Zinc Nitride, Zn₃N₂

Zinc Nitride, Zn₃N₂, is obtained as a grey powder by heating zinc amide to a red heat -

3Zn (NH₄)₂ = Zn₃N₂+4NH₄. Water acts so violently on it that it incandesces -

Zn₃N₂ + 6H₂O = 3Zn(OH)₂+2NH₄.

Small quantities of zinc nitride are formed between the poles of an electric arc maintained between zinc electrodes in an atmosphere of nitrogen, and when zinc is heated strongly in nitrogen it is covered by a grey deposit that gives off a corresponding amount of ammonia with molten potassium hydroxide.

Zinc dust absorbs nitrogen when heated in either nitrogen or ammonia. The most favourable temperature for absorption seems to be 600° C., but since zinc nitride begins to decompose below this temperature, the zinc is only incompletely converted into nitride.14 Distilled zinc may contain small quantities of nitride; about 4 per cent.

of zinc nitride, determined by the ammonia liberated by boiling with aqueous potassium hydroxide, was found in some zinc dusts, and commercial fused zincs may contain traces of it.

Zinc nitride has been said to be produced in small quantities by heating zinc and calcium carbide in the presence of air, and when zinc is dissolved by electro solution - using an ammonium salt as solvent.