Name: _________________
Date: __________________
Additional Percentage Yield and Percentage Purity Questions
1. Iron (III) oxide reacts with carbon monoxide to produce iron and carbon dioxide. If the
percentage yield is typically only 73.0%, calculate the mass of iron (III) oxide required to
produce 8.00 g of iron.
2. A sample of lead (II) nitrate is decomposed by heating and produces lead (II) oxide, nitrogen
dioxide gas, and oxygen gas. A 4.25 g sample of impure lead (II) nitrate produces 1.75 g of
PbO. Determine the percentage purity of the impure lead (II) nitrate.
3. An impure sample of sodium sulphate solution has a mass of 1.56 grams. This sample is
allowed to react with BaCl2 solution. The reaction produced 2.15 grams of barium sulphate.
Calculate the percentage purity of Na2SO4 in the original sample.
4. A sample of impure aluminum metal was treated with excess sulphuric acid. Calculate the
mass of the impure sample if a 78.0% pure sample of aluminum resulted in the production of
0.921 g of aluminum sulphate.
Additional Questions for Practice
p. 257 – 258 # 13, 19, 21, 22, 23
* You can always choose other questions from the Chapter 4 Review, the Chapter 5 Review, or
the Unit 2 Review sections for extra practice. (Answers are at the back of your textbook in
Appendix D, p. 638)