Chemistry - Thermochemistry Question with Solution | TestHub

Calculate the enthalpy of precipitation of ${\mathrm{CaCO}}_3(\mathrm{s})$ (in $\mathrm{kcal}{\mathrm{mol}}^{-1}$).

${\mathrm{Ca}}^{2+}$ (aq.) + ${\mathrm{CO}}_3^{2-}$ (aq.) $\to$${\mathrm{CaCO}}_3$ (s)

Given: ${\Delta }_{\mathrm{f}}{H}^{\circ }$ (${\mathrm{Ca}}^{2+}$, aq.) = –130 $\mathrm{kcal}{\mathrm{mol}}^{-1}$

${\Delta }_{\mathrm{f}}{H}^{\circ }$ (${\mathrm{CO}}_3^{2-}$, aq.) = –160 $\mathrm{kcal}{\mathrm{mol}}^{-1}$

${\Delta }_{\mathrm{f}}{H}^{\circ }$ (${\mathrm{CaCO}}_3$, s) = –285 $\mathrm{kcal}{\mathrm{mol}}^{-1}$