Question

A metal salt solution gives a yellow precipitate with silver nitrate. The precipitate dissolves in dilute nitric acid as well as in ammonium hydroxide. The solution contains
A. bromde ions
B. iodide ions
C. phosphate ions
D. chromate ions

Answer 1

Correct Answer - C
`Ag_(3)PO_(4)` is yellow precipitate which is soluble in both dilute ammonia solution and dilute `HNO_(3)`.
`HPO_(4)^(2-)+3Ag^(+) to Ag_(3)PO_(4) darr +H^(+)`
`Ag_(3)PO_(4)+2H^(+) to H_(2)PO_(4^(-)) darr+2Ag^(+)`,
`Ag_(3)PO_(4)darr +6NH_(3) to 3[Ag(NH_(3))_(2)]^(+) +PO_(4)^(3-)`
Pale yellow precipitate of AgBr is not soluble in dilute `HNO_(3)`, bright yellow precipitate of Agl is not soluble in both, `Ag_(2)CrO_(4)` is obtained as red precipitate.