Question

What are the signs of ΔH, ΔS, and ΔG for the spontaneous conversion of a crystalline solid into a gas?

Answer 1

Answer:

ΔH>0, ΔS>0, and ΔG<0

Explanation:

Crystalline solid → Gas

• ΔG < 0 T  as the reaction is Spontaneous

• The solid is converted into gas so the Entropy will increase as randomness is more in gas than solid, ΔS > 0

using Gibbs equation

ΔG = ΔH - TΔS

as ΔG < 0 and ΔS > 0

ΔH - TΔS <0

ΔH < TΔS ⇒ΔH >0

This gives that ΔH will be Positive but it will be less than TΔS. So we need to provide some energy to convert crystalline solid into gas.