Question

Which of the following alkaline earth metal sulphates has hydration enthalpy higher than the lattice enthalpy?

• A. $SrS{O}_4$
  
• B. $CaS{O}_4$
  
• C. $BeS{O}_4$
  
• D. $BaS{O}_4$
  

Answer 1

The correct option is C $BeS{O}_4$


Compound with hydration energy higher than its lattice energy is soluble in water. Among the given compounds, only berrylium sulphate is fairly soluble in water and hence the hydration of $BeS{O}_4$ is higher than its lattice energy. Within group $2$, the hydration energy decreases down the group while lattice energy is almost the same.