Q40 / 180 · JIPMER 2016 · Chemistry
Aqueous solution of $\mathrm{AlCl}_3$ is acidic towards litmus while of NaCl is not. The correct reason behind this is
- A$\mathrm{AlCl}_3$ furnishes $\mathrm{OH}^{-}$ion in the solution
- Correct answerB$\mathrm{AlCl}_3$ furnishes $\mathrm{H}^{+}$ion in the solution
- C$\mathrm{AlCl}_3$ furnishes both $\mathrm{H}^{+}$well as $\mathrm{OH}^{-}$ion in the solution
- D$\mathrm{AlCl}_3$ is the salt of strong base and strong acid
Solution
$\mathrm{AlCl}_3$ is the salt of weak base and strong acid which renders $\mathrm{H}^{+}$ions on hydrolysis. Thus, aqueous solution of $\mathrm{AlCl}_3$ is acidic in nature.
$\mathrm{Al}^{3+}+3 \mathrm{H}_2 \mathrm{O} \rightleftharpoons \mathrm{Al}(\mathrm{OH})_3+3 \mathrm{H}^{+}$
On the other hand, NaCl is the salt of strong acid and strong base which does not undergo hydrolysis.
Hence, the correct answer is option: 'B'.