Question

Which of the following chlorides cannot get hydrolysed ?

• A. $SnC{l}_4$
• B. $CC{l}_4$
• C. $PbC{l}_4$
• D. $SiC{l}_4$

Answer 1

The correct option is B $CC{l}_4$

The compounds given are the tetrahalides $MC{l}_4$ of group 14 elements. For the hydrolysis, (nucleophilic substitution) of $MC{l}_4$ the nature of the $M-Cl$ bond should be as
It must expand its covalency beyond 4 by the use of its vacant d-orbital which will accommodate the lone pair of electrons of $H_{2}O$ (the-nucleophile).
Here, M can be Si, Sn and Pb because they have vacant nd-orbital. But carbon is a member of second period (n=2, l=0, 1)
it does not have d-orbital(l = 2). So, $CC{l}_4$ will not be hydrolysed and correct option is (b).