Name_______________________________________
Hands on Study Guide – this was the unit test from a prior year!! Try it!!
Stoichiometry Unit Test: Mixed Stoichiometric/Limiting Reagent/Percent Yield Problem Solving
Unit Test will cover:
1. Stoichiometric conversion from:
Moles to moles
a. Moles to grams
b. Grams to moles
c. Grams to Grams
2. Be able to calculate percent yield when given actual yield and theoretical yield (
Percent Yield =( actual yield/theoretical yield) x 100
3. Be able to determine the limiting reactant
(I)
Mixed Stoichiometric Problem Solving: Solve the following problems show all work and units for full credit,
round the answer to one decimal place (e.g. 45.6 or 7.2 or 0.3). Total 40 pts.
1) Solve the problems based on the equation below:
2 KClO3(s)  2 KCl(s) + 3 O2(g)
(a) Calculate the mass of oxygen (O2) produced from the decomposition of 55 g of potassium chlorate (KClO3).
(5 pts)
(b) Calculate the mass of potassium chloride (KCl) produced from the decomposition of 75 g of potassium
chlorate (KClO3) (5 pts)
2) Use the equation below to solve the following problems:
2 Al + 3 ZnCl2  3 Zn + 2 AlCl3
(a) How many moles of Zn would result from 2.5 moles of Al? (5 pts)
(b) How many grams of AlCl3 would result from 6.5 moles of ZnCl2? (5 pts)
3) Aluminum reacts with oxygen to give aluminum oxide, as show in the chemical equation below:
4 Al(s) + 3 O2 (g)  2 Al2O3(s)
(a) What amount of O2 in liters is needed for complete reaction with 6 moles of Al? (5 pts)
(b) What amount of Al2O3 in grams can be produced can be produced with 125 grams of O2? (5
pts)
Name_______________________________________
Hands on Study Guide – this was the unit test from a prior year!! Try it!!
Stoichiometry Unit Test: Mixed Stoichiometric/Limiting Reagent/Percent Yield Problem Solving
4) Based on the following reaction answer the questions below:
Al(OH)3(s) + 3 HCl(aq)  AlCl3(aq) + 3 H2O(l)
(a) What mass of HCl, in grams, is required to react with 75 grams of Al(OH)3? (5 pts.)
(b) What mass of water (H2O), in grams is produced? (5 pts.)
(II)
Limiting Reactant &Percent Yield (60 pts)
5) Aluminum chloride, AlCl3, is made by treating scrap aluminum with chlorine, this reaction is shown below, if you
begin with 2.7 g of Al and 6.5 g of Cl2
2 Al (s) + 3 Cl2 (g)  2 AlCl3 (s)
(a) Which reactant is the limiting reactant? Show all work for full credit. (15 pts)
(b) What is the maximum mass of AlCl3 can be produced based on the given information above? (15 pts)
(c) What mass of the excess reactant remains when the reaction is completed? (15 pts)
(d) If a chemist makes 6.6 g AlCl3 in the laboratory what is the percent yield?(15 pts)