How can you distinguish between hydrochloric acid and nitric acid?

• A. Silver nitrate produces a white precipitate with hydrochloric acid, but no reaction with nitric acid.
• B. Silver nitrate produces a blue precipitate with hydrochloric acid.
• C. Silver nitrate dissolves both acids completely.
• D. No test can distinguish them.

Answer: (A)

The key idea is a qualitative test for chloride ions. Silver ions from silver nitrate react with chloride ions to form silver chloride, which is an insoluble white precipitate. Hydrochloric acid contains chloride ions, so you see a white solid form. Nitric acid has no chloride ions, so there’s no precipitate or visible reaction. That difference lets you distinguish the two acids reliably. If a rival test were mentioned, note that other precipitates or colors would come from different halides, not from these two acids.