If the heat fo dissolution of anhydrous `CuSO_(4)` and `CuSO_(4).5H_(2)O` is `-15.89 kcal` and `2.80 kcal`, respectively, then the heat of hydration of `CuSO_(4)` to form `CuSO_(4).5H_(2)O` is

Options

A. `-13.09 " kcal " `
B. `-18. 69 " kcal " `
C. `+13.09 " kcal " `
D. `+18.69 " kcal " `

Answer

B

Explanation

(i) `CuSO_4 +aq rarr CuSO_4(aq). Delta H_1 =15.89 kcal `
(ii) `CuSO_4 +5H_2lO+aq rarr CuSO_4 .5H_2O`
`therefore Delta H = Delta H_1 - Delta H_2 =- 18.69 kcal `