Chemistry - Chemical Equilibrium Question with Solution | TestHub

$$\begin{array}{c}\text{Take}\text{logarithms:}\text{log}\text{S}\text{=}\text{log}\text{A}\text{-}\Delta \text{H/(2.303}\text{RT)}\text{A}\text{plot}\text{of}\text{log}\text{S}\text{against}\text{1/T}\text{has}\\ \text{slope}\text{-}\Delta \text{H/(2.303}\text{R)}\\ \text{The}\text{graph}\text{rises}\text{with}\text{1/T,}\text{so}\text{the}\text{slope}\text{is}\text{positive}\text{and}\Delta \text{H}\text{<}\text{0}\\ \text{Dissolution}\text{is}\text{exothermic,}\text{so}\text{solubility}\text{falls}\text{as}\text{temperature}\text{rises}\\ {\text{CuSO}}_{\text{4}}{\text{cdotp5H}}_{\text{2}}\text{O}\text{and}\text{sucrose}\text{dissolve}\text{endothermically,}\text{and}\text{NaCl}\text{has}\text{almost}\text{zero}\text{heat}\\ \text{of}\text{solution}\\ \text{CaO}\text{dissolves}\text{with}\text{release}\text{of}\text{heat,}\text{so}\text{the}\text{solute}\text{is}\text{CaO,}\text{option}\text{(d).}\end{array}$$