Question

The degree of hydrolysis for a salt of strong acid and weak base
A. Is independent of dilution
B. Increases with dilution
C. Increases with decrease in \[{K_b}\] of the bases
D. Decreases with a decrease in temperature

Answer 1

Hint: The degree of hydrolysis for a salt of strong acid and a weak base is inversely proportional to the dissociation constant of the base. Thus, the degree of hydrolysis increases with a decrease in the value of \[{K_b}\]. The base dissociation constant (\[{K_b}\]) defines how the ions that make up the base split into positive and negative components.

Complete Step by Step Solution:
The degree of hydrolysis of salt is defined as the proportion of the salt which is hydrolyzed at equilibrium and what proportion of the salt dissociates into its corresponding ions, once it is dissolved in the water.
For a salt of strong acid and a weak base, the relation between the degree of hydrolysis and \[{K_b}\]can be written as:
\[h = \sqrt {\dfrac{{{K_w}}}{{{K_b} \times C}}} \]
In this relation, h = degree of hydrolysis of salt
C= Concentration of the solution
\[{K_W}\] = ionic product of water
The degree of hydrolysis for the salt of a strong acid and a weak base increases with an increase in the temperature and also with dilution. In the above relation, it is clearly visible that the degree of hydrolysis for a salt of strong acid and a weak base is inversely proportional to the dissociation constant of the base (\[{K_b}\]).
Thus, the correct answer to this question is, the option is (C).

Note: Whenever a salt of strong acid and a weak base is dissolved in water, it undergoes dissociation and forms its corresponding oppositely charged ions. But, it cannot undergo complete dissociation and therefore depends on its degree of hydrolysis which decides how much part of the salt is actually reactive.