The lattice enthalpy and hydration enthalpy of four compounds are given below

The pair of compounds which is soluble in water is

Options

A. P and Q
B. Q and R
C. R and S
D. P and R

Explanation

The solubility of a compound mainly depends upon its hydration energy . If the hydration energy of a compound is greater than from its lattice enthalpy , then it is soluble in water . Thus for solubility hydration enthalpy `gt` lattice enthalpy For compounds P and R hydration enthalpy exceeds the lattice enthalpy , so they are soluble in water .