Chemistry - s Block Elements Question with Solution | TestHub

For any solution to become soluble in water hydration energy of the solution should me more than its lattice energy. Here the hydration energy of sodium sulphate is more than lattice energy but in case of barium sulphate lattice energy of barium sulphate is more than its hydration energy.  

For dissolution hydration energy must be more higher $(-\mathrm{ve})$ value than of lattice energy. Thus, (c) is the correct answer.