Note: In the following questions a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct option out of the choices given below each question.
Assertion (A) : A solution containing a mixture of acetic acid and sodium acetate maintains a constant value of pH on addition of small amounts of acid or alkali.
Reason (R) : A solution containing a mixture of acetic acid and sodium acetate acts as a buffer solution around pH 4.75.
A buffer is a solution containing either a weak acid and its salt or a weak base and its salt, which is resistant to pH change.
A solution containing a mixture of acetic acid (weak acid) and sodium acetate (salt of weak acid) acts as a buffer solution around pH 4.75 and buffer solution always resist the change in pH on addition of small amount of acid or alkali that’s why a mixture of acetic acid and sodium acetate maintains a constant value of pH.