Final answer:
The reaction used to confirm chloride ions with silver ions is the precipitation of silver chloride (AgCl), which generates a white precipitate when silver nitrate (AgNO3) is added to a solution containing chloride ions.
Step-by-step explanation:
The chemical reaction used to confirm the presence of chloride ions with silver ions in cation analysis is the precipitation of silver chloride (AgCl). When a solution containing chloride ions is treated with a solution of silver nitrate (AgNO3), a white precipitate of silver chloride is formed, according to the balanced chemical equation:
NaCl (aq) + AgNO3 (aq) → NaNO3 (aq) + AgCl (s)
The white precipitate of AgCl is indicative of the presence of chloride ions in the solution. This test is a classic example of a precipitation reaction in qualitative analysis, commonly used to identify halide ions. If instead, a cream-colored or yellow precipitate is observed, it suggests the presence of bromide (Br⁻) or iodide (I⁻) ions respectively.