TTU General Chemistry

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

1. Which of the following represents the correct way to prepare a 1M solution of sodium chloride, NaCl?

a) Dissolve 5.8g of NaCl in water and dilute to a total of 100 mL.
b) Dissolve 58g of NaCl in 1.0 L of water.
c) Dissolve 58g of NaCl in 100 g of water.
d) Dissolve 58g of NaCl in 942 mL of water.
e) Dissolve 100g NaCl in water and then dilute to a total of 100 mL.

2. Which of the following equations is not balanced?

a) Zn + 2HCl --> ZnCl2 + H2
b) 2Na + 2H2O --> 2NaOH + H2
c) CH4 + 2O2 --> CO2 + 2H2O
d) 2H2 + O2 --> 2H2O
e) SO2 + O2 --> SO3

3. Determine the molarity of a 70% perchloric acid, HClO4, solution which has a density of 1.67 g/mL.

a) 11.7 M
b) 2.4 M
c) 0.42 M
d) 8.5 M
e) 16.7 M

4. What is the molarity of a sulfurous acid (H2SO3) solution if 23.7 mL of this solution requires 16.8 mL of 0.296 M NaOH for titration to the end point?

H2SO3 + NaOH --> Na2SO3 + 2H2O

a) 0.0625 M
b) 0.210 M
c) 0.358 M
d) 0.105 M
e) 0.421 M

5. What mass of CaCO3 is required to react with 100 mL of 2.0 M HCl solution?

CaCO3 + 2HCl --> CaCl2 + CO2 + H2O

a) 40.0 g
b) 5.00 g
c) 10.0 g
d) 15.0 g
e) 20.0 g

6. What volume of 1.50 M NaOH is required to prepare 300 mL of 0.200 M NaOH?

a) 0.100 mL
b) 2.25 mL
c) 10.0 mL
d) 40.0 mL
e) 1.00 mL

7. What is the molarity of a solution that contains 70.0 g of H2SO4 in 280 mL of solution?

a) 11.8 M
b) 2.55 M
c) 6.84 M
d) 8.62 M
e) 9.78 M

8. What mass of AgNO3 is required to prepare 800g of a 3.50% solution?

a) 28.0 g
b) 24.6g
c) 26.7g
d) 27.0g
e) 25.5g

9. The reaction of 5.0 g of F2 with excess Cl2 produced 5.6g of ClF3. What is the percent yield of the reaction?

Cl2 + 3F2 --> 2ClF3

a) 92%
b) 58%
c) 69%
d) 76%
e) 86%

For questions 10-13, use the following equation.

SiO2 + 4HF --> SiF4 + 2H2O

10. What mass of SiF4 can be prepared from the reaction of 15g SiO2 with excess HF?

a) 52g
b) 1.04g
c) 12g
d) 26g
e) 104g

11. If 5.0g of SiO2 is reacted with 6.0g of HF, the limiting reagent is:

a) H2O
b) SiO2
c) HF
d) SiF4

12. Given the data from question 11, the theoretical yield of H2O is:

a) 2.7g
b) 7.8g
c) 8.7g
d) 3.0g
e) 11g

13. Given the data from question 11, which of the following is true when the reaction is completed?

a) 0.50g of HF remains unreacted
b) 0.67g of SiO2 remains unreacted
c) 0.67g of HF remains unreacted
d) 0.50g of SiO2 remains unreacted

14. When balanced, the sum of the following coefficients is:

SnS2 + HCl --> H2SnCl6 + H2S

a) 13
b) 4
c) 6
d) 7
e) 10

15. Based on the following balanced equation, how many molecules of O2 would react with 56 molecules of C2H6?

2C2H6 + 7O2 --> 4CO2 + 6H2O

a) 784
b) 196
c) 392
d) 112
e) 50

KEY

1)a 2)e 3)a 4)d 5)c 6)d 7)b 8)a 9)c 10)d 11)c 12)a 13)d 14)e 15)b