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Summer Work
Grade 7
American Program
Table of Contents
Part I – Chemical Quantities ------------------------------------------------------------------- Pages 1–7
Part II – Chemical Names and Formulas ---------------------------------------------------- Pages 8–
Part III – Chemical Reactions ---------------------------------------------------------------- Pages 8–11
Part IV – Stoichiometry ---------------------------------------------------------------------- Pages 12–17
Part V – Thermochemistry ------------------------------------------------------------------ Pages 18–20
Part VI – Reaction Rates and Equilibrium ---------------------------------------------- Pages 21–24
Part I – Chemical Quantities:
Perform the following chemical quantities calculations:
1. How many moles of magnesium is 3.01 x 1022 atoms of magnesium?
2. How many molecules are there in 4.00 moles of glucose, C6H12O6?
3. How many moles are 1.20 x 1025 atoms of phosphorous?
4. How many atoms are in 0.750 moles of zinc?
5. How many molecules are in 0.400 moles of N2O5?
6. How many moles in 28 grams of CO2 ?
7. What is the mass of 5 moles of Fe2O3 ?
8. Find the number of moles of argon in 452 g of argon.
9. Find the grams in 1.26 x 10-4 mol of HC2H3O2.
10. Find the mass in 2.6 mol of lithium bromide.
11. Determine the volume in liters occupied by 14 g of nitrogen gas at STP.
12. Find the mass, in grams, of 1.00 x 1023 molecules of N2.
13. How many particles are there in 1.43 g of a molecular compound with a gram molecular
mass of 233 g?
14. Aspartame is an artificial sweetener that is 160 times sweeter than sucrose (table sugar)
when dissolved in water. It is marketed by G.D. Searle as Nutra Sweet. The molecular
formula of aspartame is C14H18N2O5 .
a) Calculate the gram-formula-mass of aspartame.
b) How many moles of molecules are in 10 g of aspartame?
c) What is the mass in grams of 1.56 moles of aspartame?
d) How many molecules are in 5 mg of aspartame?
e) How many atoms of nitrogen are in 1.2 grams of aspartame?
15. Determine the volume, in liters, occupied by 0.030 moles of a gas at STP.
16. How many moles of argon atoms are present in 11.2 L of argon gas at STP?
Second Exercise: Give the % composition of all elements in these compounds. Show all work!
1) ammonium sulfite (NH4)2SO3
2) aluminum acetate Al(C2H3O2)3
3) sodium bromide NaBr
Third Exercise:
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?
Fourth Exercise: Write the molecular formulas of the following compounds:
1. A compound with an empirical formula of C2OH4 and a molar mass of 88 g/mol.
2.
A compound with an empirical formula of CFBrO and a molar mass of 254.7 g/mol
Part II – Chemical Names and Formulas:
First Exercise: Name the following ionic and molecular compounds:
Chemical Formula
Na2S
BeO
AlN
Ag2S
MgCl2
Li2SO4
Al(ClO3)3
MgSO4
AuOH
HClO3
PBr3
CS2
PH3
NO2
CCl4
Na2SO4
Li3PO4
K2CO3
N2O
BaSO4
Zn(NO3)2
NaMnO4
Mg(OH)2
Type
Name
Second Exercise: Write the chemical formula for each of the following ionic and molecular
compounds.
Name
Calcium bromide
Beryllium fluoride
Aluminum oxide
Strontium phosphide
Aluminum nitride
Iron(III) chloride
Tin(IV) iodide
Nickel(II) phosphide
Mercury(II) oxide
Magnesium nitrate
Mercury(I) chlorate
Tin(II) phosphate
Sodium hydroxide
Carbon dioxide
Carbon sisulphide
Dichlorine monoxide
Sulfur hexafluoride
Cobalt(II) hydroxide
Type
Formula
Part III –Chemical Reactions:
First Exercise: Balance the following reactions:
1. ____ NaBr + ____ Ca(OH)2  ___ CaBr2 + ____ NaOH
2. ____ NH3+ ____ H2SO4  ____ (NH4)2SO4
3. ____ C5H9O + ____ O2  ____ CO2 + ____ H2O
4. ____ Pb + ____ H3PO4  ____ H2 + ____ Pb3(PO4)2
5. ____ Li3N + ____ NH4NO3  ___ LiNO3 + ___ (NH4)3N
6. ____ HBr + ___ Al(OH)3  ___ H2O + ___ AlBr3
Second Exercise: Indicate which type of chemical reaction (synthesis, decomposition, singledisplacement, double-displacement or combustion) is being represented in the reactions below:
1. Na3PO4 + 3 KOH  3 NaOH + K3PO4
Reaction Type _______________________
2. MgCl2 + Li2CO3  MgCO3 + 2 LiCl
Reaction Type _______________________
3. C6H12 + 9 O2  6 CO2 + 6 H2O
Reaction Type _______________________
4. Pb + FeSO4  PbSO4 + Fe
Reaction Type _______________________
5. CaCO3  CaO + CO2
Reaction Type _______________________
6. P4 + 3 O2  2 P2O3
Reaction Type _______________________
7. 2 RbNO3 + BeF2  Be(NO3)2 + 2 RbF
Reaction Type _______________________
8. 2 AgNO3 + Cu  Cu(NO3)2 + 2 Ag
Reaction Type _______________________
9. C3H6O + 4 O2  3 CO2 + 3 H2O
Reaction Type _______________________
10. 2 C5H5 + Fe  Fe(C5H5)2
Reaction Type _______________________
11. SeCl6 + O2  SeO2 + 3Cl2
Reaction Type _______________________
12. 2 MgI2 + Mn(SO3)2  2 MgSO3 + MnI4
Reaction Type _______________________
13. O3  O. + O2
Reaction Type _______________________
14. 2 NO2  2 O2 + N2
Reaction Type _______________________
Third Exercise: Writing the balanced ionic Equation, predict the products for the following
solutions are combined. Circle the precipitate (if any), place a box around the spectator ions.
a. potassium chloride(aq) + silver(I) nitrate(aq) →
b. lead (II) nitrate(aq) + hydrogen chloride(aq) →
c. sodium carbonate(aq) + potassium fluoride(aq) →
d. calcium hydroxide + sulfuric acid →
e. Li3N + NH4NO3→
f. AgNO3(aq) + CuSO4(aq) →
Part IV – Stoichiometry:
Perform the following calculations:
1. Calculate the number of grams water produced by the complete reaction of 100 g of
hydrogen with excess oxygen.
2H2 + O2 → 2H2O
2.
Calculate the mass of carbon required to consume 5.67 g of iron III oxide
+ 3C → 4Fe +3CO2
2Fe2O3
3.
Calculate the amount of oxygen in grams produced by the reaction of 69.0 g of water.
2H2 + O2
2H2O →
4.
Calculate the theoretical yield in grams of Fe produced by the reaction of 5.67 g of
iron III oxide.
+
3C
→ 4Fe +3CO2
2Fe2O3
5.
Calculate the number of moles CO2 produced by the reaction of 8.45 g of C.
+ 3C
→ 4Fe +3CO2
2Fe2O3
6.
Calculate the number of Fe atoms consumed in the reaction if 100. g of Fe2O3 react.
+ 3C + 235 KJ → 4Fe +3CO2
2Fe2O3
7. If 75.4 g of Cu is reacted with 189.7 g of I2, then CuI2 is formed.
(a)
Which reactant is in excess?
(b)
How many grams are in excess?
(c)
Calculate the amount of CuI2 produced in grams.
8.
If 15.5 g of Al are reacted with 46.7 g of Cl2, then AlCl3 is formed.
(a) Which reactant is in excess?
(b) How many grams are in excess?
(c) Calculate the amount of AlCl3 produced in moles.
9.
If 5.45g of KClO3 are decomposed to form KCl and 1.95g of O2 are collected. Calculate
the theoretical and percent yield.
10.
Calculate the volume of F2 gas at STP produced by the electrolysis of 8.2 g of KF.
2KF
→
2K +
F2
11.
Calculate the mass of KF required to produce 100 L of F2 gas at STP.
2KF → 2K + F2
12.
Calculate the actual yield in grams of Fe produced by the reaction of 0.22 Kg of C
assuming a 85.0% yield.
+
3C →
4Fe +
3CO2
2Fe2O3
13.
Calculate the number of moles of NaOH that are needed to react with 500.0 g of H2SO4
according to the following equation:
H2SO4 + 2 NaOH  Na2SO4 + 2 H2O
14. How many grams of SO2 are produced when 152 g of CS2 react with 48.0 g of O2 according
to the following equation:
CS2 + 3 O2  CO2 + 2 SO2
Part V – Thermochemistry:
First Exercise: Perform the following thermochemistry calculations:
1. How much heat will be released when 6.44 g of Sulfur reacts with excess O2 according
to the following equation?
2S + 3O2 → 2SO3
∆H° = -791.4kJ
2. How much heat will be released when 4.72 g of Carbon reacts with excess O2 according
to the following equation?
C + O2 → CO2 ∆H° = -393.5kJ
3. How much heat will be absorbed when 38.2 g of Bromine reacts with excess H2
according to the following equation?
H2 + Br2 → 2HBr
∆H° = 72.80kJ
4. How much heat will be released when 1.48 g of Chlorine reacts with excess phosphorus
according to the following equation?
2P + 5Cl2 → 2PCl5
∆H° = -886kJ
5. How much heat will be released when 4.77 g of ethanol (C2H5OH) reacts with excess O2
according to the following equation?
C2H5OH + 3O2 → 2CO2 + 3H2O
∆H° = -1366.7kJ
6. How many kilojoules of heat energy are required to heat all the aluminum (C of Al
=0.902J/g•°C) in a roll of aluminum foil (500.0 g) from room temperature (25.0 °C) to
the temperature of a hot oven (250.0 °C)?
7.
One way to cool down your cup of coffee is to plunge an ice-cold piece of aluminum into
it. Suppose you store a 20.0 g piece of aluminum (Cp of Al = .902J/g•°C) in the refrigerator at
4.40 °C and then drop it into your coffee. The coffee temperature drops from 90.0 °C to 55.0 °C.
How many joules of heat energy did the aluminum block absorb?
Second Exercise: Calculate ΔH for the reaction CO(g) + NO(g) → CO2(g) + ½ N2(g) from the
following information:
CO(g) + ½O2(g) → CO2(g) ΔH1 = -283.0 kJ
ΔH2 = 180.6 kJ
N2(g) + O2 (g) → 2NO(g)
Third Exercise: Let us consider the reaction enthalpy for the decomposition of nitroglycerine
under standard conditions.
2C3H5(NO3)3(l) → 3N2(g) + ½ O2(g) + 6CO2(g) + 5H2O(l)
ΔH°f [C3H5(NO3) 3(l)] = -364 kJ mol-1
ΔH°f [CO2(g)] = -393.5 kJ mol-1
ΔH°f [H2O(l)] = -285.8 kJ mol-1
Calculate the enthalpy change for this reaction.
Part VI – Reaction Rates and Equilibrium:
First Exercise: Fe3+(aq) + SCN-(aq)  FeSCN2+(aq)
If at equilibrium and 25°C, you have [FeSCN2+] = 0.25 mol/L, [Fe3+] = 0.046 mol/L, and
[SCN-] = 0.046 mol/L, what is the equilibrium constant, Keq?
Using the equilibrium constant you just calculated, calculate the concentration of FeSCN2+ ions
if the concentrations of Fe3+ and SCN are 0.096 mol/L each:
Second Exercise: N2 (g) + 3H2 (g)  2NH3 (g)
At 300°C, you have a 2.00L balloon filled, at equilibrium, with 0.0023 moles of N2, 0.0050 mol
of H2, and 0.00042 mol of NH3. What is the equilibrium constant?
Third Exercise: Two mole of gaseous NH3 are introduced into a 1.0 L vessel and allowed to
undergo partial decomposition at high temperature according to the reaction:
2NH3(g)  N2(g) + 3H2(g)
At equilibrium, 1.0 mole of NH3(g) remains. Keq = 0.05
What is the equilibrium [N2] and [H2]?
Fourth Exercise: The equilibrium constant for the reaction: H2(g) + I2(g) 2HI(g) is 50.
If 1.0 mol of H2 is mixed with 1.0 mol of I2 in a 0.50 L container and allowed to react at
448°C , what is the equilibrium [HI]?
Fifth Exercise: The equilibrium constant for the reaction: 2 NO (g) N2 (g) + O2 (g)
is 2.60 x 10-3 at 1100 °C.
If 0.820 mole of NO (g) and 0.223 mole each of N2 (g) and O2 (g) are mixed in a 1.00 liter
container at 1100 °C, what are the concentrations of NO (g), N2(g), and O2 (g) at equilibrium?
Sixth Exercise: A mixture of 1.16 mole of A, 1.35 mole of B and 0.641 mole of C is placed in a
one-liter container at a certain temperature. The reaction was allowed to reach equilibrium. At
equilibrium. the number of moles of A is 1.95. Calculate the equilibrium constant, Keq, for the
reaction:
2 A (g)  2 B (g) + C (g)
Seventh Exercise: What is the concentration of a saturated silver (I) acetate solution?
Ksp(AgC2H3O2) = 1.94 x 10-3.
Eighth Exercise: Which of the following salts is
i) most soluble
ii) most insoluble
CaCO3
Ksp = 4.8 x 10-9
BaCO3
Ksp = 8.1 x 10-9
MgCO3
Ksp = 1 x 10-5
SrCO3
Ksp = 1.6 x 10-9
PbCO3
Ksp = 3.3 x 10-14
Ninth Exercise: The solubility of TlCl is 0.975 g in 0.310 litres of water. Determine Ksp.