a gas a obtained by heating aluminium with sodium hydroxide was passed over a black solid, b at 773K when a grey metal C and colourless liquid D is obtained. The metal C displaces copper from copper sulphate solution and becomes passive on treatment with HNO3. Identify A, B, C and D. explain all the reactions

a gas a obtained by heating aluminium with sodium hydroxide was passed

1.	a gas a obtained by heating aluminium with sodium hydroxide was passed over a black solid, b at 773K when a grey metal C and colourless liquid D is obtained. The metal C displaces copper from copper sulphate solution and becomes passive on treatment with HNO3. Identify A, B, C and D. explain all the reactions
Answer» a gas a obtained by heating aluminium with sodium hydroxide was passed over a black solid, b at 773K when a grey metal C and colourless liquid D is obtained. The metal C displaces copper from copper sulphate solution and becomes passive on treatment with HNO3. Identify A, B, C and D. explain all the reactions