Q. Sodium chloride is soluble in water but not in benzene because
A) $\mathrm{\Delta}H_{hdydration} < \mathrm{\Delta}H_{lattice\ energy\ in\ water}\ and\ \mathrm{\Delta}H_{hdydration} > \mathrm{\Delta}H_{lattice\ energy\ in\ benzene}\$
B) $\mathrm{\Delta}H_{hdydration} > \mathrm{\Delta}H_{lattice\ energy\ in\ water}\ and\ \mathrm{\Delta}H_{hdydration} < \mathrm{\Delta}H_{lattice\ energy\ in\ benzene}$
C) $\mathrm{\Delta}H_{hdydration} = \mathrm{\Delta}H_{lattice\ energy\ in\ water}\ and\ \mathrm{\Delta}H_{hdydration} < \mathrm{\Delta}H_{lattice\ energy\ in\ benzene}$
D) $\mathrm{\Delta}H_{Hdydration} < \mathrm{\Delta}H_{lattice\ energy\ in\ water}\ and\ \mathrm{\Delta}H_{Hdydration} = \mathrm{\Delta}H_{lattice\ energy\ in\ benzene}$
Explanation
(b)
For a compound to be soluble, the hydration energy must be greater than the lattice energy. Since, NaCl is soluble in water but insoluble in benzene.
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \mathrm{\Delta}H_{hydration} > \mathrm{\Delta}H_{lattice\ energy\ in\ water}\$
$and\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \mathrm{\Delta}H_{hydration} < \mathrm{\Delta}H_{lattice\ energy\ in\ benzene}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.