`SF_(4)` undergoes hydrolysis but `SF_(6)` does not-why?

Explanation

In `SF_(6)` molecule, the S-atom remains surrounded by six F-atoms. Hence, `H_(2)O` fails to attack the S-atom due to steric hindrance. In `SF_(6)` , S-atom is coordinatively saturated and F-atom has no d -orbital to accept an unshared electron pair from `H_(2)O` . Hence, `SF_(6)` does not undergo hydrolysis.
On the other hand, in `SF_(4)` , the S-atom is surrounded by only four F-atoms and hence, the attack by water is not sterically hindered. In `SF_(4)` , S-atom is not coordinatively saturated. Hence, `SF_(4)` undergoes hydrolysis easily.