A metal salt with the formula  ${\text{MCl}}_{\text{2}}$ crystallizes from water to form a solid with the composition ${\text{MCl}}_{\text{2}}.{\text{6H}}_{\text{2}}\text{O}.$ The equilibrium vapour pressure of water above this solid at $\text{29}0\text{ K}$ is 0.1 atm. The value of ${\text{Δ}}_{r}G\left({\text{in kcal mol}}^{-\text{1}}\right)$for the reaction,

$MC{l}_2.6H_{2}O\left(s\right)\stackrel{ }{\rightleftharpoons }MC{l}_2\left(s\right)+6H_{2}O\left(g\right)$ at 0.1 atm pressure is _______.

$\left[\text{Given R}={\text{2 cal K}}^{-\text{1}}{\text{mol}}^{-\text{1}},\text{ lnx}=\text{2}.\text{3logx}\right]$