Limiting Reagents II (CHEM 1405)

Back to Chemistry 1405 Practice Problems

Balance the equations, then solve for the required substance using dimensional analysis.

1. Sulfur and oxygen gas combine to form sulfur trioxide.

 

a)  If 6 moles of oxygen react with excess sulfur, how many moles of sulfur trioxide can be produced?

 

 

b)  If 40.0 g of oxygen gas and 30.0 g of sulfur react to form sulfur trioxide, which is the limiting reagent?

 

 

c)  Given the data in part b, how many grams of sulfur trioxide can be produced?

 

 

 

 

2. The hydrocarbon, CH₃OH is completely combusted.

 

a)  If 64.0 g of each reactant is provided, which one is limiting?

 

 

b)  How much water, in grams, can be produced from the reaction?

 

 

c)  How much carbon dioxide, in grams, can be produced from the reaction?

 

 

 

 

3. Magnesium metal reacts with water to form magnesium hydroxide and hydrogen gas.

 

a)  If 16.2 g of Mg reacts with 12.0 g of water, which reactant is limiting?

 

 

b)  How much of the excess reactant is left after the reaction occurs?

 

 

c)  How much magnesium hydroxide can be formed?

 

 

 

 

4. Sulfuric acid reacts with aluminum hydroxide in a double replacement reaction.

 

a)  Identify the limiting reagent if 30.0 g of sulfuric acid reacts with 25.0 g of aluminum hydroxide.

 

 

b)  How much of the excess reactant is left after the reaction occurs?

 

 

c)  How much aluminum sulfate can be formed?

 

 

d)  How much water can be formed?

 

 

 

 

5. Zinc sulfide and oxygen gas react to form zinc oxide and sulfur dioxide.

 

If 1.72 mol of zinc sulfide is reacts with 3.04 mol of oxygen gas, which reactant is limiting?

 

 

 

 

6. Aluminum metal and oxygen gas combine to form aluminum oxide.

 

a)  Which reactant is limiting if 0.32 mol of Al and 0.26 mol of oxygen gas are available?

 

 

b)  If 3.17 g of Al and 2.55 g of oxygen gas are available, how much aluminum oxide can be formed?

 

 

 

 

7. Copper II sulfide and oxygen gas react to form copper II oxide and sulfur dioxide.

 

a)  If 100 g of copper II sulfide and 56 g of oxygen are available, which reactant is limiting?

 

 

b)  What mass of copper II oxide can be formed from the reaction of 18.7 g of copper II sulfide and 12.0 g of oxygen?