TTU General Chemistry

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Chem 111 - Quiz 3C - Fall, 1997
Chapter III: Chemical Reactions & Reactions Stoichiometry

1. Which of the following reactions is not balanced?

a) P4 + 3O2 --> P4O6
b) Cu(NO3)2 --> CuO + 2NO2 + O2
c) 2Al2O3 + 3C + 6Cl2 --> 4AlCl3 + 3CO2
d) 3PbO + 2NH3 --> 3Pb + N2 + 3H2O

2. Balance the following reaction with the simplest set of intergers: H2O + KO2 --> KOH + O2. What is the stochiometric coefficient of O2?

a) 1
b) 2
c) 3
d) 4

3. Consider the solution reaction AlCl3 + 3AgNO3 --> 3AgCl + Al(NO3)3. What volume of 0.100 M AgCl3 will exactly react with 55.0 mL of 0.162 M AgNO3?

a) 89.1 mL
b) 9.90 mL
c) 46.2 mL
d) 29.7 mL

4. What is the molarity of a solution in which 26.0 grams of BaCl2 (molar mass = 208.2 g/mol) are dissolved in enough water to make 450.0 mL of solution?

a) 0.278 M
b) 0.617 M
c) 1.00 M
d) 3.41 M

5. If the above solution has a density of 1.22 g/mL, what is the mass percent of BaCl2 in the solution?

a) 2.6%
b) 4.7%
c) 5.7%
d) 7.3%

6. Consider the reaction 2KNO3 + 10K --> 6K2O + N2. If 155 grams of K reacted with 122 grams of KNO3, what is the limiting reagent?

a) KNO3
b) K
c) neither
d) not enough information

7. Consider the reaction HgS + O2 --> SO2 + Hg. If 200.0 grams of HgS reacted with 150.0 grams of O2, what is the limiting reagent?

a) HgS
b) O2
c) neither
d) not enough information

8. Consider the reaction Cu2S + O2 --> 2Cu + SO2. If 55.0 grams of Cu2S is heted in excess O2,what is the mass of Cu that can be produced?

a) 43.9 g
b) 2.0 g
c) 18.5 g
d) 55.0 g

9. Balance the following reaction with the simplest set of intergers: Fe3O4 + H2 --> Fe + H2O. What is the stochiometric coefficient of H2?

a) 1
b) 2
c) 3
d) 4

10. Consider the reaction 2ZnS + 3O2 --> 2ZnO + 2SO2. Suppose that you wanted enough O2 to completely react with 500. g of ZnS. What mass of O2 should be present?

a) 164 g
b) 110. g
c) 215 g
d) 246 g

11. Fe can be prepared as 2Al + Fe2O3 --> 2Fe + Al2O3. Suppose that 0.450 moles of Fe2O3 are reacted with an excess of Al. Suppose that 43.6 grams of Fe are obtained. What is the percent yield of Fe?

a) 16.2%
b) 60.7%
c) 86.7%
d) 43.4%

12. 25.0 mL of a 0.175 M solution of KOH is diluted with pure water to a final volume of 750.0 mL. What is the final molarity of the KOH solution?

a) 0.00583 M
b) 0.0163 M
c) 0.0333 M
d) 0.229 M

KEY

1)b 2)c 3)d 4)a 5)b 6)b 7)a 8)a 9)d 10)d 11)c 12)a