Quiz: Stoichiometry
Name ________________________
Show set up and work, be sure to include ALL units for credit.
1. In a spacecraft, the carbon dioxide exhaled by astronauts can be removed by its reaction
with lithium hydroxide, LiOH, according to the following chemical equation.
CO2 (g) + 2 LiOH (s) --> Li2CO3 (s) + H2O (l)
How many moles of lithium hydroxide are required to react with 20 mol of CO 2, the average
amount exhaled by a person each day?
_______________
2. In photosynthesis, plants use energy from the sun to produce glucose, C6H12O6, and
oxygen from the reaction of carbon dioxide and water. What mass, in grams, of glucose
is produced when 3.00 mol of water react with carbon dioxide?
_______________
3. What mass of carbon dioxide, in grams is needed to react with 3.00 mol of H2O in the
photosynthetic reaction described in Problem 2.
_______________
4. The first step in the industrial manufacture of nitric acid is the catalytic oxidation of
ammonia.
NH3 (g) + O2 (g) --> NO (g) + H2O (g)
(unbalanced)
The reaction is run using 824 kg of NH3, and excess oxygen.
a. How many liters of NO (g) are formed, assuming reaction occurs at STP?
_______________
b. How many molecules of water vapor are formed?
_______________
5. Tin (II) fluoride, SnF2, is used in some toothpastes. It is made by the reaction of tin with
hydrogen fluoride according to the following equation.
Sn (s) + HF (g) --> SnF2 (s) + H2 (g)
(unbalanced)
How many grams of SnF2 are produced from the reaction of 30.00 g of HF with Sn?
_______________
Quiz: Stoichiometry
KEY
Show set up and work, be sure to include ALL units for credit.
1. In a spacecraft, the carbon dioxide exhaled by astronauts can be removed by its reaction
with lithium hydroxide, LiOH, according to the following chemical equation.
CO2 (g) + 2 LiOH (s) --> Li2CO3 (s) + H2O (l)
How many moles of lithium hydroxide are required to react with 20 mol of CO 2, the average
amount exhaled by a person each day?
 2 mol LiOH 
  40 mol LiOH
x mol LiOH  20 mol CO2 
 1mol CO2 
_______________
2. In photosynthesis, plants use energy from the sun to produce glucose, C 6H12O6, and
oxygen from the reaction of carbon dioxide and water. What mass, in grams, of glucose is
produced when 3.00 mol of water react with carbon dioxide?
6 CO2 
6 H2O 
C 6H12 O 6  6 O 2
 1mol C 6H12 O 6  180 g C 6H12 O 6

x g C 6H12 O 6  3 mol H2O
 6 mol H2O  1mol C 6H12 O 6

  90 g C 6H12 O 6

_______________
3. What mass of carbon dioxide, in grams is needed to react with 3.00 mol of H 2O in the
photosynthetic reaction described in Problem 2.
6 CO2 
6 H2O 
C 6H12 O 6  6 O 2
 6 mol CO2  44 g CO2 

  132 g CO2
x g CO2  3 mol H2O
 6 mol H2O  1mol CO2 
_______________
4. The first step in the industrial manufacture of nitric acid is the catalytic oxidation of
ammonia.
4 NH3 (g) + 5 O2 (g) --> 4 NO (g) + 6 H2O (g)
(unbalanced)
The reaction is run using 824 kg of NH3, and excess oxygen.
a. How many liters of NO (g) are formed, assuming reaction occurs at STP?
 1 mol NH 3  4 mol NO  22.4 L NO 


x L NO  824,000 g NH 3 
  1, 085,741 L NO
 17 g NH 3  4 mol NH 3  1 mol NO 
1.1 10 6 L NO
_______________
b. How many molecules of water vapor are formed?
 1 mol NH 3  6 mol H2 O  6.02  10 23 molecules H2 O 



x molecules H2 O  824,000 g NH 3 

17
g
NH
4
mol
NH
1
mol
H
O
3
3
2




 4.4  10 28 molecules H2 O
_______________
5. Tin (II) fluoride, SnF2, is used in some toothpastes. It is made by the reaction of tin with
hydrogen fluoride according to the following equation.
Sn (s) + 2 HF (g) --> SnF2 (s) + H2 (g)
(unbalanced)
How many grams of SnF2 are produced from the reaction of 30.00 g of HF with Sn?
 1mol HF  1mol SnF2  156.7 g SnF2 
  117.5 g SnF2

x g SnF2  30.00 g HF

20
g
HF
2
mol
HF
1
mol
SnF




2


_______________