Name __________________________________
Period _______
Stoichiometric Conversions Worksheet
Use this worksheet for:
Convert
Substance A
Moles, mass, volume, or number of particles
Substance B
Moles, mass, volume, or number of particles
Procedure:
First identify the given quantity. This will be a given amount of moles, grams, liters, or particles.
1. Convert to moles. If the given quantity is in grams, liters or particles, convert to moles.
2. Use the mole ratio from the coefficients in the balanced chemical equation to convert from
moles of the given substance to moles of the substance you need.
3. Convert moles of the substance you need to grams, liters or particles, depending on what the
question asks for.
Converting between
grams and moles: use molar mass
(add up masses from periodic table)
liters and moles of a gas at STP
particles and moles (particles are
atoms, molecules or formula units)
to moles
1 mol
XX.X g
from moles
XX.X g
mol
1 mol
22.4 L
22.4 L
mol
1 mol
6.02 x 1023 particles
6.02 x 1023 particles
mol
Example:
2C(s) + O2(g) → 2CO(g)
How many grams of oxygen gas are required to react completely with 48 g of carbon?
Step 1: How many moles is 48 grams of carbon? (convert 48 grams of carbon to moles of carbon).
given
quantity
conversion
factor
1 mol C
48 g C x 12 g C = 4.0 mol C
Step 2: Convert moles carbon to moles oxygen gas. Use coefficients from balanced equation.
1 mol O2
4.0 mol C x 2 mol C = 2.0 mol O2
Step 3: What is the mass of 2.0 moles of oxygen gas at STP? (convert moles oxygen gas to grams
oxygen gas).
32 g O2
2.0 mol O2 x mol O = 64 g O2
2
You can also perform the entire calculation in one setup.
1 mol C
1 mol O2
32 g O2
48 g C x 12.0 g C x 2 mol C x mol O = 64 g O2
2
Problems:
Set up all problems neatly and show which units cancel!
1. For the reaction 2Na + 2H2O → 2NaOH + H2, what is the volume at STP of hydrogen gas
produced when 69 grams of sodium react with water?
a. Step 1: How many moles is 69 g Na?
1 mol Na
69 g Na x 23.0 g Na = 3.0 mol Na
b. Step 2: How many moles of hydrogen gas are produced from the number of moles of sodium
calculated above?
1 mol H2
3.0 mol Na x 2 mol Na = 1.5 mol H2
c. Step 3: What is the volume at STP of hydrogen gas produced?
1.5 mol H2 x
22.4 L H2
mol H2 = 34 L H2
d. Show this calculation in one setup.
1 mol Na
1 mol H2
22.4 L H2
69 g Na x 23.0 g Na x 2 mol Na x mol H
= 34 L H2
2
2. In the reaction 3CuSO4 + 2Al → Al2(SO4)3 + 3Cu, how many moles of copper will be produced
from 2 moles of aluminum?
3 mol Cu
2 mol Al x 2 mol Al = 3 mol Cu
3. In the reaction 2FeBr3 + 3Cl2 → 2FeCl3 + 3Br2, how many moles of FeCl3 will be produced
from 6 moles of Cl2?
2 mol FeCl3
6 mol Cl2 x 3 mol Cl = 4 mol FeCl3
2
4. For the reaction of problem 3, how many grams of bromine are produced from each mole of FeBr3?
3 mol Br2
159.8 g Br2
1 mol FeBr3 x 2 mol FeBr x mol Br
= 239.7 g Br2
3
2
5. For the reaction of problem 3, how many moles of chlorine gas are required to produce 145 g of
FeCl3?
mol FeCl3
3 mol Cl2
145 g FeCl3 x 162.2 g FeCl x 2 mol FeCl = 1.34 mol Cl2
3
3
2
6. From the reaction 4Fe + 3O2 → 2Fe2O3, how many grams of iron oxide (Fe2O3) are produced
when 111 grams of iron (Fe) rusts?
1 mol Fe
2 mol Fe2O3
159.7 g Fe2O3
111 g Fe x 55.85 g Fe x 4 mole Fe x mol Fe O
= 159 g Fe2O3
2 3
7. For the reaction 3BaCl2 + 2Na3PO4 → Ba3(PO4)2 + 6NaCl, what mass of barium chloride is
needed to react completely with 46.8 g of sodium phosphate?
1 mol Na3PO4
3 mol BaCl2
208.2 g BaCl2
46.8 g Na3PO4 x 163.9 g Na PO x 2 mole Na PO x mol BaCl
= 89.2 g BaCl2
3
4
3
4
2
8. Hydrogen gas reacts with oxygen gas to form water. At STP, how many liters of hydrogen gas
react with 32.45 liter of oxygen gas?
2 L H2
32.45 L O2 x 1 L O = 64.90 L H2
2
2H2 + O2 → 2H2O
9. Lithium hydroxide (LiOH) is used in spacecraft to remove exhaled carbon dioxide from the air.
The lithium hydroxide reacts with carbon dioxide to produce lithium carbonate (Li2CO3) and water.
How many grams of carbon dioxide can be absorbed from each gram of lithium hydroxide?
2LiOH + CO2 → Li2CO3 + H2O
1 mol LiOH
1 mol CO2
44.01 g CO2
1 g LiOH x 23.9 g LiOH x 2 mol LiOH x mol CO
= 0.921 g CO2
2
10. If 3.0 L of methane gas (CH4) are burned, what volume of carbon dioxide at STP will be produced?
1 L CO2
3.0 L CH4 x 1 L CH = 3.0 L CO2
4
CH4 + 2O2 → CO2 + 2H2O
11. Given the reaction 3NO2(g) + H2O(l) → 2HNO3(aq) + NO(g), how many grams of nitric acid
(HNO3) are produced from 10.0 L of NO2?
1 mol NO2
2 mol HNO3
63.0 g HNO3
10.0 L NO2 x 22.4 L NO x 3 mol NO x mol HNO = 18.8 g HNO3
2
2
3
12. From the reaction NH3 + 2O2 → HNO3 + H2O, how many moles, grams, liters at STP, and
molecules of oxygen gas are required to react completely with 68.0 grams of ammonia (NH3)?
1 mol NH3
68.0 g NH3 x 17.0 g NH = 4.00 mol NH3
2 mol O2
4.00 mol NH3 x 1 mol NH = 8.00 mol O2
3
3
32.0 g O2
= 256 g O2
8.00 mol O2 x mol O
2
8.00 mol O2 x
22.4 L O2
mol O2 = 179. L O2
6.02 x 1023 molecules O2
= 4.82 x 1024 molecules O2
8.00 mol O2 x
mol O2
3