Although Sulphur contain vacant d-orbital but SF6 does not under go hydrolysis. Why ?

In SF₆ Sulphur atom contain vacant d-orbital but SF₆ does not undergo hydrolysis because Sulphur is sterically protected (Crowding) by six fluorine atoms and water molecules are unable to co-ordinate with vacant d-orbital of sulphur atom. Down the group in Suphur family extent of Hydrolysis increases due to increasing of size of central atoms crowding decrease. The order is as 

   [" SF₆ < SeF₆ < TeF₆ "]

Related Questions:

(1) What are the SESQUI OXIDES ? give the examples.

(2) Arrange in increasing order of extent of hydrolysis [ CCI4, MgCI2, AICI3, PCl5, SiCI4].

(3) Although Sulphur contain vacant d-orbital but SF6 does not under go hydrolysis. Why ?

(4) CCl4 can not be hydrolysed but SiCl4 can be. Why?

(5) Silianol (SiH3OH) is more acidic than methanol (CH3OH) why?

(6) What happened when Graphite treated concentrated acids like HNO3/HF or KMnO4 ?.

(7) Why Boric acid become strong acid in the presence of cis 1,2-diol or 1,3-diol ?

(6) What is the molecular formula of Borax ?

(9) What is oil of vitriol ?