Chemistry - Thermochemistry Question with Solution | TestHub

The heat of solution of anhydrous ${\mathrm{CuSO}}_4$ and ${\mathrm{CuSO}}_4\cdot 5{\mathrm{H}}_2\mathrm{O}$ are $-70\mathrm{kJ}{\mathrm{mol}}^{-1}$ and $+12\mathrm{kJ}{\mathrm{mol}}^{-1}$ respectively. The heat of hydration of ${\mathrm{CuSO}}_4$ to ${\mathrm{CuSO}}_4\cdot 5{\mathrm{H}}_2\mathrm{O}$ is $-x\mathrm{kJ}$. The value of $x$ is ______ (nearest integer).