Question

The enthalpy change for the transition of liquid water to steam, ∆_vapH = 37.3 kJ mol⁻¹ at 373 K. The entropy change for the process is ____________.

Options

• 111.9 J mol⁻¹ K⁻¹

• 37.3 J mol⁻¹ K⁻¹

• 100 J mol⁻¹ K⁻¹

• 74.6 J mol⁻¹ K⁻¹

Answer 1

The enthalpy change for the transition of liquid water to steam, ∆_vapH = 37.3 kJ mol⁻¹ at 373 K. The entropy change for the process is 100 J mol⁻¹ K⁻¹.

Explanation:

∆_vapS = `(∆_"vap""H")/"T" = (37.3  "KJ mol"^-1)/(373  "K")`

= 0.1 kJ mol⁻¹ K⁻¹

= 100 J mol⁻¹ K⁻¹