DESCRIPTION AND SAMPLE QUESTIONS FOR
UT AUSTIN TEST FOR CREDIT IN CHEMISTRY 302

The Chemistry 302 Test Covers the General Topics:

• Physical equilibria – phase transitions, solubility, colligative properties
• Chemical equilibria
• Acids and bases – definitions, weak vs. strong, pH, buffer solutions, titrations
• Electrochemistry: oxidation and reduction, electrolysis, galvanic cells, oxidation-reduction potentials
• Chemical kinetics

These topics are representative of material covered in the second semester UT Austin course for scientific and technical students. Two hours of working time is allowed. The test is multiple choice.

Textbook for CH302 Test

Although the test is not based on a specific textbook, the following book contains material that will be covered in the test: Atkins and Jones, Chapters 8-13, Chemical Principles (3rd ed.). New York: W.H. Freeman and Company, 2005. Use of a hand calculator is permitted, but it may not be shared. All programmable calculators are subject to inspection by test administrators.

These same topics are found in varying order in most general chemistry textbooks and almost any of these textbooks could be used to study for this exam.  Some other books students may find helpful:

• Whitten, Davis and Peck, General Chemistry. (6th ed.). Philadelphia: Saunders College Publishing, 2000. 
• Petrucci, Harwood, Herring, and Madura, General Chemistry. (9th ed.). New Jersey: Pearson, 2007.
• Zumdahl, Chemical Principles. (5th ed.). Boston: Houghton Mifflin Company, 2005. 

CH302 Test Practice Questions

1. The reaction for the synthesis of ammonia
            N2(g) + 3H2(g) à 2NH3(g)
      is exothermic. Increasing the temperature applied to the system
I) increases the amount of NH3.
II) decreases the amount of NH3.
III) changes the value of Keq.
IV) does not change the value of Keq.

1. I and III only
2. II and III only
3. I and IV only
4. II and IV only

2. Given the following equilibria and equilibrium constants
K1              CO(g) + H2O(g) ↔ CO2(g) + H2(g)
K2              CH4(g) + H2O(g) ↔ CO(g) + 3H2(g)
K3              CH4(g) + 2H2O(g) ↔  CO2(g) + 4 H2(g)
   The correct expression for K3 in terms of K1 and K2 is

1. K3 = K1 + K2
2. K3 = K1 - K2
3. K3 = K1 K2
4. K3 = K1 / K2
5. Cannot be determined from this information.

3. The solubility of a gas such as O2 in water (decreases, increases, stays the same) with increasing temperature.

4. For a first-order reaction, after 230 s, 33% of the reactants remain. Calculate the rate constant for the reaction.

5. For the reaction
            Zn + Cu2+ (0.100 M) à Zn2+ (0.0100 M) + Cu
the change in standard molar Gibbs free energy is -212.27 kJ/mol and the change in molar Gibbs free energy is -217.98 kJ/mol.  What is the voltage produced by the cell in which this reaction occurs with the concentrations as shown in the equation?

6. What is the H+ ion concentration in a 0.50 mol/L solution of a weak base that has an ionization constant (Kb) of 2.0 x 10-8?

7. Which is the strongest base:  ClO-, ClO3-, ClO4-, Cl-?

8. In the reaction
            B(OH)3 + H2O à B(OH)2O- + H3O+
B(OH)3 is acting as

9. Balance the redox reaction
            MnO4- (aq) + NO2- (aq) -->  MnO2(s) + NO3- (aq)
that occurs in a basic solution. What is the coefficient of MnO4 ?

10.  Given the following reaction:
            Mg(OH)2 (s) « Mg2+(aq) + 2 OH- (aq)
Increasing the pH of the solution would cause the equilibrium to shift towards the (right, left, no shift).

11. If 2.50 amperes of current are passed for 45 minutes through a solution which contains Cu2+, how many grams of Cu metal will be produced? Assume no other material is reduced in the process.

1. .9
2. 1.7
3. 2.2  
4. 2.9
5. 5.6

12.  Given the reaction
            2 NOCl (g) « 2 NO (g) + Cl2 (g)      Keq = 1.6 x 10-5
If 1 mol of NOCl is placed in a 2 L container, what is the equilibrium concentration of NO?

13.  Given the reaction
            2 NOCl (g) « 2 NO (g) + Cl2 (g)
Increasing the pressure on the system would result in an equilibrium shift to the (right, left, no shift).

• Given the following phase diagram,

           
If the triple point is at 10 atm and 10°C, what would happen if a sample of the substance at 10 atm and 5°C was kept at constant temperature and the pressure was reduced to 0.5 atm?

• Given the following experimental information for the reaction

            NH4+(aq) + NO2- (aq) à N2 (g) + 2H2O (l)
What is the rate law expression for this reaction?

• A 100 mL sample of a liquid is contained in a 500 mL closed container at 50°C.  If the temperature was increased, the vapor pressure of the liquid would (increase/decrease/stay the same).

• What is E°cell for the voltaic cell utilizing this reaction:

            Zn (s) + Cl2(g) à ZnCl2(aq)
Given: Standard reduction potentials
            Cl2 (g) + 2e- à 2 Cl- (aq)    E0 = +1.358 V
            Zn2+ (aq) + 2e- à Zn(s)      E0 = -0.763 V

• Calculate the pH of a 0.08 M HCl solution.

19. Calculate the pH of a 1.0 M HCN solution (Ka = 6.2 x 10-10).

20. Adding HF to water will have what affect on the pH?

• reduce
• increase
• no change

21. Calculate the pH of a solution containing 0.50 M CH3COOH, Ka = 1.8 x 10-5, and 0.50 M sodium acetate, NaCH3COO.

Consider the following reaction for questions 22 and 23:
            Sb + H+ + ab Sb4O6 + NO + H2O
22. What is the oxidizing agent?

1. Sb
2. H+
3.      
4. Sb4O6
5. NO

23. What is the coefficient for H+ in the balanced equation (using the set of smallest whole numbers)?

• 7
• 1
• 8
• 2
• 4     

24. Which of the following aqueous solutions, formed by mixing the two components in each case, would act as an acid-base buffer solution?

1. 100 ml of 1M HCl and 100 ml of 1M NaOH
2. 100 ml of 1M NH4Cl and 100 ml of 1M NH3       
3. 100 ml of NH3 and 100 ml of 1M HC2H3O2
4. 10 ml of 1M HCl and 100 ml of 1M NaCl

25. The solubility of M2Y3 is 1 x 10-10 mole per liter. What is the K solubility product for the compound?

1. 1 x 10-48      
2. 6 x 10-28
3. 1 x 10-20
4. 1 x 10-56

26. If the ionization constant for an acid, HA, is equal to that of a base, BOH, then the solution of the salt, BA, in water (at 25°C) is expected to have a pH

1. greater than 7.
2. equal to 7.    
3. less than 7.
4. which is impossible to predict.

27. Consider the following reaction, initially at equilibrium.
            4NH3(g) + 5O2(g) 4NO(g) + 6H2O(g)
The addition of more O2 would

1. decrease the number of moles of NH3 present. 
2. increase the number of moles of NH3 present.
3. decrease the number of moles of NO present.
4. cause no change in the number of moles of H2O present.

28. At 400°C the reaction H2(g) + I2(g) HI(g) has an equilibrium constant, Kp, of 50.00. If an equilibrium mixture of H2, I2, and HI is such that the partial pressure of H2 is 0.200 atm., and the partial pressure of I2 is 0.250 atm., the total pressure of the equilibrium mixture is:

1. 3.61 atm
2. 2.03 atm   
3. 0.45 atm
4. 32.07 atm

29. Consider a reaction which is endothermic and which is accompanied by a decrease in the randomness of the system. This reaction would           spontaneous at           temperature.

1. be, a high
2. be, a low
3. not be, a low
4. not be, a high
5. not be, any        c

30.  If the heat of formation, H°f, of CO2(g) is -94 kcal/mol while the heat of formation, H°f, of CO(g) is -26 kcal/mol, the enthalpy charge would be           for the reaction.
            2CO(g) + O2(g)CO2(g)

1. -68 kcal/mol
2. -120 kcal/mol
3. -136 kcal/mol    
4. -240 kcal/mol
5. Insufficient information given

CH302 Practice Questions Answers

1. B
2. C
3. decreases
4. 0.00482 s-1
5. 1.13 volts
6. 1.0 x 10-10 mol/L
7. ClO-
8. an acid
9. 2
10. left
11.  C
12.  2 x 10-2 M
13. left
14. it would sublime
15. Rate = (2.7 x 10-4 L mol-1 s-1) [NH4+][NO2-]
16. increase
17. 2.121 V
18. 0.1
19. –log(2.5 x 10-10)
20. B
21. 4.74
22. C
23. E
24. B
25. A
26. B
27. A
28. B
29. E
30. C