Multiple Choice
Consider 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.
19. Chemical Thermodynamics
Gibbs Free Energy Calculations
Back19. Chemical Thermodynamics
Gibbs Free Energy Calculations
- Multiple ChoiceWhich of the following conditions indicates that a chemical reaction is spontaneous at constant temperature and pressure?
- Multiple ChoiceWhich of the following conditions will result in a spontaneous reaction at standard conditions according to the Gibbs free energy equation ΔG°rxn = ΔH°rxn - TΔS°rxn?
- Multiple ChoiceWhat is the equilibrium constant (K) at 305 K when the standard Gibbs free energy change (ΔG°) is -4.75 kJ/mol?
- Multiple ChoiceWhat is the equilibrium constant (K) at 305 K when the standard Gibbs free energy change (ΔG°) is +1.61 kJ/mol?
- Multiple ChoiceCalculate the value of ΔG° at 281.0 °C for the formation of calcium chloride from its constituent elements: Ca(s) + Cl2(g) → CaCl2(s), given that at 25.0 °C, ΔH° is -795.8 kJ/mol and ΔG° is -748.1 kJ/mol.
- Multiple ChoiceGibbs free energy is a measure of the spontaneity of a chemical reaction. It is the chemical potential for a reaction and is minimized at equilibrium. The change in Gibbs free energy can be calculated by ΔG°_rxn = ΔH°_rxn - TΔS°_rxn where ΔG°_rxn is:
- Multiple ChoiceCalculate and report ΔrG°T for the dissolution of Ca(OH)2(s) in water at 25°C, given that ΔH° = -985.2 kJ/mol and ΔS° = -0.353 kJ/mol·K.
- Multiple ChoiceUsing the given reactions, calculate the standard free energy of formation, ΔG°f, for phosphoric acid (H3PO4). Given: 1. P4 (s) + 5 O2(g) → P4O10(s) ΔG° = -2697.0 kJ/mol 2. 2 H2(g) + O2(g) → 2 H2O(g) ΔG° = -457.18 kJ/mol 3. 6 H2O(g) + P4O10(s) → 4 H3PO4(l) ΔG° = ?
- 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?
1views - 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?
1views - 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 ChoiceGiven the reaction IF7(g) + I2(g) → IF5(g) + 2 IF(g) with ΔH°rxn = -89 kJ, ΔH°f for IF7(g) = -941 kJ/mol, and ΔH°f for IF5(g) = -840 kJ/mol, calculate the standard enthalpy of formation (ΔH°f) for IF(g).
- 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 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.
2views