 |
| Alkynes - Ethyne |
 |
 |
| |
| Ethyne is an unsaturated hydrocarbon with a triple bond. |
| |
| Ethyne is prepared by the action of water on calcium carbide. |
| |
|
| Preparation of ethyne |
| |
| |
 |
| |
| The gas thus produced is collected by the downward displacement of water. |
| |
| |
| It is a colourless gas with garlic-like odour when pure. It is soluble in organic solvents. It is poisonous and highly explosive. |
| |
| |
Combustion |
| |
| It burns in air with a sooty flame to produce carbon dioxide and water vapour. The flame is white, sooty and produces an extremely high temperature of 40000C. |
| |
 |
| |
Addition reactions |
| |
| Ethyne undergoes addition reactions to give saturated compounds. |
| |
| a. Chlorination |
| |
 |
| |
| b. Bromination |
| |
 |
| |
| |
Illuminant in acetylene lamps. |
| |
Oxy-acetylene torches for welding metals. |
| |
Starting material for the synthesis of organic compounds like acetaldehyde, acetic acid, ethyl alcohol and tetrachloroethane. Tetrachloroethane is a solvent and is also called Westron. |
| |
| |
| |
| |
| |