SOLVED

41) In a reaction at equilibrium involving only gases, a pressure change will shift the reaction only when: A) heat is absorbed by the reaction proceeding to the right B) the number of molecules on one side is greater than the number on the other side of the balanced equation C) the number of molecules increases during the chemical reaction D) the gases are impure E) the collision rate increases 42) Equilibrium constant K is constant except when one varies the: A) concentrations of the reactants B) temperature of the reaction C) concentration of the products D) partial pressures of the reactants E) K always remains constant 43) For the reaction; N2(g) + 3 H2(g) ? 2 NH3(g), the equilibrium amount of NH3 will be increased by: I)increasing the pressure II)adding H2  III)removing N2  IV)decreasing the pressure A) I, III B) III only C) II, III D) I, II E) II, IV 44) For the reaction: CH4(g) + 2H2O(g) ? CO2(g) + 4H2(g) ΔH° = +190 kJ add N2(g) at constant volume and: A) the reaction reacts to the right. B) the reaction reacts to the left. C) the ΔH° increases. D) the temperature increases. E) there is no change. 45) What will happen to the equilibrium in the reaction 2 A(g) ? B(g) + C(g), Kc = 1.25 at 300 K if a catalyst is added? A) The reaction is forced to the right. B) The reaction is forced to the left. C) No change, catalyst only changes the rate. D) Kc is increased. E) Kc is decreased. 46) Consider the following chemical reaction at equilibrium: 2 Cl2(g) + 2 H2O(g) ? 4 HCl(g) + O2(g) This equilibrium can be shifted to the right by: A) removing H2O(g) from the mixture. B) adding more O2(g) to the mixture. C) adding Ne(g) to the mixture. D) decreasing the volume of the mixture. E) increasing the volume of the mixture. 47) For the following reaction O2(g) ? 2O(g) what conditions favor production of oxygen atoms? A) high temperature and low pressure B) high temperature and high pressure C) low temperature and low pressure D) low temperature and high pressure 48) 0.75 mol of N2 and 1.20 mol of H2 are placed in a 3.0 liter container. When the reaction N2(g) + 3H2(g) ? 2 NH3(g) reaches equilibrium, [H2] = 0.100 M. Which of the following is true? A) [NH3] = 0.150 M B) [NH3] = 0.200 C) [N2] = 0.650 M D) [N2] = 0.250 E) [NH3] = [H2] = 0.05 M 49) 2.5 moles H2O and 100 g of C are placed in a 50-L container. At equilibrium for the reaction C(s) + H2O(g) ? CO(g) + H2(g), [H2] = 0.040 M. Which of the following is true? A) [CO] = 0.020 M B) [H2O] = 0.010 M C) no carbon is left D) [H2O] = 0.020 M E) [C(s)] = 0.04 M 50) Consider the following reaction at a certain temperature. 2SO3(g) ? 2SO2(g) + O2(g) When the initial concentration of SO3(g) is 0.128 M, the concentration of oxygen gas at equilibrium is found to be 0.0130 M. Calculate Kc for this reaction. A) 8.45 x 10-4 B) 1.62 x 10-2 C) 7.64 x 10-5 D) 1.47 x 10-3