WAEC Chemistry 2020 Paper

Concept:$\mathrm{AgCl}$ is an insoluble precipitate, whereas $\mathrm{NaNO}_3$ remains dissolved in water.Explanation:In the reaction, solid $\mathrm{AgCl}$ forms in a mixture containing dissolved $\mathrm{NaNO}_3$.To obtain pure $\mathrm{AgCl}$, first filter the mixture to collect the solid precipitate on the filter paper.Next, wash the residue with distilled water to remove any soluble $\mathrm{NaNO}_3$ impurities.Finally, dry the washed solid to remove moisture.These steps together give a pure, dry sample of $\mathrm{AgCl}$.Answer:C. filtering, washing and drying