Question

Select the wrong statement about buffer capacity ($\beta$) when $C_{BOH}$ and $C_{HA}$ represents the number of mole of strong base or strong acid added to $1$ litre of buffer mixture.

• A. $\beta =\frac{d{C}_{BOH}}{dpH}$
• B. $\beta =-\frac{d{C}_{HA}}{dpH}$
• C. Buffer capacity is satisfactory over a $pH$ range of $p{K}_a\pm 1$
• D. In a buffer mixture, the salt is also hydrolysed to produce acid or base and thereby to influence buffer capacity

Answer 1

The correct option is D In a buffer mixture, the salt is also hydrolysed to produce acid or base and thereby to influence buffer capacity

A solution that resists change in pH value upon addition of small amount of strong acid or base (less than 1 %) or when solution is diluted is called buffer solution. The capacity of a solution to resist alteration in its pH value is known as buffer capacity and the mechanism of buffer solution is called buffer action.

In a buffer mixture, the salt's hydrolysis will be reduced due to presence of weak acid or base so they can not influence buffer capacity.