The enthalpies of solution for copper sulphate pentahydrate and anhydrous copper sulphate are respectively ` + 11.7` and `-65.5kJ mol^(-1)`.The hydration enthalpy of anhydrous copper suphate is
A. `53.8 kJ mol^(-1)`
B. ` - 9.8 kJ mol^(-1)`
C. ` - 77.2kJ mol^(-1)`
D. ` -53.8 kJ mol^(-1)`
