Q. In a mixture of acetic acid and sodium acetate the ratio of concentration of the salt to the acid is increased ten times. Then, the pH of the solution
A) Increases by one
B) Decreases by one
C) Decreases ten fold
D) Increased ten fold
Explanation
(a)
Mixture of acetic and sodium acetate is an acidic buffer. Hence, from Henderson equation,
$pH = pK_{a} + \log\frac{\lbrack salt\rbrack}{\lbrack acid\rbrack}$
On increasing [salt] ten times of that of [acid], the pH will increase by one.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.