Question

The percentage degree of hydrolysis of a salt of weak acid $\left(HA\right)$ and weak base $\left(BOH\right)$ in its $0.1M$ solution is found to be $10\text{\%}$. If the molarity of the solution is $0.05M$, the percentage hydrolysis of the salt should be:

• A. $5\text{\%}$
• B. $10\text{\%}$
• C. $20\text{\%}$
• D. none of the above

Answer 1

The correct option is B $10\text{\%}$

The degree of hydrolysis $h$ for a salt of weak acid with weak base is given by the expression $K_h=\frac{K_w}{K_a{K}_b}$.
Thus, it is independent of the molar concentration.
Hence, when the molarity of the solution is $0.05$ M, the percentage degree of hydrolysis will be $10$