Stoichiometry Review

Use a periodic table, but NO calculator! Round molar masses to the "ones" place.

Fill in all the answers, written as a number, then press "Check" (bottom of the page) to check your answers.
Remember the Steps for Stoichiometry:

1. Start with a balanced equation
2. Label your Givens with A or A1 and A2
3. Label your To Finds with B or B1 and B2
4. Convert your Given A to Moles A, using the Molar Mass of A
5. Convert your Moles A to Moles B using the Mole Ratio from the Balanced Equation
6. If you are asked for Moles, stop here!
7. If you are asked for Grams, Convert Moles B to Grams B using the Molar Mass of B
8. If you are asked for Volume, use the fact that 1 mole of any gas contains 22.4 L at STP (standard conditions)!




1. In the formation of carbon dioxide from carbon monoxide and oxygen, how many moles of carbon monoxide are needed to react completely with 7.0 moles of oxygen gas?

2 CO (g) + O2(g) → 2 CO2 (g)

moles




2. How many moles of carbon dioxide, CO2, can be formed by the decomposition of 5 moles of aluminum carbonate, Al2(CO3)3?

Al2(CO3)3 → Al2O3 + 3 CO2

moles




3. In the formation of carbon dioxide from carbon monoxide and oxygen, how many liters of carbon monoxide, CO, are needed to react completely with 1/2 mole of oxygen gas at STP?

2 CO (g) + O2(g) → 2 CO2 (g)

liters




4. How many moles of oxygen are required to burn 22.4 liters of ethane gas, C2H6 at standard conditions?

2 C2H6 (g) + 7 O2(g) → 4 CO2 (g) + 6 H2O (g)

moles




5. How many grams of oxygen are produced by the decomposition of 1 mole of potassium chlorate, KClO3?

2 KClO3 → 2 KCl + 3 O2

grams




6. A chemist performs the synthesis of sodium chloride from its elements. The chemist begins with 46 grams of sodium. How many moles of chlorine are needed?
2 Na + Cl2 → 2 NaCl

moles




7. How many grams of water can be prepared from 5 moles of hydrogen at standard conditions?
2 H2 (g) + O2(g) → 2 H2O

grams




8. Suppose that an excess of propane, C3H8 burns in 320 g of O2. How many moles of H2O will be formed?
C3H8 + 5 O2 → 3 CO2 + 4 H2O

moles




9. At standard conditions, how many liters of carbon dioxide, CO2, will be formed by the combustion of 1/2 mole of propane, C3H8?
C3H8 + 5 O2 → 3 CO2 + 4 H2O

liters




10. How many grams of water can be prepared from 8 grams of hydrogen and excess oxygen at standard conditions?
2 H2 (g) + O2(g) → 2 H2O

grams