Question

In a buffer, if the ratio of salt and acid is increased $10$ times, then $pH$ will:

• A. increase by 10
• B. decrease by 10
• C. increase by one
• D. decrease by one

Answer 1

Answer: (C)

From Handerson's equation :
$pH=p{K}_a+\log \frac{\text{[Salt ]}}{\text{[ acid ]}}$
Hence, on increasing $\text{[Salt ]}\text{[ acid ]}$ by ten times $pH$ will increase by one.
(As, $\log \frac{\text{[Salt]}}{[\text{acid] }}$ will be equal to $\log 10$ i.e., one)