Question

Calculate the ΔG for the following system. Then state if the system is spontaneous or not spontaneous. ΔH = 147 kJ ΔS = -67.0 J/K T = 149 °C

Answer 1

Answer:

ΔG for the given system is 28.421 kJ. The system is non spontaneous.

Explanation:

ΔH = 147 kJ =147,000 J= Enthalpy of the system

ΔS = -67.0 J/K = Entropy change

T = 149 °C = 422.15 K = Temperature of the system

((T)°C=273.15 +T K)

ΔG = Gibbs free energy ?

The Gibbs free energy 's expression is given by:

ΔG = ΔH  - T ΔS

• ΔG > 0 , non spontaneous
• ΔG < 0, spontaneous

$\Delta G^o=147,000 J-422.15 K\times (-67.0)$

ΔG = 28,421 J = 28.421 kJ

Since, value of Gibbs free energy is positive this means that reaction is non spontaneous.