Question

Calculate the change in Gibbs free energy for each of the following sets of ΔHrxn°, ΔS°rxn, and T. Predict spontaneity.

a. ΔH°rxn= −86 kJ, ΔS°rxn= −142 J/K, T= 306 K
b. ΔH°rxn= −86 kJ, ΔS°rxn= −142 J/K, T= 856 K
c. ΔH°rxn= 86 kJ, ΔS°rxn= −142 J/K, T= 306 K
d. ΔH°rxn= −86 kJ, ΔS°rxn= −142 J/K, T= 390 K

Answer 1

The calculated change in Gibbs free energy for each set of ΔHrxn°, ΔS°rxn, and T, along with the spontaneity We can use the equation: ΔG = ΔH - TΔSprediction.

Step-by-step explanation:

To calculate the change in Gibbs free energy (ΔG) for each set of ΔHrxn°, ΔS°rxn, and T, we can use the equation: ΔG = ΔH - TΔS. Let's calculate the change in Gibbs free energy for each case:

a. ΔH°rxn = -86 kJ, ΔS°rxn = -142 J/K, T = 306 K:

ΔG = -86 kJ - (306 K)(-142 J/K) = -86 kJ + 43,752 J = 43,666 J

b. ΔH°rxn = -86 kJ, ΔS°rxn = -142 J/K, T = 856 K:

ΔG = -86 kJ - (856 K)(-142 J/K) = -86 kJ + 121,552 J = 121,466 J

c. ΔH°rxn = 86 kJ, ΔS°rxn = -142 J/K, T = 306 K:

ΔG = 86 kJ - (306 K)(-142 J/K) = 86 kJ + 43,752 J = 43,838 J

d. ΔH°rxn = -86 kJ, ΔS°rxn = -142 J/K, T = 390 K:

ΔG = -86 kJ - (390 K)(-142 J/K) = -86 kJ + 55,380 J = 55,294 J