Q. Aluminium chloride exists as dimer, $Al_{2}Cl_{6}$, in solid state as well as in solution of non-polar solvents such as benzene. When dissolved in water, it gives
A) $Al^{3 +} + 3Cl^{-}$
B) $\left\lbrack Al\left( H_{2}O \right)_{6} \right\rbrack^{3 +} + 3Cl^{-}$
C) $\left\lbrack Al(OH)_{6} \right\rbrack^{3 -} + 3HCl$
D) $Al_{2}O_{3} + 6HCl$
Explanation
(b)
$AlCl_{3}$ is covalent but in water, it becomes ionic due to large hydration energy of $Al^{3 +}$.
$AlCl_{3} + 6H_{2}O \rightleftharpoons \left\lbrack Al\left( H_{2}O \right)_{6} \right\rbrack^{3 +} + 3Cl^{-}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.