6.12 Aluminum reacts with chlorine gas according to the
following equation:
2Al(s) + 3Cl2(g)  2AlCl3(s)
(a) What is the mole ratio of Cl2 to Al?
(b) How many moles of Cl2 are required to react with each
mole of Al?
(c) How many moles of Cl2 are required to react with 0.085
mol of Al?
6.11 Benzene, C6H6, is a known carcinogen that burns in air
according to the following equation:
2C6H6(l) + 15O2(g) 
12CO2(g) + 6H2O(g)
(a) What is the mole ratio of O2 to C6H6?
(b) How many moles of O2 are required to react with each
mole of C6H6?
(c) How many moles of O2 are required to react with 0.38 mol
of C6H6?
6.17 The balanced equation for the decomposition of TNT,
C7H5(NO2)3, is
2 C7H5(NO2)3(s)  7C(s) + 7CO(g) + 3N2(g) + 5H2O(g)
(a) Write the mole ratios that relate moles of each product to
the reactant C7H5(NO2)3.
(b) How many moles of each product would form if 1.00 mol
of C7H5(NO2)3reacts?
(c) How many moles of each product would form if 6.25 mol
of C7H5(NO2)3react?
6.21 When active metals such as sodium are exposed to air,
they quickly form a coating of metal oxide. The balanced
equation for the reaction of sodium metal with oxygen gas is
4Na(s) + O2(g) 2Na2O(s)
Suppose a piece of sodium metal gains 2.05 g of mass after
being exposed to air. Assume that this gain can be attributed to
its reaction with oxygen.
(a) What mass of O2 reacted with the Na?
(b) What mass of Na reacted?
(c) What mass of Na2O formed?
6.24 Ethanol, used in alcoholic beverages, can be produced by
the fermentation of sucrose, which is found in sugar cane and
other plants. The balanced equation for the fermentation
process is
C12H22O11(s) + H2O(l)  4C2H5OH(l) + 4CO2(g)
(a) What mass of ethanol, C2H5OH, would be produced when
2.50 g sucrose reacts by this process?
(b) What mass of CO2 would also be produced?
6.27 Calcium carbonate, CaCO3, is often used in commercial
antacids. It acts to reduce the acidity in the stomach by
neutralizing stomach acid, which is mostly HCl, by the
following reaction:
CaCO3(s) + 2HCl(aq)  CaCl2(aq) + CO2(g) + H2O(l)
What mass of CaCO3 is needed to neutralize 0.020 mol HCl?
6.33 The balanced equation for the reaction of nitrogen and
fluorine gas to form nitrogen trifluoride is
N2(g) + 3F2(g) 2NF3(g)
What is the limiting reactant when each of the following sets of
quantities of reactants is mixed?
(a) 9 N2 molecules and 9 F2 molecules
(b) 5 N2 molecules and 20 F2 molecules
(c) 6 N2 molecules and 18 F2 molecules
6.43 The balanced equation for the reaction of nitrogen and
fluorine to form nitrogen trifluoride is
N2(g) + 3F2 (g) 2NF3 (g)
Assume that 10.0 g of N2 is mixed with 10.0 g of F2.
(a) What is the limiting reactant?
(b) What is the maximum amount of NF3, in grams, that can
be produced?
6.44 The balanced equation for the reaction of aluminum metal
and chlorine gas is
2Al(s) + 3Cl2(g) 2AlCl3(s)
Assume that 0.40 g Al is mixed with 0.60 g Cl2.
(a) What is the limiting reactant?
(b) What is the maximum amount of AlCl3, in grams, that can
be produced?
6.57 The combination reaction of sodium metal and chlorine
gas to form sodium chloride is represented by the following
balanced equation:
2Na(s) + Cl2(g)  2NaCl(s)
If 5.00 g of sodium metal reacts completely with excess chlorine
gas, and 11.5 g NaCl is actually obtained, what is the percent
yield of sodium chloride?
6.58 Ammonia is synthesized commercially from nitrogen gas
and hydrogen gas for the production of fertilizers:
N2(g) + 3H2(g)  2NH3(g)
If 100.0 g of nitrogen reacts completely with excess hydrogen,
and 34.0 g of NH3 percent yield of ammonia?
6.62 The combination reaction of sodium metal and nitrogen
gas to form sodium nitride is represented by the following
balanced equation:
6Na(s) + N2 (g)  2Na3N(s)
If 0.30 mol Na is mixed with 0.60 mol N2, and 0.092 mol Na3N is
obtained, what is the percent yield for the reaction?