Question

Four solutions of $N{H}_{4}Cl$ are taken with concentrations $1M,0.1M,0.01Mand0.001M$. Their degree of hydrolysis are $h_1,h_2,h_3$ and $h_4$. What is the decreasing order of degree of hydrolysis ?

• A. $h_1>h_2>h_3>h_4$
• B. $h_1=h_2=h_3=h_4$
• C. $h_4>h_3>h_2>h_1$
• D. $\text{None of these}$

Answer 1

The correct option is C $h_4>h_3>h_2>h_1$

$N{H}_{4}Cl\to$ Salt of strong acid, $HCl$ and weak base $N{H}_{4}OH$
$\to$ Degree of hydrolysis, $h=\sqrt{\frac{k_h}{C}}=\sqrt{\frac{k_w}{k_{b}C}}$
$\to$ Higher the concentration, lower will be the degree of hydrolysis.
Hence, $h_1<h_2<h_3<h_4$