Question

Calculate the value of $\Delta G$ for following reaction at 300 K.
$H_{2}O_{(s)}\longrightarrow H_{2}O_{(l)}$
$(\Delta H=7\text{ kJ}, \Delta S=24.8\text{ J K}^{-1})$

• A. $0.74\text{ kJ mol}^{-1}$
• B. $-0.82\text{ kJ mol}^{-1}$
• C. $0.21\text{ kJ mol}^{-1}$
• D. $-0.44\text{ kJ mol}^{-1}$

Hint:

Logic Tip: The process is ice melting to water. The normal melting point of ice is $0^\circ\text{C}$ (273 K). At any temperature above 273 K (like the 300 K given here), melting is spontaneous. A spontaneous process MUST have a negative $\Delta G$. This immediately rules out options A and C.

Answer 1

The Correct Option is D