Q. Which of the following will occur if a 0.1 M solution of weak acid is diluted to 0.01 M at constant temperature?
A) $pH$ will increase
B) $K_{a}$ will decrease
C) $\lbrack H^{+}\rbrack$ will decrease to 0.01 M
D) % ionisation will increase
Explanation
(d)
For weak acid,
$\alpha = \sqrt{\frac{K_{a}}{C}}$
As $'C'$ decreases, $\alpha$ increases therefore, percentage ionisation will increase
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.