Give reasons for the following observations :
Why `SF_(4)` undergoes hydrolysis but not `SF_(6)`?
Or `SF_(6)` is inert towards hydroysis.
`SF_(6)` is much less reactive than `SF_(4)`.
Or (i) `SF_(4)` is easily hydrolysed whereas `SF_(6)` is not easily hydrolysed.
(ii) Sulpher exhibits greater tendency for calenation than selenium.
(iii) Sulpher has a higher tendency for catenation than oxygen.

Explanation

`SF_(6)` is kinetically an inert compound or is stable in nature. This is on account of the reason that six fluorine atoms around the central sulphur atom cause lot of steric hindrance to the attacking reagent. Therefore, `SF_(6)` does not readily take part in the chemical reactions.