum, flame tests
 Chadwick, neutron
 Heisenberg’s Uncertainty Principle, Charge Cloud Model, orbital (shapes of orbitals)
 atomic number, mass number, atomic mass, isotope, ion, charge
 proton, neutron, electron – know their relative mass and charge
Problems:
1. How many protons, neutrons, and electrons are there in:
a.
238
92
U
b.
22
11
Na 1
c.
32
16
S 2
d. silver-108
e. Argon-40
2. Give the orbital diagram for:
a. carbon
b. magnesium
3. Give the electron configuration for:
a. aluminum
b. rhodium
c. tungsten
d. iodine
e. neon
f. dysprosium
4. What is the atomic mass of an element with the following isotopes:
- Bromine-79 25.34%, Bromine-80 50.00%, Bromine-81 24.66%
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The Periodic Table
Good things to know:
 Pre-periodic table patterns: Newland’s Law of Octaves, Dobereiner’s Triads
 Mendeleev’s Periodic table (based on atomic mass), holes in his table
 Moseley, atomic number, protons, Modern Periodic Law
 basic characteristics and names of the major groups
 metals, nonmetals, metalloids – “staircase”
 ionization energy, electronegativity, atomic radius, trends shown in these properties on the periodic table
Problems:
1. Give the number of valence electrons, physical state (metal, nonmetal, or metalloid), and family name for the
following:
a. aluminum
b. rhodium
c. tungsten
d. iodine
e. neon
f. dysprosium
Nomenclature
Good things to know:
 ionic compound, molecular compound, acid
Problems:
1. Give the name for the following compounds:
a. NaOH
b. CO2
c. AgCl
d. HCl
e. (NH4)2SO4
f. HgO
g. FeCl3
h. H2SO4
i. N2O5
2. Give the formulas for the following compounds:
a. lithium oxide
b. hydrosulfuric acid
c. calcium hydroxide
d. iron(III) oxide
e. lead (II) sulfide
f. copper(II) sulfate
g. carbonic acid
h. potassium oxalate
i. nitrogen monoxide
j. sodium phosphate
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Chemical Equations
Good things to know:
 5 types of reactions: synthesis, decomposition, single replacement, double replacement, combustion
 monatomic and diatomic elements
 reactant, product, precipitate, know your solubility rules
 net ionic equation, spectator ion
Problems:
1. Name the reaction type and balance:
______________ a. ____ C6H6(l) + ____ O2(g)  ____ CO2(g) + ____ H2O(l)
______________ b. ____ K3PO4(aq) + ____ Ba(NO3)2(aq)  ____ KNO3(aq) + ____ Ba3(PO4)2(s)
______________ c. ____ KClO3(s)  ____ KCl(s) + ____ O2(g)
_____XXX_____ d. ____ FeS2(s) + ____ O2(g)  ____ Fe2O3(s) + ____ SO2(g)
2. Complete the following reactions by giving the correct formulas for the products (there is no need to balance):
a. P2O5 
b. Al + O2 
c. AgNO3(aq) + NaOH(aq) 
d. LiNO3(aq) + Na3PO4(aq) 
e. Ag + NaCl 
f. Al + CuSO4 
g. Li2CO3 (aq) + Pb(C2H3O2)2 (aq) 
h.
C5H12(l) + O2 
3) Give the net ionic equation for the following reactions from #2:
c)
f)
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Stoichiometry
Good things to know:



standard temperature and pressure (STP)
Avogadro’s Number, mole
atom, formula unit, molecule
Problems:
1. What is the formula mass of :
a. CH4
b. C6H12O6
c. Mg(ClO3)2
2. What is the mass of 7.03 moles of silver carbonate?
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3. How many liters of space are occupied by 2.33 x 10 molecules of methane (CH4) gas at STP?
4. How many atoms are there in 10.3g of silver?
5. What is the percent composition of :
a. CO2
b. CuSO4
6. If you have 20.0g of a compound which is composed of 16.6g of potassium and 3.40g of oxygen,
what is the empirical formula?
7. If you have a compound which is composed of 43.7% phosphorus and 56.3% oxygen, and has a formula
mass of 284 g/mol, what is the empirical formula? What is the molecular formula?
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8. Use the following equation:
C6H12O6(s) + 6 O2(g)  6 CO2(g) + 6 H2O(l)
a. How many moles of carbon dioxide will you get if you begin with 2.50 mol of glucose?
b. How many liters of oxygen gas are needed to produce 0.430 mol of water at STP?
c. How many grams of water would you expect if you began with 15.0g of glucose?
d. How many liters of carbon dioxide would you expect if you began with 15.0g of glucose at STP?
9. 3 Fe(s) + 4 H2O(l)  Fe3O4(s) + 4 H2(g)
If you begin with 30.0g of iron and 25.0g of water:
a. What is the limiting reactant? What is the excess reactant?
b. How many grams of iron oxide and liters of hydrogen gas do you expect?
c. How many grams of the excess reactant will be left over?
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Bonding
Good things to know:
 Lewis Structures for atoms, ions, and molecular (covalent) compounds
 shared pair of electrons, unshared pair, single bond, double bond, triple bond
 VSEPR Theory, hybrid orbitals, shapes of molecules, sigma bonds, pi bonds, polarity
 Intermolecular Forces (in order from weakest to strongest): London Dispersion Forces, dipole-dipole
interactions, H-bonding, ionic bonding, covalent networks  what substances fit theses groups
 metallic bonding: why are metals solids, but good conductors of heat and electricity?
 alkane, alkene, alkyne, saturated, unsaturated hydrocarbons
 IUPAC nomenclature (know your prefixes), polymer
Problems:
1. For each of the following, give the Lewis Structure, shape, hybrid orbital type, sigma & pi bonds, and polarity:
-
a. CO2
e. NO3
b. NH3
f. NH4
c. CCl4
g. F
d. CH2O
h. MgCl2
+
-
2. Give the Lewis structure and sigma & pi bonds for the following:
a. CH3CH2CH3
c. CH3COCH3
b. SeF4
d. C5H12 (3 isomers)
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3. Using bond energies , estimate the total energy change (H) in the following reactions:
a. C2H2 + 2 H2  C2H6
b. Cl2 + C2H4  C2H4Cl2
4. Give the structure for the following compounds:
a. 2-methyl butane
b. propene
c. 2,4 – dimethyl pentane
Phases of Matter
Good things to know;
 solid, liquid, gas - Kinetic Theory of Phases; fluid
 pressure - barometer, manometer, standard pressure
 boiling, melting, freezing, condensation, evaporation, sublimation, deposition
 vaporization - evaporation vs. boiling
 hydrate, anhydrous, dessicant, deliquescent substance
 crystal lattice, viscosity
o
 density of solids, liquids, and gases; density of water at 4 C
 heats of: vaporization, fusion, crystallization, condensation
 phase diagrams - triple point, critical temperature, unique properties of water
Problems:
1. Solve the following pressure unit conversions:
a. 355 kPa = ? atm
b. 1022 Torr = ? kPa
2. What is the pressure of a 712 N object resting on a rectangular area 0.55 m x 0.025 m?
3. What is the pressure exerted by the gas?
a.
P = 743 mm Hg
45 mm
b.
P = 103.2 kPa
203 mm
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4. How much heat is required to melt 50.0g of ice at its freezing point?
5. How much heat is lost when 200.0g of steam condenses at its boiling point?
o
o
6. How much heat is required to change 50.0g of ice at -20.0 C to steam at 150 C?
The Gas Laws
Good things to know:
 Kinetic Theory of Gases
 directly proportional, inversely proportional
 5 assumptions for Ideal Gases - conditions in which ideal behavior is not exhibited
 Standard Temperature and Pressure (STP)
Problems:
1. If you have 35.0 mL of a gas in a closed container under 1.23 atm of pressure, what will the volume be if the
pressure is increased to 3.00 atm with no change in temperature?
2. If you have a 1.50L container at room temperature, what will the volume be if you place it in some boiling
water with no change in pressure?
3
o
3. If you have a 2.75dm balloon under 455kPa of pressure at 100 C, what will the volume be at STP?
4. If you have a container with a mixture of nitrogen and oxygen gases showing 1023 Torr of pressure, and
the pressure of the nitrogen alone is 544 Torr, what is the pressure of oxygen gas?
o
5. If I have 2.43 mol of gas at 35.0 C and a pressure of 789 Torr, what volume will it occupy?
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6. What is the relative rate of helium (He) gas vs. chlorine (Cl2) gas? Which one diffuses faster?
7. What volume (in L) of oxygen gas would you collect at 755 mmHg of atmospheric pressure and a room
temperature of 22oC if you decomposed 5.00g of potassium chlorate via the following reaction:
*NOTE: The vapor pressure of water at 22oC is 2 mmHg
2 KClO3(s)  2 KCl(s) + 3 O2(g)
Solutions
Good things to know:
 mixtures (how are they different from substances?), solution, solvent, solute, 5 properties of solutions
 saturated, unsaturated, supersaturated, concentrated, dilute solutions
 examples of: gas, solid in liquid, liquid in liquid, gas in liquid, and solid solutions
 Kinetic Theory of solutions (“pirhana and cow theory”)
 factors affecting solution rate: temperature, pressure(gases), surface area, stirring
 factors affecting solubility: temperature, nature of solute and solvent, pressure(gases)
 tincture, alloy, aqueous solution, colloid, suspension, emulsion
 “like dissolves like”, solubility curve
 colligative properties - antifreeze
Problems:
1. What is the molarity of a solution in which you dissolve 5.22 mol of NaCl into a 3.00L solution?
2. What is the molarity of a solution in which you dissolve 40.0g of NaCl into a 0.500L solution?
3
3. What is the molarity of a gas solution which contains 32.0L of HCl gas in a 3.44 dm container? Assume
the solution is produced at standard temperature and pressure (STP).
4. How many grams of silver sulfate (Ag2SO4) are needed to make 2.00L of a 0.0220M solution?
5. If you dilute 50.0 mL of a 6.00M HCl solution to 400.0 mL, what will the new concentration be?
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6. What is the concentration (in ppm) of a solution in which you dissolve 1.00 mg of NaCl in 300 mL of water?
7. What is the percent by mass of a solution in which 30.0g of NaCl is dissolved in 250.0 mL of water?
8. Use the solubility chart below to answer the following:
a. How many grams of KNO3
can be dissolved in 100g of water at
o
o
20 C and 60 C?
b. Which of the following is
o
most soluble at 20 C: KNO3, NaCl,
KClO3, or NH3? Which is most soluble
o
at 50 C?
c. How many grams of
potassium nitrate can be dissolved in
o
150.0g of water at 50 C?
d. If you put 50.0g of potassium
o
nitrate in 100g of water at 40 C, is the
solution saturated, unsaturated,
or supersaturated? How much is left
over?
o
e. What is the molarity of a saturated NaNO3 solution at 50 C?
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Chemical Kinetics & Thermodynamics
Good things to know:
 collision theory - collision effectiveness, collision frequency
 4 factors that affect reaction rate
 intermediate, activated complex, activation energy, heat of reaction (H) - exothermic vs. endothermic
 reaction mechanism, overall reaction, rate-determining step
 rate laws, k, general rate law
 enthalpy (H) - exothermic vs. endothermic
 entropy (S) - disordered vs. ordered
 Gibbs’ Free Energy (G) - spontaneous vs. nonspontaneous
Problems:
1. For the following reaction mechanism:
H 2O 2 + I
 HOI + OH
-
OH + H
+
+
 H2O
(slow)
(fast)
-
HOI + H + I  I2 + H2O
(fast)
a. What is the overall reaction?
b. What is the rate-determining step?
c. Name any intermediates. Are there any catalysts?
d. What is the effect of :
i. increasing the concentration of hydrogen ions?
ii. decreasing the iodide concentration?
e. Write the rate law for this reaction. What order is it?
2. Observe the following data from a rate study for the reaction:
Trial
1
2
3
4
5
6
7
8
Initial [A]
0.166
0.332
0.498
0.664
0.166
0.332
0.166
0.332
Initial [B]
0.100
0.100
0.100
0.100
0.200
0.200
0.400
0.400
A+B  C+D
Initial Rate (M/s)
4.28 x 10-6
8.56 x 10-6
1.28 x 10-5
1.71 x 10-5
3.42 x 10-5
6.85 x 10-5
2.74 x 10-4
5.48 x 10-4
a. Find the rate law for this reaction. What is the overall order of this reaction? in A? in B?
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b. Find k for this reaction.
c. If [A] = 0.500 M, and [B] = 0.500M, what would the initial rate be for the reaction?
-3
d. What concentration of B would you need if the initial rate were 3.06 x 10 M/s, and [A] = 0.650 M?
3. How much heat is given off when 4.55 g of carbon monoxide (CO) is formed from its elements?
o
o
o
4. For each of the following find H , S , G and state if the reaction is exothermic or endothermic;
favors more or less disorder; and is spontaneous or nonspontaneous:
* Assume that all of these reactions occur at room temperature (298K)
a. 4 NH3(g) + 7 O2(g)  4 NO2(g) + 6 H2O(g)
b. 4 NO2(g) + O2(g)  2 N2O5(g)
Equilibrium
Good things to know:
 characteristics of chemical equilibrium
 equilibrium constants (Keq, Ksp, Ka), mass-action expression


dissociation equation, solubility product expression, molar solubility
Le Chatlier’s Principle
Problems:
1. For the following equilibrium: N2(g) + 3 H2(g)
a. give the mass-action expression
2 NH3(g)
H = -92.6 kJ
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b. If you have 1.50 mol of nitrogen, 2.00 mol of hydrogen and 0.230 mol of ammonia gases in a 3.50 L
container, what are the concentrations of the gases?
c. Using your results from (b), what is the equilibrium constant? Does this favor the products or the
reactants?
d. If, at equilibrium, the constant is 0.0243, and the concentrations of nitrogen and hydrogen are
1.02M and 2.31M, respectively, what is the concentration of ammonia?
e. What happens to [H2] and [NH3] if you increase the concentration of nitrogen?
f. What happens to [H2] and [N2] if you decrease the concentration of ammonia (NH3)?
g. What happens to the concentrations of all the species if you raise the temperature?
h. What happens to the concentrations of all the species if you increase the pressure?
i. What happens to the concentrations of all the species if a platinum catalyst is added?
2. For each of the following, give the dissociation equation, solubility product expression, and the molar
solubility:
a. silver chloride
b. silver sulfate
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Acids and Bases
Good things to know:
 Arrhenius definitions of acid and base
 Lowry-Bronsted definitions of acid and base
 5 properties of acids and bases
 salts, electrolyte, nonelectrolyte
 ionization vs. dissociation
 self-ionization of water, pH, pOH, what is acidic and basic on each scale
 buffers, common-ion effect
 titration
Problems:
1. Identify each of the following as Arrhenius (A)cid, Arrhenius (B)ase, (S)alt, or (N)either:
a. NaCl
b. H2SO4
c. KOH
d. NH4Cl
e. Ba(OH)2
f. K3PO4
g. CH4
h. Al2(SO4)3
i. HBr
j. CO2
2. Complete and balance the following dissociation equations:
a. NaOH(s) 
b. Ba(OH)2(s) 
3. Complete and balance the following ionization equations:
a. HCl(aq) 
b. H3PO4(l) 
4. Complete and balance the following neutralization equations:
a. HCl(aq) + NaOH(aq) 
b. H2SO4(aq) + KOH(aq) 
+
5. What is the concentration of hydrogen ions [H ] in a:
a. solution with a pH of 3.54
b. 0.500M HF solution
c. solution in which concentration of hydroxide = 0.00120M
6. For each of the following Lowry-Bronsted reactions:
- name the acids and bases
- list the conjugate pairs
- name any amphoteric substances
-
+
a. HCl(aq) + H2O(l)
Cl (aq) + H3O (aq)
b. NH3(aq) + H2O(l)
NH4 (aq) + OH (aq)
+
-2
c. H2SO4(aq) + CO3 (aq)
-
-
-
HSO4 (aq) + HCO3 (aq)
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7. What is the pH for a solution in which:
a. [HCl] = 2.00 M
b. [HC2H3O2] = 2.00 M
c. pOH = 2.05
d. you dissolve 3.54L of HCl gas in 3.00 L of water
e. you dissolve 0.0325g of NaOH in 0.500 L of water
8. What is the pOH for a solution in which:
a. [OH-] = 0.012M
b. concentration of hydrogen = 0.00435M
c. pH = 7.93
9. If you have 500 mL of a 6.00M HCl solution, how much water must be added to make it 1.50M HCl ?
10. If you titrate 50.0mL of an unknown solution of HCl with 35.4mL of 0.600M NaOH, what is the concentration of the acid?
11. If you titrate 35 drops of vinegar to the equivalence point with 43 drops of 0.600M NaOH, what is the
concentration of the vinegar?
12. Rank the following acids from weakest to strongest: HCN, H 2SO4, HC2H3O2, HNO2, HF, HCl
19
Redox Reactions
Good things to know:
 what types of reactions are redox reactions
 oxidation, reduction, oxidizing agent, reducing agent
 oxidation number
 galvanic cell, cathode, anode, direction of electron flow
 types of batteries and how they work
Problems:
1. Give the oxidation number for all the elements in the following:
a. O2
b. Na2S
c. CO2
e. K2SO4
f. KClO3
g. CrO4
d. NaNO2
-2
h. Cr2O7
-2
2. Balance the following reactions. Assume they are in acidic solution. Name the oxidizing agent and reducing
agent:
-
+2
a)
____ Cu + ____ NO3  ____ Cu + ____ NO2
b)
____ NO2 + ____ ClO  ____ NO3 + ____ Cl
c)
____ TeO2 + ____ BrO3  ____ H6TeO6 + ____ Br2
-
-
-
-
3. Determine the standard potential for the following reactions. Also give the overall reaction, and identify the
cathode and anode:
a. Ni – Ni+2 / Cu – Cu+2
b. Ag – Ag+ / Zn – Zn+2
c. Al – Al+3 / Mg – Mg+2
20
Nuclear Chemistry
Good things to know:
 types of radiation: alpha particle, beta particle, neutron, proton, positron
 stability of nuclei; deviation from 1:1 ratio
 radioactive decay, nuclear disintegration, fission, fusion
 half-life
 radioactive dating, nuclear weapons, nuclear power plant
 nuclear energy - pros and cons
 rem, Curie, Bequerel
 dosimeter, Geiger Counter
Problems:
1) Complete the following nuclear equations:
a)
222
86
Rn  ______ + 42 
c)
207
82
b)
209
84
Po 
209
85
d)
1
0
At + ______
Pb + 42   ______
n +
235
92
U 
142
56
Ba + ______ + 3 01n
82
2. How much of a 3.0 g sample of Br will remain after 4.66 hours?
45
3. How long will it take for a sample of Ca to decay to 10.0% of its original mass?