Question
Anhydrous $$AlC{l_3}$$ cannot be obtained from which of the following reactions ?
A.
Heating $$AlC{l_3}.6{H_2}O$$
B.
By passing dry $$HCl$$ over hot aluminium powder
C.
By passing dry $$C{l_2}$$ over hot aluminium powder
D.
By passing dry $$C{l_2}$$ over a hot mixture of alumina and coke
Answer :
Heating $$AlC{l_3}.6{H_2}O$$
Solution :
\[\begin{align}
& 2Al+6HCl\xrightarrow{\Delta ,air}2AlC{{l}_{3}}+3{{H}_{2}} \\
& 2Al+3C{{l}_{2}}\to 2AlC{{l}_{3}} \\
\end{align}\]

\[AlC{{l}_{3}}.6{{H}_{2}}O\xrightarrow{\Delta }Al{{\left( OH \right)}_{3}}+3HCl+3{{H}_{2}}O\]
Thus \[AlC{{l}_{3}}\] cannot be obtained by this method.