An orange coloured solid (A) on heating left a green residue (B) with evolution of a colourless gas (C) and water vapour. When the gas (C) is passed over heated Mg a white solid (D) is formed. The soid (D) on boiling with water produces a gas (E), that forms a dense white fumes when comes in contact with HCI. Identify (A) to (E) from the options given below.

An orange coloured solid (A) on heating left a green residue (B) with

1.	An orange coloured solid (A) on heating left a green residue (B) with evolution of a colourless gas (C) and water vapour. When the gas (C) is passed over heated Mg a white solid (D) is formed. The soid (D) on boiling with water produces a gas (E), that forms a dense white fumes when comes in contact with HCI. Identify (A) to (E) from the options given below.
Answer» `{:(A,B,C,D,E),(Cr_2O_3, CrO_3, Mg_3N_2, N_2, NH_3):}` `{:(A,B,C,D,E),(Cr_2O_3, (NH_4)_(2)Cr_2O_7, N_2, Mg_3N_2, NH_3):}` `{:(A,B,C,D,E),((NH_4)_(2)Cr_2O_7,Cr_2O_3,N_2, Mg_3N_2, NH_3):}` `{:(A,B,C,D,E),((NH_4)_(2)Cr_2O_7,Cr_2O_3,N_2, CrO_2Cl_2, NH_3):}` SOLUTION :The compounds are, As the gas .E. forms a dense white fumes with `HCl`, so it might be `NH_3`.As it is formed by boiling .D. with water, so .D. is `Mg_3N_2` and .C. is `N_2` gas. Hence, the organge coloured solid .A. is `(NH_4)_2 Cr_2 O_7` which on heating leaves the RESIDUE `Cr_2O_3(B)`. `underset("Orange")underset((A))((NH_4)_(2)) Cr_2O_7 rarr underset(("Green"))underset((B))(Cr_2O_3) + 4H_2O UARR + underset((C))(N_2) uarr` `3Mg + N_2 rarr underset((D))(Mg_3N_2) ` `3Mg_3N_2 + 6H_2O to 3Mg(OH)_(2) + overset((E))(2NH_3) uarr` `underset((E))(NH_3) + HCl rarr underset(("Dense white fumes"))(NH_4Cl)`.