Chapter 18, Problem 101E

A metal salt with the formula MCl₂ crystallizes from water to form a solid with the composition ${\text{MCl}}_2\cdot 6{\text{H}}_2\text{O}$ . The equilibrium vapor pressure of water above this solid at 298 K is 18.3 mmHg. What is the value of $\Delta G$ for the reaction ${\text{MCl}}_2\cdot 6{\text{H}}_2\text{O(}s)\rightleftharpoons {\text{MCl}}_2(s)+6{\text{H}}_2\text{O}(g)$ when the pressure of water vapor is 18.3 mmHg? When the pressure of water vapor is 760.0 mmHg?