Question

Which of the following is correct regarding buffer solution?

(a) It contains a weak acid and its conjugate base.

(b) It contains a weak base and its conjugate acid.

(c) It shows little change in pH on adding small amount of acid or base

(d) None of the above

Answer 1

(c) It shows little change in pH on adding small amount of acid or base

A buffer solution (more precisely, pH buffer or hydrogen ion buffer) is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. Its pH changes very little when a small or moderate amount of strong acid or base is added to it and thus it is used to prevent changes in the pH of a solution. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications.