Question

Sodium chloride is soluble in water but not in benzene because

• A. $\Delta \text{H}_{\text{Solvation}} < \Delta \text{H}_{\text{Lattice energy}}$ in water and
  
  $\Delta \text{H}_{\text{Solvation}} > \Delta \text{H}_{\text{Lattice energy }}$ in benzene
• B. $\Delta \text{H}_{\text{Solvation}} > \Delta \text{H}_{\text{Lattice energy }}$ in water and
  
  $\Delta \text{H}_{\text{Solvation}} < \Delta \text{H}_{\text{Lattice energy}}$ in benzene
• C. $\Delta \text{H}_{\text{Solvation}} = \Delta \text{H}_{\text{Lattice energy }}$ in water and
  
  $\Delta \text{H}_{\text{Solvation}} < \Delta \text{H}_{\text{Lattice energy}}$ in benzene
• D. $\Delta \text{H}_{\text{Solvation}} < \Delta \text{H}_{\text{Lattice energy }}$ in water and
  
  $\Delta \text{H}_{\text{Solvation}} = \Delta \text{H}_{\text{Lattice energy }}$ in benzene

Answer 1

Answer: (B)

Hydration energy resolve during dissolution in the water while lattice energy gives the energy to break the crystal so

For a compound to be soluble, the solvation energy must be greater than the lattice energy. Since, NaCl is soluble in water but insoluble in benzene.

$\Delta \text{H}_{\text{Solvation}} > \Delta \text{H}_{\text{Lattice energy }}$ in water

and

$\Delta \text{H}_{\text{Solvation}} < \Delta \text{H}_{\text{Lattice energy}}$ in benzene