A black mineral (A) on heating in presence of air gives a gas (B). The mineral (A) on reaction with dilute `H_(2)SO_(4)` gives a gas (C) and a solution of a compound (D) on passing the gas (C) into an aqueous solution of (B), a white turbidity is obtained. The aqueous solution of (D) on reaction with potassium ferricyanide gives a blue compound (E). Identify (A) to (E) and give chemical equations for the reaction involved.

Explanation

`(A) -Ag_(2)S` (B) `-NaAg(CN)_(2)`
(C) `-Na_(2)SO_(4)` (D) `Ag`
(E) `AgCl` (F) `-Ag(NH_(3))_(2)Cl`
`underset((A))(Ag_(2)S)+4NaCN+2O_(2) rarr underset((B))(2NaAg(CN)_(2))+underset((C))(Na_(2)SO_(4))`