The dissolution of
CaCl2⋅6H2O in a large volume of water is endothermic to the extent of
3.5kcal/mol. For the reaction
CaCl2(s)+6H2O(l)→CaCl2⋅6H2O(s),
ΔH is
−23.2kcal. The heat of solution of anhydrous
CaCl2 in a large quantity of water will be