Which of the following silver halides is insoluble in liquor ammonia ?

Options

A. AgF
B. AgCI
C. AgBr
D. AgI

Answer

D

Explanation

When we add liqour ammonia, the `Ag^(+)` ions (if present in sufficient concentration) may react with `NH_(3)` molecules to give the liner diammine silver (I) ion:
`Ag^(+) (aq) + 2NH_(3) (aq) rarr [Ag(NH_(3))_(2)]^(+)`
This tends to shift the following equilibrium
`Ag X (s)hArr(aq) + X^(-) (aq)`
towads right making AgX soluble. The precipitate of AgCI is very readily soluble, silver bromide is only slightly soluble, and silver iodide is insoluble in dilute ammonia. This happens because AgCI has the highest `K_(sp)`, thereby providing large enough concentration of `Ag^(+)` ions to form complex with `NH_(3)` whilst AgI has the lowest `K_(sp)`, thereby providing a very low conc. of `Ag^(+)` ions which is unable to form complex with `NH_(3)`