AP ChemistryName :

Worksheet : Ch. 13 : Obj 1-10-2Date :

A. Cumulative review :

Questions 1 –4

(A) Iron(III) hydroxide(B) Ammonia(C) Hydrofluoric acid

(D) Carbon dioxide(E) Potassium chlorate

_____ 1. Is a good oxidizing agent

_____ 2. Is used to etch glass chemically

_____ 3. Is used extensively for the production of fertilizers

_____ 4. Has amphoteric properties

_____ 5. Has both sigma and pi bonds

_____ 6. An excess of magnesium is added to 500.0 mL of 0.10M HCl at 0 ºC and 760 mm Hg. What volume of hydrogen gas will be produced?

a. 1.12 L b. 560. mL c. 2.24 L d. 280. mL e. 140. mL

_____ 7. ____Fe2+ + ____MnO4– + ____8 H+ --> ____Fe3+ + ____Mn2+ + ____H2O

According to the balanced equation above, the coefficient of the iron(II) ion is :

a. 2 b. 3 c. 5 d. 7 e. 6

Questions 8-12 refer to the following elements.

(A)Lithium

(B)Nickel

(C)Bromine

(D)Uranium

(E)Fluorine

_____ 8. Is a gas in its standard state at 298 K

_____ 9.Reacts with water to form a strong base

_____ 10. Can be oxidized by chlorine.

_____ 11. Forms colored aqueous salt solutions.

_____ 12. Has f orbitals.

_____ 13.A yellow precipitate forms when 0.5 M NaI(aq) is added to a 0.5 M solution of which of the following ions?

(A) Pb2+(aq)(B) Zn2+(aq)(C) CrO42–(aq)

(D) SO42–(aq)(E) OH–(aq)

B. Answer true or false.

_____ 1. All reactions are reversible.

_____ 2. At equilibrium, the forward and reverse rates are equal.

_____ 3. The equilibrium position of a reaction favors the side (reactants or products) with the greater entropy (assume all other factors are equal).

_____ 4. The equilibrium position of a reaction favors the side (reactants or products) with the higher enthalpy(assume all other factors are equal).

_____ 5. A change in pressure changes the concentration of a gaseous reactant or product.

_____ 6. A change in pressure will not affect the equilibrium position of a reaction which has an unequal number of moles of gases in the reactants and products.

_____ 7. A change in the concentration of a reactant or product will change the equilibrium position at a constant temperature.

______8. For a reaction at equilibrium at a certain temperature, a change in the concentration of a reactant or product will change the value of the equilibrium constant, K.

_____ 9. The value of K is independent of the concentrations (or pressure of gaseous reactants or products) of reactants or products.

_____ 10. The value of K is dependent on the stoichiometry of an equation at equilibrium.

_____ 11. The value of K is independent of the temperature at which a reaction occurs.

_____ 12. The concentration of a pure solid does not change in a chemical reaction.

_____ 13. The value of K is independent of reactants or products that are pure liquids or solids.

_____ 14. If the number of moles of gaseous reactants and gaseous products are equal, K will equal Kp.

B. Problems :

15. Write the equilibrium expression (K) for each of the following gas-phase reactions, which occur in the atmosphere:

a. NO(g) + O3(g) ↔ NO2(g) + O2(g)

b. O3(g) ↔ O2(g) + O(g)

c. Cl(g) + O3(g) ↔ C1O(g) + O2(g)

16. For which of the reactions in number 15 is Kpequal to K?

17. Write the equilibrium expression (Kp) for each reaction in no. 15 above.

a.

b.

c.

18. At a given temperature, K = 278 for the reaction 2SO2(g) + O2(g) = 2SO3(g)

Calculate values of K for the following reactions at this temperature.

a. SO2(g) + ½ O2(g) ↔ SO3(g)

b. 2SO3(g) ↔ 2SO2(g) + O2(g)

c. SO3(g) ↔ SO2(g) + ½ O2(g)

d. 4SO2(g) + 2O2(g) ↔ 4SO3(g)

19. At high temperatures, elemental nitrogen and oxygen react with each other to form nitrogen monoxide:

N2(g) + O2(g) ↔ 2NO(g)

Suppose the system is analyzed at a particular temperature, and the equilibrium concentrations are found to be [N2] = 0.041 M, [O2] = 0.0078 M, and [NO] = 4.7 X 10-4 M. Calculate the value of K for the reaction. For the reaction.

20. At a particular temperature, a 3.00-L flask contains 3.50 mol HI, 4.10 mol H2, and 0.30 mol I2 in equilibrium. Calculate K at this temperature for the reaction

H2(g) + I2(g) ↔ 2HI(g)

21. Consider the reaction 2NOCl(g) ↔ 2NO(g) + Cl2(g). At 25°C, a particular experiment had the following equilibrium pressures:

PNOCl= 1.20 atm

PNO = 1.25 x 10-2 atm

PCl2 = 3.00 x 10-1 atm

Calculate the value of Kpfor the reaction at 25°C.

22. At 127 °C, K = 2.6 x 10-5 mol2/L2 for the reaction 2NH3(g) ↔ N2(g) + 3H2(g) Calculate Kpat this temperature.

23.At 1100 K, Kp= 0.25 atm-1 for the reaction 2SO2(g) + O2(g) ↔ 2SO3(g). What is the value of K at this temperature?

24. Write expressions for K for the following reactions.

a. P4(s) + 5O2(g) ↔ P4O10(s)

b. NH4NO3(s) ↔ N2O(g) + 2H2O(g)

c. CO2(g) + NaOH(s)↔ NaHCO3(s)

d. S8(s) + 8O2(g) ↔ 8SO2(g)

25. For which reactions in number 24 above is Kpequal to K?

26. For the reaction CaCO3(s) ↔ CaO(s) + CO2(g) it is found that at equilibrium [CO2] = 2.1 x 10-3M at a particular temperature. Calculate K for the reaction at this temperature.

27. An equilibrium mixture contains 0.60 g solid carbon and the gases carbon dioxide and carbon monoxide at partial pressures of 2.9 atm and 2.6 atm, respectively. Calculate Kpfor the reaction

C(s) + CO2(g) ↔ 2CO(g)

Answers : 15a. K = [NO2][O2]/[NO[O3] 15c. K = [ClO][O2]/[Cl][O3] 16. a and c 17a. Kp = PNO2 x PO2/(PNO x PO3) 18a. 16.7 18b. 3.60 x 10-3 18c. 6.00 x 10-2 18d. 7.73 x 104 19. 6.9 x 10-4 20. 10. 21. 3.26 x 10-5 atm 22. 2.8 x 10-2 atm2 23. 23 L/mol 24a. K = 1/[O2]5 24b. k = [N2O][H2O]2 24c. K = 1/[CO2] 24d. K = [SO2]8/[O2]8 25. d only 26. K = 2.1 x 10-3 M 27. 2.3 atm