Question

Why does the solubility of noble gases in water increase with increase in the atomic number?

Answer 1

1. Noble gases dissolve in water due to dipole-induced dipole interaction.
2. Water molecules are polar and induce a dipole in noble gas atoms by attracting their electron clouds.
3. Larger noble gas atoms (with higher atomic numbers) have bigger and more easily distorted electron clouds.
4. Because of this, larger atoms are more easily polarized and form stronger induced dipoles.
5. Stronger induced dipoles lead to stronger attraction between noble gas atoms and water molecules.
6. As a result, solubility increases from helium to xenon with increasing atomic number.

This explains why the solubility of noble gases in water increases as atomic number increases.