Question

STATEMENT-$1$ : $pH$ of aqueous solution of acetic acid increases with dilution and
STATEMENT-$2$ : The degree of ionization of acetic acid increases with dilution
$\left( A \right)$ Statement-$1$ is true, Statement-$2$ is True, Statement- $2$ is a correct explanation for Statement-$1$
$\left( B \right)$ Statement-$1$ is true, Statement-$2$ is true, Statement- $2$ is not a correct explanation for Statement-$1$
$\left( C \right)$ Statement-$1$ is true, Statement-$2$ is false
$\left( D \right)$ Statement-$1$ is false, Statement-$2$ is true

Answer 1

Ostwald’s dilution law is the application of the law of mass action to weak electrolyte in solution. Acetic acid is a weak electrolyte which dissociates into $C{H_3}CO{O^ - }$ and ${H^ + }$ ions. According to the Ostwald’s dilution law degree of dissociation of a weak electrolyte is proportional to the square of dilution.

Complete step by step answer:
In the given question we have given two statements, Let us see them one by one. In first statement it is given that $pH$ of aqueous solution of acetic acid increases with dilution it is false because when an acidic solution of is diluted with water the concentration of ${H^ + }$ ion decrease so, $pH$ of the solution increase toward $7$ . Thus we can say that $pH$ of acetic acid is increased on dilution.
Now let us discuss statement$2$, In this statement it is given that the degree of ionization of acetic acid increases with dilution because it is a weak electrolyte, According to Ostwald dilution law the degree of ionization goes on increase with dilution
$\alpha = \sqrt {KV}$

Where $\alpha$ is the degree of ionization, $V$ is the volume and $K$ is the dissociation constant of weak acid.
So, the given first and second statement is true but the second statement is not the correct explanation of the first statement.
Therefore, the correct option is $B.$

Note:
The degree of ionization also known as ionization yield in the literature refers to the proportionality of neutral particles, such as those in an aqueous solution, that are ionized to charged particles. For an electrolyte it could be understood as a capacity of acid and base ionize itself.