Multiple Choice
Calculate ∆G° for the following reaction: P4 (s) + 5 O2 (g) → P4O10 (s), ∆H° = −2940 kJ/mol, 25 °C.
Does the reaction favor reactants or products?
19. Chemical Thermodynamics
Gibbs Free Energy Calculations
Back19. Chemical Thermodynamics
Gibbs Free Energy Calculations
- Multiple Choice
Determine if reaction is spontaneous under standard conditions, if not at what temperature will it be spontaneous?
3 A (g) + 5 B (s) → 3 AB (s) + B2 (g) ∆H° = 112.7 kJ, ∆S° = 78.3 J/K.
- Multiple Choice
Nickel has ∆Hvap = 370.4 kJ/mol and ∆Svap = 123.3 J/mol•K. Will nickel boil at 2700 °C and 1 atm?
- Multiple Choice
Fe2O3 (s) + 3 H2 (g) → 2 Fe (s) + 3 H2O (g) is a redox reaction. What would be its Gibbs Free energy change under standard conditions? Is the reaction spontaneous at 25 °C?
- Multiple ChoiceCalculate the standard free-energy change (ΔG°) at 25 °C for the reaction: Mg(s) + Fe²⁺(aq) → Mg²⁺(aq) + Fe(s). Given: E°(Mg²⁺/Mg) = -2.37 V and E°(Fe²⁺/Fe) = -0.44 V.
- Multiple ChoiceCalculate ΔG° (in kJ) for a reaction where ΔH°= +63 kJ, ΔS°= +675 J/K, and T = 298 K. Use the formula ΔG° = ΔH° - TΔS°.
- Multiple ChoiceCalculate ΔG° (in kJ) for a reaction where ΔH° = -87 kJ, ΔS° = -223 J/K, and T = 298 K.
- Multiple ChoiceCalculate ΔG°rxn for the reaction: CaCO3(s) --> CaO(s) + CO2(g). Use the following reaction and given ΔG°rxn value: Ca(s) + CO2(g) + 1/2 O2(g) --> CaCO3(s) ΔG°rxn = -734.4 kJ. Assume ΔG°f for CaO(s) is -604.0 kJ/mol and ΔG°f for CO2(g) is -394.4 kJ/mol.
- Multiple ChoiceConsider the following reaction: CO2(g) + CCl4(g) ⇌ 2COCl2(g). Calculate ΔG for this reaction at 25 °C under these conditions: PCO2 = 0.140 atm, PCCl4 = 0.185 atm, PCOCl2 = 0.755 atm. Given that ΔG°f for CO2(g) is −394.4 kJ/mol, what is the value of ΔG?
- Multiple ChoiceConsider the following reaction: C2H4(g) + H2(g) → C2H6(g) with ΔH = -137.5 kJ and ΔS = -120.5 J/K. Calculate ΔG at 25 °C and determine whether the reaction is spontaneous.
- Multiple ChoiceConsider the following reaction: I2(g) + Cl2(g) ⇌ 2ICl(g) with Kp = 81.9 at 25 °C. Calculate ΔG⁰rxn for the reaction at 25 °C under equilibrium conditions. Express your answer in kilojoules.
- Multiple ChoiceConsider the following reaction: I2(g) + Cl2(g) ⇌ 2ICl(g) with Kp = 81.9 at 25 °C. Calculate ΔG⁰rxn for the reaction at 25 °C under standard conditions.
- Multiple ChoiceConsider the oxidation of NO to NO2: NO(g) + 1/2 O2(g) → NO2(g). Calculate ΔG°rxn at 25 °C given the following standard Gibbs free energies of formation: ΔG°f(NO) = 86.6 kJ/mol, ΔG°f(O2) = 0 kJ/mol, ΔG°f(NO2) = 51.3 kJ/mol.
- Multiple ChoiceFor the vaporization of benzene, ΔHvap = 30.7 kJ/mol and ΔSvap = 87.0 J/(K·mol). Does benzene boil at 75 °C and 1 atm pressure?
- Multiple ChoiceWhich of the following conditions indicates that a chemical reaction is spontaneous at constant temperature and pressure?