Question

Calculate the change in Gibbs free energy for each of the following sets of ΔH∘rxn, ΔS∘rxn, and T. (Assume that all reactants and products are in their standard states.)

Part A: ΔH∘rxn= 130 kJ ; ΔS∘rxn=− 254 J/K ; T= 299 K

Express your answer as an integer.

Part B:  ΔH∘rxn=− 130 kJ ; ΔS∘rxn= 254 J/K ; T= 299 K

Express your answer as an integer.

Part C:  ΔH∘rxn=− 130 kJ ; ΔS∘rxn=− 254 J/K ; T= 299 K

Express your answer as an integer.

Part D:  ΔH∘rxn=− 130 kJ ; ΔS∘rxn=− 254 J/K ; T= 608 K

Express your answer as an integer.

Answer 1

A)

ΔHo = 130 KJ

ΔSo = -254 J/K

= -0.254 KJ/K

T = 299 K

use:

ΔGo = ΔHo - T*ΔSo

ΔGo = 130 - 299.0 * -0.254

ΔGo = 206 KJ

Answer: 206 KJ

B)

ΔHo = -130.0 KJ

ΔSo = 254 J/K

= 0.254 KJ/K

T = 299 K

use:

ΔGo = ΔHo - T*ΔSo

ΔGo = -130.0 - 299.0 * 0.254

ΔGo = -206 KJ

Answer: -206 KJ

C)

ΔHo = -130.0 KJ

ΔSo = -254 J/K

= -0.254 KJ/K

T = 299 K

use:

ΔGo = ΔHo - T*ΔSo

ΔGo = -130.0 - 299.0 * -0.254

ΔGo = -54.1 KJ

Answer: -54 KJ

D)

ΔHo = -130.0 KJ

ΔSo = -254 J/K

= -0.254 KJ/K

T = 608 K

use:

ΔGo = ΔHo - T*ΔSo

ΔGo = -130.0 - 608.0 * -0.254

ΔGo = 24.4 KJ

Answer: 24 KJ