A buffer solution can be prepared from the 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)[B] (ii) , (iii)[C] (iii) , (iv)[D] (i) , (iii)

A buffer solution is typically prepared by mixing a weak acid and its conjugate base (or a weak base and its conjugate acid). This combination helps maintain a relatively stable pH when an acid or base is added to the solution.

Let's analyze each of the options:

(i) Sodium acetate (NaCH3COO) is the conjugate base of acetic acid (CH3COOH). When sodium acetate is mixed with acetic acid in water, it forms a buffer solution.

(ii) Sodium acetate (NaCH3COO) is not the conjugate base of hydrochloric acid (HCl). Therefore, mixing sodium acetate with hydrochloric acid in water does not result in a buffer solution.

(iii) Ammonium chloride (NH4Cl) is the conjugate acid of ammonia (NH3). When ammonia is mixed with ammonium chloride in water, it forms a buffer solution.

(iv) Sodium hydroxide (NaOH) is not the conjugate base of ammonia (NH3). Therefore, mixing ammonia with sodium hydroxide in water does not result in a buffer solution.

So, the correct choices for preparing buffer solutions are:

(i) Sodium acetate and acetic acid in water
(iii) Ammonia and ammonium chloride in water
The answer is [D] (i), (iii).