Stoichiometry Review (CHEM 1405)

Balance the equation and write the molar ratios as indicated.

1. Sn + HgNO₃ Sn(NO₃)₄ + Hg

Molar ratio of Sn to Hg __________________________ Molar ratio of HgNO₃ to Hg ___________________

Molar ratio of Sn to HgNO₃ ______________________ Molar ration of Sn to Sn(NO₃)₄ _________________

Balance each equation. Show all your work. Be sure to circle answers and check for significant figures.

2. Aluminum bromide is reacted with chlorine to produce aluminum chloride and bromine.

a) How many grams of chlorine would be produced from 35.4 grams of aluminum chloride?

b) If you produce 452 grams of bromine, how many grams of aluminum bromide did you have originally?

3. Hydrogen and nitrogen combine to yield hydrogen nitride.

a) How many grams of nitrogen would be needed to produce 17.8 grams of hydrogen nitride?

b) How many grams of hydrogen nitride are produced if you have 645 grams of nitrogen?

4. Zinc chlorate is reacted with sodium to yield sodium chlorate and zinc.

a) How many grams of zinc would be produced from 4.56 grams of sodium?

b) How many grams of zinc would be produced from 21.45 grams of zinc chlorate?

c) Based on the previous answers, which reactant is the limiting reactant?___________________________

d) When this experiment was carried out in the lab, the actual yield of zinc was 5.45 grams. What is the percent yield?

5. Aspirin (C₉H₆O₃) and water are produced when salicylic acid (C₇H₆O₃) reacts with acetic anhydride (C₄H₆O₃).

a) If 47.5 grams of salicylic acid reacts with 34.4 g of acetic anhydride, what is the limiting reagent?

b) How much of each product is produced in this reaction?

c) How much excess reagent is left over after the reaction has taken place?

d) What is the percent yield if 57.4 g of aspirin is produced?

6. Elemental copper can be produced by reacting iron (II) with copper II sulfate solution.

This experiment was carried out, the resulting copper was filtered and dried and data collected:

Mass of iron 4.20 grams

Mass of filter paper 0.67 grams

Mass of filter paper and copper 4.51 grams

a) What is the experimental (actual) yield of copper in this experiment in grams?

b) What is the theoretical yield of copper in this experiment (assuming iron is the limiting reagent)?

c) What is the percent yield in this experiment?