Under what condition buffer with highest buffer capacity is obtained ?

What do you understand by buffer capacity ?

A buffer solution can be obtained from

Solution of a weak acid and its anion (that is,its conjugate base) or of a base and its common cation are buffered. When we add a small amount of acid or base to any one of the, the pH of solution change very little. pH of buffer solution can be computed as for acidic buffer : pH=pK_(a)+ log.(["Conjugate base"])/(["Acid"]) for basic buffer : pOH=pK_(b)+log.(["Conjugate acid"])/([Base]) It is generly accepted that a has useful buffer cpacity (pH change resisting power) provided that the value of [salt or conjugate base] /[acid] for acidic buffer lies within the range of 1 : 10 to 1. Buffer capacity is maximum when [conjugate base] = [acid] Useful correct statement :

pH of a 1 L buffer solution changes from 4.5 to 4.6 when 0.2 mole of a strong base is added to it. Its buffer capacity will be

which can act as buffer ?

An acidic buffer is obtained on mixing :

The condition for minimum change in pH for a buffer solution is

When 2mol of HCI is added to 1L of an acidic buffer, its pH changes from 3.4 to 2.9 . The buffer capacity of the buffer solution is

When 0.002mol of acid is added to 250 mL of a buffer solution, pH decreases by 0.02 units. The buffer capacity of the system is

10 ml of 0.2 M acid is added to 250 ml of a buffer solution with pH = 6.34 and the pH of the solution becomes 6.32 . The buffer capacity of the solution is :