Acetylene is a colourless gas with a pleasant odour. It usually contains traces of phosphine that cause an unpleasant garliclike odour. It is stored in a high pressure cylinder filled with a porous material and containing acetone. Acetylene can be decomposed to its elements with the liberation of heat. It can decompose spontaneously of pressure exceeds 15 PSIG.
Acetylene is manufactured by the reaction of water with calcium carbide. It is also manufactured by thermal cracking of hydrocarbons, or by partial combustion of methane and oxygen.
Formula - C2H2
Molecular Weight - 26.04
Physical Properties of Acetylene
- It is a colorless and flammable gas.
- It has a ginger like odor · Acetylene of 100% purity is
odorless.
- Formula : C2H2
- Specific Heat : 10.53 BTU/lbmol-deg F@ 70 deg. F
- Specific Gravity : .920
- Gas Density : .0677 lb/ ft3 @ 70 deg. F. 14.7 PSIA
- Psa t: 586.2 psia @ 70 deg F
- Liquid Density : 23.61 lb/ ft3 @ 70 deg F
- Boiling Point : Temperature: -120.6 deg. F ( deg. C)
- Critical Point :Temperature: 95.36 deg. F, Pressure: 897.8 PSIA
- Melting Point : Temperature: -113.0 deg. F, Pressure: 18.5 PSIA
- Flammable Limits : 2.3-100%
- Specific Gravity : 0.91@70F
- Together with air it forms an explosive mixture.
- Thermal decomposition produces carbon monoxide that is poisonous.
- It possess a reactive triple bond between carbon and carbon.






