Gas Stoichiometry Worksheet Answer Key

Name: ____________________________________ Date: _________ Period: ________
Gas Stoichiometry Problems Worksheet 1
1. Given the unbalanced decomposition reaction of baking soda:
NaHCO3 (s) + heat ===> Na2CO3 (s) + CO2 (g) + HOH (g)
How many grams of each product are produced by the decomposition of 42.0 grams of
baking soda? What volumes of carbon dioxide and water are produced at STP?
2. The catalytic decomposition of hydrogen peroxide is:
H2O2 (aq) ===> H2O (l) + O2 (g)
Balance the reaction. How many moles of water and oxygen are produced by the
decomposition of 68.0 grams of hydrogen peroxide? How many molecules of water and
oxygen are produced? How many grams of each product are formed?
3. If 156.0 grams of potassium metal reacts with excess water, then how many grams of
potassium hydroxide and hydrogen gas are formed? What volume of hydrogen gas, in liters,
is formed at STP ? Be sure to balance the reaction first.
+
H2O(l)
KOH(aq) +
H2(g)
K(s)
4. Determine the number of moles of carbon dioxide gas, water, and sodium chloride formed
by the reaction of 42.0 grams of sodium bicarbonate (baking soda) reacting with excess
hydrochloric acid. The reaction is:
NaHCO3 (s) + HCl (aq) ===> CO2 (g) + HOH (l) + NaCl (aq)
Name: ____________________________________ Date: _________ Period: ________
5. The unbalanced decomposition reaction of butane gas in excess oxygen produces carbon
dioxide gas and water vapor: C4H10 (l) + O2 (g) ===> CO2 (g) + HOH (l). Starting
with 11.6 grams of butane, how many grams of carbon dioxide gas and water vapor are
formed at STP? What is the volume of these two gaseous products?
6. The burning of solid sulfur in air produces sulfur dioxide gas.
S + O2
SO2
Balance the reaction. How many moles and molecules of sulfur dioxide does the burning of
3 moles of sulfur form? Calculate the volume of sulfur dioxide produced at STP.
7. The Haber reaction produces ammonia, an important nitrogenous compound needed to
make plant fertilizers. The unbalanced reaction is: N2 (g) + H2 (g) ===> NH3 (g) +
heat. Is the reaction exothermic or endothermic ? If 170.0 grams of ammonia are
produced, then how many grams of nitrogen gas and hydrogen gas are needed? How many
molecules of each reactant are needed?
8. The unbalanced single displacement reaction between sodium metal and water is quite
violent:
Na (s) + HOH (l) ===> NaOH (aq) + H2 (g) + heat + light
If 44.8 liters of hydrogen gas are formed at STP, then how many grams of sodium and
water are needed?
Name: ____________________________________ Date: _________ Period: ________
9. Given the reaction: H2 (g) + O2 (g) ===> HOH (g). How many moles of hydrogen gas
and oxygen gas are needed to produce 11.2 liters of water vapor at STP ? How many
molecules of each reactant are needed?
10. The unbalanced synthesis reaction between aluminum metal and oxygen is:
Al (s) + O2 (g) ===> Al2O3 (s).
25
If 6.02 X 10 molecules of aluminum oxide are produced, then how many grams of
aluminum metal and oxygen gas are needed?
11. The decomposition of mercury (II) oxide to produce liquid mercury and gaseous oxygen is
shown in this unbalanced reaction:
HgO (s) + heat ===> Hg (l) + O2 (g)
How many grams of mercury (II) oxide are needed to produce 100.3 grams of liquid
mercury ? What volume of oxygen gas is formed at STP?
12. The unbalanced synthesis reaction of hydrogen gas with chlorine gas produces hydrogen
chloride gas:
H2 (g) + Cl2 (g) ===> HCl (g)
How many grams of hydrogen gas and chlorine gas are needed to produce 146.4 grams of
hydrogen chloride gas? What volumes of gaseous reactants, at STP, are needed?