Question

The enthalpy of solution of anhydrous $CuS{O}_4$ is $-$15.9 kCal and that of $CuS{O}_4.5H_{2}O$ is 2.8 kCal.
Calculate the enthalpy of hydration of $CuS{O}_4$

• A. $-28.7$ kCal / mole
• B. $-38.7$ kCal / mole
• C. $-8.7$ kCal / mole
• D. $-18.7$ kCal / mole

Answer 1

The correct option is D $-18.7$ kCal / mole

As given,

ethalpy of solution of anhydrous $CuS{O}_4$ $=-15.9kCal$

ethalpy of solution of $CuS{O}_4.5H_{2}O$ $=2.8kCal$

so

Enthalpy of hydration of $CuS{O}_4$ $=-15.9-2.8$

$=-18.7kcal/mole$