Answer: A. Mixing aqueous \(\text{AgNO}_3\) and aqueous \(\text{NaCl}\) gives a precipitation reaction: \(\text{AgNO}_3 + \text{NaCl} \rightarrow \text{AgCl(s)} + \text{NaNO}_3\). The silver chloride formed is insoluble; it appears as a white solid suspended in the solution.
To get a pure sample of the insoluble AgCl, filter the mixture. The AgCl stays as residue on the filter paper while \(\text{NaNO}_3\) (soluble) passes through as filtrate.
Evaporation (B) would leave both AgCl and \(\text{NaNO}_3\) together — not pure. Crystallisation (C) is for dissolved soluble salts, not pre-formed precipitates. Paper chromatography (D) separates dissolved coloured substances, not solids from solutions.
Every O Level Pure Chemistry TYS MCQ solution video, plus full Sec 3 / Sec 4 topic recordings.
Find out more