Chemistry

When ammonia dissolves silver chloride, it forms a soluble complex ion $[\text{Ag(NH}_3)_2]^+$ that keeps the silver in solution. Adding strong acid like $\text{HNO}_3$ does two things: it protonates the ammonia ligands (removing them from the complex) and provides nitrate ions that don't form a precipitate with silver. The freed $\text{Ag}^+$ immediately re-precipitates with the chloride ions already present, forming white $\text{AgCl}$ again—so both the assertion and reason are correct, but make sure you understand why the acid breaks apart the complex.

When ammonia dissolves silver chloride, it forms a soluble complex ion $[\text{Ag(NH}_3)_2]^+$ that keeps the silver in solution. Adding strong acid like $\text{HNO}_3$ does two things: it protonates the ammonia ligands (removing them from the complex) and provides nitrate ions that don't form a precipitate with silver. The freed $\text{Ag}^+$ immediately re-precipitates with the chloride ions already present, forming white $\text{AgCl}$ again—so both the assertion and reason are correct, but make sure you understand why the acid breaks apart the complex.