SOLVED

71) Find Kp for the following reaction at 25.0°C. SbCl5(g) ? SbCl3(g) + Cl2(g)Kc = 2.51 × 10-2 A) 0.614 B) 1.03 × 10-3 C) 5.15 × 10-2 D) 9.74 × 102 E) 39.8 72) For a reaction, the reaction quotient, Qc > Kc, the reaction ________. A) is at equilibrium B) is exothermic C) shifts to the right D) shifts to the left E) is endothermic 73) For the reaction: 2 SO2(g) + O2(g) ? 2 SO3(g), Kc = 6.9 × 1024 at 25°C. If a reaction vessel is filled with these gases, such that [SO2] = 6.0 M, [O2] = 6.0 M and [SO3] = 6.0 M, in which direction will the reaction proceed? A) The reaction proceeds to the right. B) The reaction proceeds to the left. C) The reaction is already at equilibrium. D) The reaction volume must be specified to answer this question. E) The value of Kp must be specified to answer this question. 74) For the reaction: 2 Cl2(g) + 2 H2O(g) ? 4 HCl(g) + O2(g), Kp = 6.4 × 10-6 at 500 K. If a fixed volume is filled with initial concentrations of these gases at 227°C such that [Cl2] = 0.5 M, [H2O] = 0.40 M, [HCl] = 0.5 M, and [O2] = 0.015 M, in which direction will the reaction proceed? A) The reaction proceeds to the right. B) The reaction proceeds to the left. C) The reaction is already at equilibrium. D) The reaction volume must be specified to answer this question. E) The value of Kp at 25 °C must be specified to answer this question. 75) For the reaction 2 A(g) ? B(g) + C(g), Kc = 1.25 at 300 K. If a 1.00 L mixture contains 0.619 mol A, 0.693 mol B, and 0.689 mol C at 300 K, will the mixture be in equilibrium? If not, in what direction will a net reaction occur? A) Yes, at equilibrium. B) No, net reaction to the left. C) No, net reaction to the right. D) No, but there is no net reaction. E) Yes, net reaction to the right 76) For the reaction: 3 Fe(s) + 4 H2O(g) ? Fe3O4(s) + 4 H2(g) what is the effect of adding Fe(s)? A) The reaction shifts to the right. B) There is no change. C) The reaction shifts to the left. D) The Kp is decreased. E) The Kp is doubled. 77) At a certain temperature, Kc = 0.0500 and ?H = +39.6 kJ for the reaction below. 2MgCl2(s) + O2(g) ? 2MgO(s) + 2Cl2(g) Calculate Kc for the reaction MgO(s) + Cl2(g) ? MgCl2(s) + O2(g) and indicate whether the value will be larger or smaller at a lower temperature. A) 4.47, larger B) 400, smaller C) 0.224, larger D) 0.224, smaller 78) Two moles of NH3 are initially present for the reaction: 2 NH3(g) ? N2(g) + 3 H2(g) At equilibrium there is 1.00 mol NH3. How many moles of H2 are present at equilibrium? A) 3.00 B) 1.00 C) 1.50 D) 0.67 E) 0.75 79) In the reaction: 2 N2O(g) + N2H4(g) ? 3 N2(g) + 2 H2O(g), one starts with 0.10 mol N2O and 0.25 mol N2H4 in a 10.0 L container. If there are 0.06 mol N2O at equilibrium, how many moles of N2 are present? A) 0.02 B) 0.04 C) 0.06 D) 0.09 E) 0.07 80) For the reaction: PCl3(g) + Cl2(g) ? PCl5(g) at 70.5°C, Kp = 1.05. If one starts with 1.80 atm pressure of PCl3(g), 1.72 atm pressure of Cl2(g), and no PCl5(g), what is the partial pressure of PCl5(g) at equilibrium? A) 0.827 atm B) 0.856 atm C) 0.818 atm D) 0.599 atm E) 0.080 atm