Question

Which of the following will occur if a 1.0 M solution of a weak acid is diluted to 0.01 M at constant temperature:-

• A. Percentage ionisation will increase
• B. [H+] will decrease to $0.01$ M
• C. $K_a$ will increase
• D. pH will decrease by $2$ units

Answer 1

The correct option is A Percentage ionisation will increase

$\alpha =$ ionisation

$\alpha =\sqrt{Ka/C}$

Now

if C decreases , then $\alpha$increases hence, % ionisation will increase.