Question

Assign a reason for the following:

SF₆ is not easily hydrolysed.

Answer 1

1. Sulphur in SF₆ has an expanded octet with six strong S-F bonds, making the molecule very stable.
2. The size of fluorine atoms around sulphur creates a steric hindrance, blocking water molecules from attacking the sulphur.
3. SF₆ has an octahedral symmetrical structure which resists nucleophilic attack by water.
4. Though thermodynamically hydrolysis is favourable, kinetic inertness due to these factors makes SF₆ hydrolysis very slow.

Thus, SF₆ is kinetically stable and not easily hydrolysed.