Calcium burns in nitrogen to produce a white powder which dissolves in sufficient water to produce a gas (A) and an alkaline solution . The solution on exposure to air produces a thin solid layer of (B) on the surface . Identify the compounds A and B .

Calcium burns in nitrogen to produce a white powder which dissolves in

1.	Calcium burns in nitrogen to produce a white powder which dissolves in sufficient water to produce a gas (A) and an alkaline solution . The solution on exposure to air produces a thin solid layer of (B) on the surface . Identify the compounds A and B .
Answer» Solution :Ca burns in air to form CAO and `Ca_(3)N_(2)`. `2 Ca + O_(2) overset(DELTA)(to) 2 CaO , 3 Ca + N_(2) overset(Delta)(to) Ca_(3)N_(2)` Calcium nitride on HYDROLYSIS with `H_(2)O` gives AMMONIA (A) `Ca_(3) N_(2) + 6 H_(2)O to 3 Ca(OH)_(2) + underset(A) (2 N)H_(3)` The alkaline solution of `Ca(OH)_(2)` thus formed reacts with `CO_(2)` present in the air to form `CaCO_(3)` which being INSOLUBLE forms a thin solid layer on the surface . `Ca(OH)_(2) + CO_(2) to underset(B)(CaC)O_(3) + H_(2)O` Thus , A = `NH_(3)` and `B = CaCO_(3)` (white powder)