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.