Question

Which of the following is not true about anhydrous aluminium chloride?

• A. It does not exist as $AlC{l}_3$ molecules in solid state
• B. On hydrolysis $AlC{l}_3$ gives $AlC{l}_3.3H_{2}O$
• C. The rate of sublimation of $AlC{l}_3$ increases with increase in temperature
• D. It is a strong Lewis acid

Answer 1

The correct option is B

On hydrolysis $AlC{l}_3$ gives $AlC{l}_3.3H_{2}O$

a) In solid state $AlC{l}_3$ exists as a dimer thus it exists as $A{l}_{2}C{l}_6$ rather than $AlC{l}_3$.

b) $AlC{l}_3$ is hydrolysed to aluminium hydroxide and HCl.
the corresponding reaction is,
$AlC{l}_3+3H_{2}O\to Al(OH{)}_3+3HCl$

c) $AlC{l}_3$ sublimates at high temperature under vacuum. The sublimation rate of $AlC{l}_3$ increases with increase in temperature.

d) $AlC{l}_3$ is basically a electron defficient compound. It has only 6 valence electrons. Thus it has the tendency to accept electrons and hence it acts as a lewis acid.