Question

The reason $SiC{l}_4$ is easily hydrolysed as compared to $CC{l}_4$ is that :

• A. the bonding in $SiC{l}_4$ is ionic
• B. silicon is non-metallic
• C. silicon can extend its coordination number beyond four
• D. silicon tetrachloride can form hydrogen bonds

Answer 1

The correct option is C silicon can extend its coordination number beyond four

A displacement reaction should take place. However, in both $SiC{l}_4$ and $CC{l}_4$, no dissociation takes place and the solution has no ions. The only possible way now is that an external group should attack this molecule and form a bond. The excess repulsive forces between the groups attached to the central atom, one group would leave to finish the displacement. Due to the presence of extra unfilled orbital in silicon, this is possible only in $SiC{l}_4$.