Question

State the role of buffer solution in the given titration

Answer 1

Thanks for asking this informative question.It is mainly used to sustain the PH of the solution. It shows that the reaction is near to finishing point.
For example, in complexometric titration,  ammonia-ammonium chloride is used like a buffer to adjust PH approx. 10.
I expect this will prove useful for you.

Answer 2

A buffer solution is an aqueous solution which consists of a mixture of a weak acid and its conjugate base or the other way round.

It shows minimal changes in its PH when little amount of a strong acid or base is added to it.

This makes the solution necessary in keeping the PH at an almost constant value during the titration reaction