Question

Solubility of $NaCl$ in $D_{2}O$, compared with its solubility in $H_{2}O$ is:

• A. less
• B. equal
• C. more
• D. cannot be predicted

Answer 1

The correct option is A less

In order for an ionic compound to solubilise in solvent it has to first get in between the solvent molecules, for this in case of water molecules it has to break the O----H Hydrogen bond.

However, in the case of Heavy water, the O----D bond is slightly stronger and hence cannot be broken as easily as the H bond.

Hence the Na and Cl ions are less solvated making them less soluble in heavy water.