SOLVED

41) Which of the following quantities for an element has a value of zero in the standard state? I)ΔH°f II)ΔG°f III)S° A) I only B) II only C) III only D) I and II E) I, II, and III 42) For Cl2O(g) + 3/2 O2(g) → 2 ClO2 ?H° = 126 kJ/mol, and ΔS° = -74.9 J/(mol?deg) at 377°C. What is Keq? A) 0.97 B) 6.12 × 10-7 C) 4.27 × 10-22 D) 9.17 × 10-15 E) 1.07 × 1014 43) Consider the reaction: N2(g) + 3 X2(g) → 2 NX3(g) ?H°0.00.0-43 kJ/mol S°192210172 J/(mol?K) What is Keq for this reaction at 591 K? A) 2.3 × 1017 B) 4.3 × 10-18 C) 1.04 D) 0.96 E) 132 44) For the reaction PCl5(g) → PCl3(g) + Cl2(g) at 298 K, Keq = 1.87 × 10-7, ΔS° = 1.8192 J/(mol ?K), what is ΔG° and is the reaction spontaneous? A) 3.84 × 104 kJ/mol, no B) 7.68 kJ/mol, no C) -7.68 kJ/mol, yes D) 38.4 kJ/mol, no E) -38.4 kJ/mol, yes 45) If the vapor pressure of water in an open system at 25°C is 23.8 mmHg, what is ΔG for the reaction below at 25°C? H2O(l) → H2O(g, 23.8 mmHg) A) 0 kJ/mol B) -8.58 kJ/mol C) +8.58 kJ/mol D) -0.720 kJ/mol 46) For the vaporization of water in an open system at 25°C and 1 atm, which of the following is correct? A) The reaction is entropy driven. B) The reaction is enthalpy driven. C) The reaction is not spontaneous. D) ΔG°rxn = 0 47) Consider the reaction of 25.0 mL of 0.20 M AgNO3(aq) with 25.0 mL of 0.20 M NaBr(aq) to form AgBr(s) at 25°C. What is ΔG for this reaction? The Ksp of AgBr is 5.0 x 10-13 at 25°C. A) -58.8 kJ/mol B) -70.2 kJ/mol C) +58.8 kJ/mol D) +70.2 kJ/mol 48) The equilibrium constant for the reaction below is 7.2 x 10-4 at 298 K and 1 atm. HNO2(aq) + H2O(l) ? NO2-(aq) + H3O+(aq) When [HNO2(aq)] = 1.0 M and [NO2-(aq)] = [H3O+(aq)] = 1.0 x 10-5 M, calculate ΔG. A) -39.1 kJ/mol B) +17.9 kJ/mol C) -17.9 kJ/mol D) +39.1 kJ/mol 49) Choose the INCORRECT statement. A) The van’t Hoff equation is ln = . B) Keq is independent of temperature. C) In a thermodynamic equilibrium constant expression, the activity of a gas is replaced by its partial pressure in atmosphere. D) In a Keq expression, the activity of a solution is replaced by its molarity. E) If ΔG = 0, the process is at equilibrium. 50) Which of the following quantities is generally independent of temperature? I) ΔH II) ΔS III) ΔG A) I only B) II only C) III only D) I and II E) I, II, and III