19. Chemical Thermodynamics

What is the entropy change (ΔS) of a reaction that has an enthalpy change (ΔH) of -70 kJ and a Gibbs free energy change (ΔG) of 18 kJ at a constant temperature of 76 degrees Celsius?

Which of the following conditions indicates that a chemical reaction is spontaneous at constant temperature and pressure?

Calculate the value of ΔG° at 241.0°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, ΔG° is -748.1 kJ/mol, and ΔS° is -159.8 J/K.

Given ΔH°rxn = -95 kJ, ΔS°rxn = 157 J/K, and T = 855 K, calculate the change in Gibbs free energy (ΔG) and predict whether this reaction is spontaneous at the given temperature. Choose from the following options:

For 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?

Given that the equilibrium constant, Keq, for a reaction at 25°C (298 Kelvin) is 740, what is the standard Gibbs free energy change, ΔG°', for the reaction? Provide your answer to two decimal places.

What is the change in Gibbs free energy, ΔG, at 25°C for the reaction N₂(g) + 3 H₂(g) → 2 NH₃(g) given ΔH = -92.22 kJ and ΔS = -198.75 J/K?

Given the equilibrium concentrations of A and B as 0.0354 M and 0.121 M, respectively, for the reaction A(g) ⇌ B(g), what is the standard Gibbs free energy change (ΔG°) at 25°C?

The dissolution of ammonium nitrate is given by the reaction: NH4NO3(s) -> NH4+(aq) + NO3-(aq). Assuming that the values of ΔH° and ΔS° do not change appreciably with temperature, which of the following is the correct expression to calculate the ΔG° value for the reaction?

What is the equilibrium constant (K) at 305 K when the standard Gibbs free energy change (ΔG°) is +4.87 kJ/mol?

Calculate the Gibbs free energy change associated with the formation of 2.0 g of CO2 from the reaction: 2 CO(g) + O2(g) -> 2 CO2(g); given ΔG° = -514.4 kJ for the formation of 2 moles of CO2.

What is ΔG° (in kJ/mol) for a redox reaction where two electrons are transferred with E°cell = -0.206 V?

Consider 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.

Calculate ΔG° (in kJ) for a reaction where ΔH°= +63 kJ, ΔS°= +675 J/K, and T = 298 K. Use the formula ΔG° = ΔH° - TΔS°.