Chapter 14 Quiz Key

Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Honors Chemistry Ch 14 Take Home Quiz Give the direction of the reaction, if K >> 1. The forward reaction is favored. The reverse reaction is favored. Neither direction is favored. If the temperature is raised, then the forward reaction is favored. If the temperature is raised, then the reverse reaction is favored. Express the equilibrium constant for the following reaction. 2 CH3Cl(g) + Cl2 (g) ? 2 CH2Cl2 (g) + H2 (g) K = K = K = K = K = Express the equilibrium constant for the following reaction. P(g) + 3/2 Cl2(g) ? PCl3(g) K = K = K = K = K = The equilibrium constant is given for one of the reactions below. Determine the value of the missing equilibrium constant. H2(g) + Br2(g) ? 2 HBr(g) Kc = 3.8 × 104 2 HBr(g) ? H2(g) + Br2(g) Kc = ? 1.9 × 104 5.3 × 10-5 2.6 × 10-5 6.4 × 10-4 1.6 × 103 The equilibrium constant is given for two of the reactions below. Determine the value of the missing equilibrium constant. A(g) + B(g) ? AB(g) Kc = 0.24 AB(g) + A(g) ? A2B(g) Kc = 3.8 2 A(g) + B(g) ? A2B(g) Kc = ? 4.0 0.91 3.6 16 0.63 What is ?n for the following equation in relating Kc to Kp? N2(g) + 3 H2(g) ? 2 NH3(g) 4 -4 -2 2 1 In which of the following reactions will Kc = Kp? H2(g) + I2(g) ? 2 HI(g) CH4(g) + H2O(g) ? CO(g) + 3 H2(g) N2O4(g) ? 2NO2(g) CO(g) + 2 H2(g) ? CH3OH(g) N2(g) + 3 H2(g) ? 2 NH3(g) The reaction below has a Kc value of 61. What is the value of Kp for this reaction at 500 K? N2(g) + 3 H2(g) ? 2 NH3(g) 15 61 28 3.6 × 10-2 1.9 × 10-2 Express the equilibrium constant for the following reaction. P4(s) + 5 O2(g) ? P4O10(s) K = K = K = [O2]-5 K = [O2]5 K = What is ?n for the following equation in relating Kc to Kp? P4(s) + 5 O2(g) ? P4O10(s) 3 4 -4 5 -5 Determine the value of Kc for the following reaction if the equilibrium concentrations are as follows: [N2]eq = 3.6 M, [O2]eq = 4.1 M, [N2O]eq = 3.3 × 10-18 M. 2 N2(g) + O2(g) ? 2 N2O(g) 2.2 × 10-19 4.5 × 1018 2.0 × 10-37 5.0 × 1036 4.9 × 10-17 Determine the value of Kp for the following reaction if the equilibrium concentrations are as follows: P(CO)eq = 6.8 × 10-11 atm, P(O2)eq = 1.3 × 10-3 atm, P(CO2)eq = 0.041 atm. 2 CO(g) + O2(g) ? 2 CO2(g) 3.6 × 10-21 2.8 × 1020 4.6 × 1011 2.2 × 10-12 3.6 × 10-15 Calculate the value of [N2]eq if [H2]eq = 2.0 M, [NH3]eq = 0.5 M, and Kc = 2. N2(g) + 3 H2(g) ? 2 NH3(g) 0.016 M 0.031 M 0.062 M 0.40 M 62.5 M Which of the following statements is TRUE? Dynamic equilibrium occurs when the rate of the forward reaction equals the rate of the reverse reaction. The equilibrium constant for the forward reaction is equal to the equilibrium constant for the reverse reaction. A reaction quotient (Q) larger than the equilibrium constant (K) means that the reaction will favor the production of more products. Dynamic equilibrium indicates that the amount of reactants and products are equal. All of the above are true. In a reaction mixture containing reactants and products, each at a concentration of 1M, what is the value of Q? -1 1 ? 0 It cannot be determined without concentrations. Which of the following statements is TRUE? If Q < K, it means the reverse reaction will proceed to form more reactants. If Q > K, it means the forward reaction will proceed to form more products. If Q = K, it means the reaction is at equilibrium. All of the above are true. None of the above are true. Consider the following reaction and its equilibrium constant: SO2(g) + NO2(g) ? SO3(g) + NO(g) Kc = 0.33 A reaction mixture contains 0.39 M SO2, 0.14 M NO2 , 0.11 M SO3 and 0.14 M NO. Which of the following statements is TRUE concerning this system? The reaction will shift in the direction of reactants. The equilibrium constant will decrease. The reaction will shift in the direction of products. The reaction quotient will decrease. The system is at equilibrium. Consider the following reaction, equilibrium concentrations, and equilibrium constant at a particular temperature. Determine the equilibrium concentration of H2O(g). C2H4(g) + H2O(g) ? C2H5OH(g) Kc = 9.0 × 103 [C2H4]eq = 0.015 M [C2H5OH]eq = 1.69 M 9.9 × 10-7 M 80. M 1.0 M 1.68 M 0.013 M Consider the following reaction: Xe(g) + 2 F2(g) ? XeF4(g) A reaction mixture initially contains 2.24 atm Xe and 4.27 atm F2. If the equilibrium pressure of Xe is 0.34 atm, find the equilibrium constant (Kp) for the reaction. 25 0.12 0.99 8.3 0.040 Consider the following reaction: COCl2(g) ? CO(g) + Cl2(g) A reaction mixture initially contains 1.6 M COCl2. Determine the equilibrium concentration of CO if Kc for the reaction at this temperature is 8.33 × 10-4. Calculate this based on the assumption that the answer is negligible compared to 1.6. 4.2 × 10-4 M 1.5 × 10-3 M 3.7 × 10-2 M 2.1 × 10-2 M 1.3 × 10-3 M The following reaction is exothermic. Which change will shift the equilibrium to the left? 2 SO2(g) + O2(g) ? 2 SO3(g) raising the temperature adding SO3 removing O2 all of the above none of the above Identify the change that will always shift the equilibrium to the right. remove reactant increase product remove product increase pressure increase volume Consider the following reaction at equilibrium. What effect will adding more SO3 have on the system? SO2(g) + NO2(g) ? SO3(g) + NO(g) The reaction will shift in the direction of products. The reaction will shift to decrease the pressure. No change will occur since SO3 is not included in the equilibrium expression. The reaction will shift in the direction of reactants. The equilibrium constant will decrease. Consider the following reaction at equilibrium. What effect will removing NO2 have on the system? SO2(g) + NO2(g) ? SO3(g) + NO(g) The reaction will shift in the direction of products. The reaction will shift to decrease the pressure. No change will occur since SO3 is not included in the equilibrium expression. The reaction will shift in the direction of reactants. The equilibrium constant will decrease. Consider the following reaction at equilibrium. What effect will reducing the volume of the reaction mixture have on the system? CuS(s) + O2(g) ? Cu(s) + SO2(g) The equilibrium constant will decrease. No effect will be observed. The reaction will shift to the right in the direction of products. The equilibrium constant will increase. The reaction will shift to the left in the direction of reactants. Consider the following reaction at equilibrium. What effect will increasing the pressure of the reaction mixture have on the system? CuS(s) + O2(g) ? Cu(s) + SO2(g) The equilibrium constant will decrease. No effect will be observed. The reaction will shift to the right in the direction of products. The equilibrium constant will increase. The reaction will shift to the left in the direction of reactants. Consider the following reaction at equilibrium. What effect will adding 1 mole of Ar to the reaction mixture have on the system? 2 H2S(g) + 3 O2(g) ? 2 H2O(g) + 2 SO2(g) The reaction will shift to the right in the direction of products. No effect will be observed. The reaction will shift to the left in the direction of reactants. The equilibrium constant will decrease. The equilibrium constant will increase. Consider the following reaction at equilibrium. What effect will increasing the temperature have on the system? Fe3O4(s) + CO(g) ? 3 FeO(s) + CO2(g) ?H°= +35.9 kJ The reaction will shift to the left in the direction of reactants. The equilibrium constant will increase. The equilibrium constant will decrease. No effect will be observed. The reaction will shift to the right in the direction of products. Short Answer Questions Explain dynamic equilibrium. Use the generic reaction A(g) ? B(g) to explain. Answer: In this reaction, dynamic equilibrium means that the ratio of [B]/[A] is constant. Even though the ratio of their concentrations is constant, the forward and reverse reactions continue to occur. The rates of the forward and reverse reactions are equal in order to keep the ratio of [B]/[A] constant. Why aren't solids or liquids included in an equilibrium expression? The equilibrium constant relates different concentrations of reactants and products to one another. Since the concentrations of liquids and solids are constant, their concentration(s) becomes part of the constant value of the equilibrium constant. 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6