Q. The pH of 0.1 M solution of the following salts increases in the order
A) $NaCl < {NH}_{4}Cl < NaCN < HCl$
B) $HCl < NH_{4}Cl < NaCl < NaCN$
C) $NaCN < {NH}_{4}Cl < NaCl < HCl$
D) $HCl < NaCl < NaCN < {NH}_{4}Cl$
Explanation
(b)
$HCl$ is strong acid. In its 0.1 M solution, $\left\lbrack H^{+} \right\rbrack = 0.1\ M\ and\ hence,\ pH = 1\ NH_{4}Cl(aq)$ hydrolysis in solution and give acidic solution which is less than 0.1 M HCl. $NaCl\$is not hydrolysed in aqueous solutions. Its pH=7. $NaCN$ undergoes hydrolysis in solution to give alkaline solution. So, the pH increases in the order
$HCl < NH_{4}Cl < NaCl < NaCN\$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.