Question

SF6 is not easily hydrolysed whereas SF4 is easily hydrolysed...why...???

Answer 1

Hope it helps you!
SF6 Sulphur is surrounded by 6atoms whereas in SF4 it is by 4 atoms when we hydrolysed both compound then in case of SF6 water molecules find very less gap to attack on central atom, hence it is not easily hydrolysed.

Answer 2

$SF_6$ is not easily hydrolysed due to steric hindrance.

• $SF_6$ is surrounded by six highly electro negatives F atoms. This F atom surrounded the Sulfur atom and the water can not attack easily. So, $SF_6$ is not hydrolysed easily.
• $SF_4$ is surrounded by four highly electro negatives F atoms. This F atom surrounded the Sulfur atom partially and the water can attack easily. So, $SF_4$ is hydrolysed easily.