There are two ores `(A_(1))` and `(A_(2))` of metal ( M ). When ore `(A_(1))` is calcined, a black solid (S) is obtained along with liberation of `CO_(2)` and water . The ore `(A_(1))` on treatment with HCl and KI gives a precipitate (P) and ioidine is liberated . The ore `(A_(2))` on roasting gives a gas (G) and metal (M) is set free. When gas (G) is passed through acidified `K_(2)Cr_(2)O_(7)` solution, it turns green. Identify `(M), (A_(1)), (A_(2)), (S),(P)` and `(G)`.

There are two ores `(A_(1))` and `(A_(2))` of metal ( M ). When ore `(

1.	There are two ores `(A_(1))` and `(A_(2))` of metal ( M ). When ore `(A_(1))` is calcined, a black solid (S) is obtained along with liberation of `CO_(2)` and water . The ore `(A_(1))` on treatment with HCl and KI gives a precipitate (P) and ioidine is liberated . The ore `(A_(2))` on roasting gives a gas (G) and metal (M) is set free. When gas (G) is passed through acidified `K_(2)Cr_(2)O_(7)` solution, it turns green. Identify `(M), (A_(1)), (A_(2)), (S),(P)` and `(G)`.
Answer» Metal ( M) is Cur and its two ores are `:` `(A_(1)) = ` malachite, `CuCO_(3) . Cu(OH)_(2)`, `(A_(2)) = ` copper glance, `Cu_(2) S` The reactions involved are `underset((A_(1)))(CuCO_(3). Cu(OH)_(2)) overset("Calcination")(rarr) underset("(S) black copper (II) oxide")(2CuO) + COuarr + H_(2)O` `CuCO_(3). Cu(OH)_(2) + 4HCl rarr 2CuCl_(2)+ CO_(2) uarr + 3H_(2)O` `2CuCl_(2)+ 4KI rarr underset("Cuprous iodide ( ppt.)") underset((P))(Cu_(2)I_(2)) + 4KCl + I_(2) uarr` `underset((A_(2))) (2Cu_(2)S) + 3O_(2)overset("Roasting ")(rarr) 2Cu_(2)O+ underset((G))(2SO_(2))` `Cu_(2)S + 2Cu_(2)O rarr underset((M))(6Cu) + SO_(2)` `K_(2)Cr_(2)O_(7) + H_(2)SO_(4) + 3SO_(2) rarrK_(2)SO_(4) + underset("(Green)") (Cr_(2)(SO_(4))_(3)) + 4H_(2)O` `:. M = Cu , (A_(1))= CuCO_(3). Cu(OH)_(2), (A_(2)) = Cu_(2)S, S= CuO, P = Cu_(2)I_(2), G= SO_(2)`