Calcium cyanamide
| Names | |
|---|---|
| IUPAC name
Calcium cyanamide
| |
| Other names
Cyanamide calcium salt
Lime Nitrogen Nitrolime UN 1403 | |
| Properties | |
| CaCN2 | |
| Molar mass | 80.102 g/mol |
| Appearance | White solid (Often gray or black from impurities) |
| Odor | Odorless |
| Density | 2.29 g/cm3 |
| Melting point | 1,340 °C (2,440 °F; 1,610 K) |
| Boiling point | Sublimes |
| Reacts | |
| Solubility | Insoluble in organic solvents |
| Thermochemistry | |
| Std enthalpy of
formation (ΔfH |
-351.6 kJ/mol |
| Hazards | |
| Safety data sheet | Sigma-Aldrich |
| Flash point | Non-flammable |
| Related compounds | |
| Related compounds
|
Calcium carbide Cyanamide |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Calcium cyanamide is an inorganic compound with the formula CaCN2, widely used as fertilizer in agriculture.
Contents
Properties
Chemical
Hydrolysis of CaCN2 will yield cyanamide, as well as ammonia.
- CaCN2 + H2O + CO2 → CaCO3 + H2NCN
- CaCN2 + 3 H2O → 2 NH3 + CaCO3
Fusing calcium cyanamide with sodium carbonate will give sodium cyanide.
- CaCN2 + Na2CO3 + 2C → 2 NaCN + CaO + 2 CO
Physical
Calcium cyanamide is a white (gray or black if impure) solid, which reacts with water.
Availability
Calcium cyanamide is sold as fertilizer. In some places it's hard to find.
It can also be bought from chemical suppliers.
Preparation
A common route to calcium cyanamide involves heating a mixture of calcium oxide and urea at 120-350 °C which gives calcium cyanate, followed by calcination at 7-900 °C to give calcium cyanamide.[2]
- 3 CO(NH2)2 → 3 HOCN + NH3
- CaO + 2 HOCN → Ca(OCN)2 + H2O
- Ca(OCN)2 → CaCN2 + CO2
Calcium cyanamide is obtained industrially by heating calcium carbide powder at 1,000 °C, usually in an electric furnace, while injecting nitrogen gas over the hot carbide, which is recirculated. The reaction takes several hours for completion.
Another route involves heating calcium cyanide with nitrogen gas at 600 °C for at least one hour.[3]
Reducing calcium nitride with carbon at 800-900 °C in a nitrogen atmosphere will also give calcium cyanamide.[4]
Reacting ammonia with calcium carbonate above 600 °C is another route.[5][6]
Since calcium cyanamide reacts with oxygen at high temperatures, all of these routes must be done in low of oxygen environment, and an inert gas is used.
Projects
- Make guanidine compounds
- Make sodium cyanide
- Make thiourea
- Garden fertilizer
Handling
Safety
Calcium cyanamide is harmful and should be handled with care.
It is known to cause alcohol intolerance, before or after the consumption of alcohol.
Storage
In closed containers, away from moisture.
Disposal
Can be dumped in the ground.
References
- ↑ Franck, H. H.; Hochwald, F.; Zeitschrift fuer Elektrochemie; vol. 31; (1925); p. 581 - 590
- ↑ https://www.youtube.com/watch?v=S-SOjfZ_yS4
- ↑ Franck, H.; Heimann, H.; Angewandte Chemie; vol. 44; (1931); p. 372 - 378
- ↑ Krase, H. J.; Jee, J. Y.; Journal of the American Chemical Society; vol. 46; (1924); p. 1358 - 1366
- ↑ Franklin; Journal of the American Chemical Society; vol. 44; (1922); p. 504
- ↑ Patent; Caro; Frank; DE467479; Fortschr. Teerfarbenfabr. Verw. Industriezweige; vol. 16; p. 283
