49 56 (8 Q's) Solutions YOU WILL SKIP THIS SECTION ENTIRELY (8 Q's) Organic Chemistry 12 none

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1 ACS Standardized Exam for CHM 122 Breakdown of Questions by Topic Question # Topic Covered Problem Set Section in ACS Book 1 12 (12 Q's) Kinetics 1, 2 Dynamics (12 Q's) Equilibrium 3, 4, 5, 6, 7 Equilibrium (12 Q's) Thermodynamics 8 Energetics (12 Q's) Electrochemistry 9 Electrochemistry and Redox (8 Q's) Solutions YOU WILL SKIP THIS SECTION ENTIRELY (8 Q's) Organic Chemistry 12 none (8 Q's) Descriptive Chemistry YOU WILL SKIP THIS SECTION ENTIRELY (8 Q's) Nuclear Chemistry 10 none TOTAL Q's THAT YOU WILL ANSWER = 64 (not 80); TIME ALLOTED = 90 min. (not 110 min)

2 1. The addition of a catalyst to a chemical system a. increases the concentration of products at equilibrium. b. increases the fraction of reactant molecules with a given kinetic energy. c. provides an alternate path with a different activation energy. d. lowers the enthalpy change in the overall reaction SO 2 (g) + O 2 (g) 2 SO 3 (g) The forward reaction is proceeding at a certain rate at some temperature and pressure; when the pressure is increased, we may expect for the forward reaction a. a greater rate of reaction and a greater yield of SO 3 at equilibrium. b. a greater rate of reaction and the same yield of SO 3 at equilibrium. c. a lesser rate of reaction and a lesser yield of SO 3 at equilibrium. d. a lesser rate of reaction and a greater yield of SO 3 at equilibrium. e. no change in rate or yield. 3. For the reaction between gaseous chlorine and nitric oxide: 2 NO(g) + Cl 2 (g) 2 NOCl(g) doubling the concentration of chlorine doubles the rate of reaction. Doubling the concentrations of both reactants increases the rate by a factor of eight. The reaction is a. first order in NO and first order in Cl 2. b. first order in NO and second order in Cl 2. c. second order in NO and second order in Cl 2. d. second order in NO and first order in Cl Which factor would cause a change in the equilibrium constant, K c for this reaction: 2 NOCl(g) 2 NO(g) + Cl 2 (g) a. adding NO(g) b. decreasing the volume of the reaction vessel c. cooling the system d. adding an inert gas 5. When the reversible reaction N 2 + O 2 2 NO has reached a state of equilibrium, a. no further reaction takes place. b. the total moles of products must equal the remaining moles of reactant. c. the addition of catalyst will cause formation of more NO. d. the concentration of each substance in the system will be constant. e. the product [N 2 ] x [O 2 ] equals [NO] 2.

3 6. Given the reaction 2 X(g) + Y(g) 2 Z(g) H = 335 kj which combination of pressure and temperature gives the highest yield of Z at equilibrium? a atm and 500 C b. 500 atm and 500 C c atm and 100 C d. 500 atm and 100 C e. catalyst, 500 atm and 100 C 7. HCl is a strong acid. What is the ph of 200 ml of M HCl? a. 2.0 b. 2.7 c. 3.4 d Which is a logical inference from the fact that a 0.10 M solution of potassium acetate, KC 2 H 3 O 2, is less alkaline than a 0.10 M solution of potassium cyanide, KCN. a. Hydrocyanic acid is a weaker acid than acetic acid. b. Hydrocyanic acid is less soluble in water than acetic acid. c. Cyanides are less soluble than acetates d. KCN ionizes to give three ions; KC 2 H 4 O 2 ionizes to give eight ions. e. Acetic acid is a weaker acid than hydrocyanic acid. 9. The addition of a small amount of acid or base will have very little effect on the ph value of a solution containing equal molar concentrations of: a. NH 4 Cl and NaCl b. NaOH and HCl c. NH 3 and NH 4 Cl d. NaOH and NaCl e. NH 3 and NaCl 10. If the concentration of a saturated solution of SrCO 3 is M, what is the value for the solubility product constant of this salt? a. 4.0 x 10-4 b. 4.0 x 10-5 c. 1.6 x 10-7 d. 1.6 x 10-9 e. 1.6 x If two salts, AX and BX 2, have the same K sp value of 4.0 x at a given temperature, then a. their molar solubilities in water are the same. b. the salts are more soluble in 0.1 M NaX than in water. c. the molar solubility of AX in water is less than that of BX 2. d. addition of NaX will not affect the solubilities of the salts.

4 12. A buffer of ph 4.1 is to be prepared from a weak acid and its salt. The best acid from which to prepare the buffer is a. phthalic acid, K 1 = 1.3 x 10-3 (first ionization) b. hydrogen phthalate, K 2 = 3.9 x 10-5 (second ionization of phthalic acid) c. benzoic acid, K = 6.3 x 10-5 d. hydrocyanic acid, K= 4 x The same quantity of electricity is passed through 1 M solutions of HCl and H 2 SO 4 at different temperatures. The number of grams of hydrogen evolved from the H 2 SO 4 solution, compared to that evolved from the HCl solution, is a. twice as much b. one half as much c. the same d. a function of the molarity of the solutions e. a function of the temperature of the solutions 14. If each of these ions were reduced to metal with one coulomb, which would yield the greatest mass? a. Cu 2+ (aq) b. Ag + (aq) c. Hg 2+ (aq) d. Cu + (aq) 15. What is true in the galvanic cell in which the overall reaction is Mg(s) + Br 2 (l) Mg 2+ (aq) + 2 Br - (aq) a. The Br 2 Br - electrode is the anode. b. Mg 2+ ions migrate towards the cathode. c. An increase in concentration of Mg 2+ would increase the cell voltage. d. The electrons enter the magnesium electrode from the external circuit. 16. Which of these salts is colored? a. Al(NO 3 ) 3 b. Ni(NO 3 ) 3 c. Ba(NO 3 ) 2 d. Sr(NO 3 ) The products of the reaction of an active metal of group IA with excess liquid water are best represented by a. MOH and H 2 b. M + (aq) and OH - (aq) and H 2 c. MOH and O 2 and H 2 d. M 2 O and H 2

5 18. Which statement is true? a. Molecular oxygen is paramagnetic b. Oxygen and ozone are isotopes c. H 2 SO 4 is called sodium sulfite d. Na 2 SO 4 is called sodium sulfite 19. Which compound is an isomer of CH 3 -CH 2 -CH 2 -OH? a. CH 3 -CH=CH-OH b. CH 3 -O-CH 2 -CH 3 c. HO-CH 2 -CH 2 -CH 3 OH d. CH H 2 C CH A product of a reaction between an alcohol and a carboxylic acid is a. an aldehyde b. a ketone c. an ether d. an ester 21. Which is the formula of an alcohol? a. CH 3 CH 2 CH 2 -O-CH 3 b. CH 3 CH 2 CH 2 -OH O c. CH 3 CH 2 CH 2 -C-H O d. CH 3 CH 2 -C-CH A radioactive atom having an atomic number of 82 and an atomic mass of 214 u loses a beta particle. The element that is the product of this nuclear change has atomic number mass number a b c d e

6 23. A sample of radioactive isotope initially contains 20 x atoms. After 16 days, 5 x atoms remain. What is the half-life of the isotope? a. 4 days b. 8 days c. 12 days d. 16 days 24. The diagram to the right represents a specific mixture of S atoms and O 2 molecules in a closed container. Circle the diagram below that shows what the container would look like after this actual mixture reaches equilibrium according to the equation below: 2 S + 3 O 2 (g) 2 SO 3 (g) K >> 1 O 2 molecule S atom (a) (b) (c) (d) (e) 25. If the systems in both beakers are at equilibrium, which salt has the smaller K sp? a. salt A b. salt B c. more information is needed T = 298 K dissolved ions solid salt A solid salt B 26. If Q > K sp in the beaker with salt C, which picture best represents what the system might look like after some time passes? dissolved ions solid salt C a. b. c. d. ANSWERS: 1. c 2. a 3. d 4. c 5. d 6. a 7. b 8. a 9. c 10. d 11. c 12. c 13. c 14. b 15. b 16. b 17. b 18. a 19. b 20. d 21. b 22. d 23. b 24. d 25. a 26. a