Question

The molecule, which is not hydrolysed by water at $25^{\circ }C$ is

• A. $AlC{l}_3$
• B. $SiC{l}_4$
• C. $B{F}_3$
• D. $S{F}_6$

Answer 1

Answer: (D)

The moelcule, which is not hydrolysed by water at $25^{\circ }C$ is $S{F}_6$. This is because it is kinetically stabilised, attack at $S$ is impossible due to steric Hindrance and also because of the rigidity of $F-SF$ angles.
The hydrolysed product of other molecules are as follows :
$AlC{l}_3+H_{2}O⟶Al(OH{)}_3+HCl$
$SiC{l}_4+2H_{2}O⟶4HCl+Si{O}_2$
$B{F}_3+H_{2}O⟶H_{3}B{O}_3+HB{F}_4$