Review Exercises For Third Periodical Test Limitng Reactant And Percent Yield

Review exercises for Third Periodical Test

CHEMISTRY Limiting Reactant - The reactant in a chemical reaction that limits the amount of product that can be formed. The reaction will stop when all of the limiting reactant is consumed.

Excess Reactant - The reactant in a chemical reaction that remains when a reaction stops when the limiting reactant is completely consumed. The excess reactant remains because there is nothing with which it can react. 1. Consider the chemical reaction:

NH3(g) + O2(g)

NO(g) + H2O(g)

a. If 2. 00 grams of ammonia is mixed with excess oxygen, how many grams of NO are formed? How many grams of water are formed? b. If 2. 00 grams of oxygen react with excess ammonia, how many grams of NO are formed? How many grams of water are formed? c. If 2. 00 grams of ammonia and 4. 00 grams of oxygen are combined, how many grams of NO are formed? What is the limiting reactant? What is the excess reactant? d. If 2. 00 grams of ammonia and 4. 00 grams of oxygen are combined, how many grams of water are formed? e. How much (in grams) of the other reactant is in excess? f. If the reaction actually produced just 2. 50 grams of NO, how much is the percent yield?

2. Consider the chemical reaction:

FeCl3(aq) + H2S(g)

Fe2S3(g) + HCl(g)

a. If 2. 00 grams of ferric chloride are mixed with excess hydrogen sulfide, how many grams of the ferric sulfide are formed? b. If 2. 00 grams of the hydrogen sulfide is mixed with excess ferric chloride, how many grams of the hydrochloric acid are formed? c. If 90. 0grams of ferric chloride react with 52. 0 grams of hydrogen sulfide, how much (in grams) of the HCl are formed? What is the limiting reactant? What is the excess reactant? d. If 90. 0grams of ferric chloride react with 52. 0 grams of hydrogen sulfide, how much (in grams) of the ferric sulfide are formed? e. How much (in grams) of the other reactant are in excess? f. If the reaction produced 57. 5 grams of HCl, what is the percent yield?

Answers will be given on Tuesday (12/2/2008) as we continue our review for the periodical test.