Stoichiometry

Limiting Reagents

Name: ___________________

Identify the limiting reagent and then calculate the amount of product.

1.a. Nitrogen in the cylinder of a car reacts with oxygen to produce the pollutant, nitrogen dioxide. How many moles of nitrogen dioxide are produced from the reaction of 10.0 mol of nitrogen gas with 15.0 mol of oxygen gas?

b. Identify the excess reagent and calculate the moles of this reagent.

2. An orange-brown precipitate can be produced by the reaction of ammonium hydroxide with iron (III) nitrate.

ammonium hydroxide + iron (III) nitrate ammonium nitrate + iron (III) hydroxide

a. Determine the number of moles of precipitate produced in a reaction of 10.0 mol of ammonium hydroxide with 5.0 mol of iron (III) nitrate.

b. How many moles of excess reagent are there? Calculate the mass of excess reagent.

3.a. Suppose that 100 grams of magnesium metal (24.32 g/mol) reacts with 100 grams of oxygen gas (32.00 g/mol). Calculate the mass of magnesium oxide (40.31 g/mol) which should be produced.

b. Calculate the mass of excess reagent.

4. Aluminum reacts with chlorine to produce aluminum chloride. Suppose that you have 16.0 mol of aluminum and 20.4 mol of chlorine.

2 Al (16.0 mol) + 3 Cl₂ (20.4 mol) -----> 2 AlCl₃

a. Identify the limiting reagent.

b. Use the limiting reagent to calculate the mass of product (AlCl₃) formed.

c. How many moles of excess reagent are there? How many grams?

5. Iron metal (55.85 g/mol) reacts with cupric chloride (134.45 g/mol) to produce copper metal (63.55 g/mol) and iron (II) chloride.

a. Calculate the mass of copper metal produced by a reaction of 8.50 grams of cupric chloride with 13.50 grams of iron metal.

b. Calculate the mass of excess reagent.