Question

A buffer solution can be prepared from a mixture of:
(i) Sodium acetate and acetic acid in water
(ii) Sodium acetate and hydrochloric acid in water
(iii) Ammonia and ammonium chloride in water
(iv) Ammonia and sodium hydroxide in water

• A. (i), (ii), (iii)
• B. (ii), (iii)
• C. (iii), (iv)
• D. (i), (iii)

Answer 1

The correct option is A (i), (ii), (iii)

An acidic buffer solution consists of a weak acid (such as acetic acid) and its salt (such as sodium acetate) with a strong base (such as NaOH).

A buffer solution can be prepared from a mixture of:
(i) Sodium acetate and acetic acid in water
(ii) Sodium acetate and hydrochloric acid in water
Hydrochloric acid will partly neutralize sodium acetate to form acetic acid.
(iii) Ammonia is a weak base, and ammonium chloride is a salt. We can prepare a buffer solution by mixing ammonia and ammonium chloride. The reason is that when ammonia and ammonium chloride dissociates, then it produces a conjugate base and weak acid. Here, they produce a conjugate base, and weak acid mixes with one another and produces a buffer solution.
Hence, the option A is the correct answer.