Question

The normal boiling point of acetic acid is 118.1°C. If a sample of the acetic acid is at 125.2°C, predict the signs of ΔH, ΔS, and ΔG for the boiling process at this temperature

Answer 1

The question is incomplete; the complete question is;

The normal boiling point of acetic acid is 118.1°C. If a sample of the acetic acid is at 125.2°C, predict the

signs of ∆H, ∆S, and ∆G for the boiling process at this temperature.

A. ∆H > 0, ∆S > 0, ∆G < 0

B. ∆H > 0, ∆S > 0, ∆G > 0

C. ∆H > 0, ∆S < 0, ∆G < 0

D. ∆H < 0, ∆S > 0, ∆G > 0

E. ∆H < 0, ∆S < 0, ∆G > 0

Answer:

∆H > 0, ∆S > 0, ∆G < 0

Explanation:

If we look at the question carefully, we will observe that it deals with a phase change from liquid to vapour phase.

Energy is required to break the intermolecular bonds in the liquid as it changes into vapour hence the process is endothermic, ∆H>0.

Also, the entropy of the vapour phase is greater than that of the liquid phase hence there is a positive change in entropy, ∆S>0.

Lastly, the process is spontaneous, hence the change in free energy ∆G is less than zero.