Question

0.002 mole of acid is added to a litre of buffer solution. This decreases the pH of the buffer by 0.02. Then the buffer capacity is:

• A. 0.2
• B. 0.1
• C. 0.6
• D. 0.4

Answer 1

The correct option is B 0.1

The expression for the buffer capacity is,

Buffer capacity $=\frac{\text{Number of moles of acid or base added per litre}}{\text{Change in pH}}$

Substitute values in the above expression.

Buffer capacity $=\frac{0.002}{0.02}=0.1$.

Hence, the correct option is $\text{B}$