Supplemental Instruction
Iowa State University / Leader: / Erin Johnson
Course: / Chem 163
Instructor: / Windus/Bonaccorsi
Date: / 11/1/11
1. How many H atoms are there in 2.0158 g of H atoms?
2. Consider the unbalanced chemical equation Na + Cl2 ---à NaCl
a) Balance the equation
b) To produce one mole of NaCl from the reaction, how many grams of Na and Cl2 must you combine?
c) What is the theoretical yield in grams of NaCl from the reaction in part b?
d) You carry out the reaction and recover 45.50 g of NaCl. What is the percent yield?
3. Consider the balanced chemical equation SCl4 + 2 H2O ---à SO2 + 4 HCl
a) How many grams of H2O will react with 5.000 g of SCl4?
b) How many grams of SO2 can you make from 10.00 g of H2O?
c) Suppose you react 5.000 g of SCl4 with the amount of H2O you calculated in part a. How many grams of HCl will you form?
4. Consider the following unbalanced chemical equation P + O2 ---à P2O5
a) Balance the equation.
b) How many grams of phosphorus are required to react completely with 20.0 g of O2?
c) What is the theoretical yield in grams if you combine the amounts of reactants in part b?
5. A gaseous mixture containing 5.00 moles of H2 and 7.00 moles of Br2 reacts to form HBr.
a) Write a balanced chemical equation for this reaction.
b) Which reactant is limiting?
c) What is the theoretical yield for this reaction in moles?
d) What is the theoretical yield for this reaction in grams?
6. Sodium reacts with molecular hydrogen to form sodium hydride. A reaction mixture contains 10.0 g Na and 0.0235 g H2.
a) Write a balanced chemical equation for this reaction.
b) Which reactant is limiting?
c) What is the theoretical yield for this reaction in grams?
d) When this reaction is actually performed, 0.428 g of NaH is recovered. What is the percent yield of the reaction?
7. What is the oxidation state of the iodine atom in H2IO6^3-?
8. Pb + PbO2 + 2 H2SO4 ---à 2 PbSO4 + 2 H2O
a) Assign an oxidation state to each atom.
b) Identify the atom that gets oxidized and the atom that gets reduced.
c) Identify the reactant that is the oxidizing agent and the reactant that is the reducing agent.
9. Identify the oxidizing and reducing agents in the following reaction
(NH4)2Cr2O7 ---à N2 + Cr2O3 + 4 H2O
10. C8H18 + 25 O2 ---à 18 H2O + 16 CO2
What gets oxidized and what gets reduced?
11. 2 Cr2O7^2- + C2H5OH + 16 H^+ ---à 4 Cr^3+ + 2 CO2 + 11 H2O
Assign an oxidation state to each atom in this reaction and indicate the oxidizing agent and the reducing agent.