CYANAMIDE, NC NH 2j the amide of normal cyanic acid, obtained by the action of ammonia on cyanogen chloride, bromide or iodide, or by the desulphurization of thio-urea with, mercuric oxide; it is generally prepared by the latter process.
Nascent hydrogen reduces cyanamide to ammonia and methylamine.
Calcium cyanamide has assumed importance in agriculture since the discovery of its economic production in the electric furnace, wherein calcium carbide takes up nitrogen from the atmosphere to form the cyanamide with the simultaneous liberation of carbon.
It appears that with soils which are not rich in humus or not deficient in lime, calcium cyanamide is almost as good, nitrogen for nitrogen, as ammonium sulphate or sodium nitrate; but it is of doubtful value with peaty soils or soils containing little lime, nor is it usefully available as a top-dressing or for storing.
Heated in a current of carbon dioxide sodamide yields caustic soda and cyanamide, and with nitrous oxide it gives sodium azoimide; it deflagrates with lead or silver nitrate and explodes with potassium chlorate.
33 28, 3329 (1901)] prepare sodium cyanamide by melting sodium with carbons or some hydrocarbon, and passing ammonia over the melt at from 400 0 -600° C. The temperature is then raised to 700°-800° C., and the sodium cyanamide in contact with the residual carbon forms sodium cyanide.
It may be obtained synthetically by the action of ammonium iodide on cyanamide, CN NH2+ NH 4 I=CN 3 H 5 HI
This diazo compound is decomposed by caustic alkalis with the formation of cyanamide and hydrazoic acid, CH4N3 N03=N3H+CN NH2+ HN03, whilst acetates and carbonates convert it into amidotetra zotic acid, H2N C?NH - N.
The first three will he treated here; for the others see Prussic Acid and Cyanamide.