Write balanced equation when powdered aluminium is boiled with caustic soda solution in presence of sodium nitrite.

Explanation

Al when boiled with NaOH solution, nascent `H_(2)` is produced which reduces `NO_(2)^(-)` ion to `NH_(3)`
`{:(" "Al+NaOH + H_(2)O rarr NaAlO_(2) + 3 [H] xx 2),(" "NaNO_(2)+H_(2)O rarr NaOH + HNO_(2)),(" "HNO_(2)+6H rarr NH_(3) + 2 H_(2)O),(bar(2 Al + NaOH + NaNO_(2) + H_(2)O rarr 2 NaAlO_(2) + NH_(3))):}`