Question

An inorganic compound (A) shows the following reactions.

(i) It is white solid and exists as dimmer; gives fumes of (B) with wet air.

(ii) It sublimes on 180°C and forms monomer if heated to 400° C.

(iii) Its aqueous solution turns blue litmus to red.

(iv) Addition of NH4 OH and NaOH separately to a solution of (A) gives white ppt. which is however soluble in excess of NaOH.

Answer 1

(i) (A) is a characteristic dimerized compound which sublimes on 180°C and forms monomer if heated to 400° C and thus, (A) is (AlCl3 ) 2 or Al2 Cl6

(iii) Its solution in water is acidic due to hydrolysis

(iv) (A) gives white ppt. with NH4 OH, soluble in excess of NaOH.