Physical Properties of Alkynes
Physical State and Odour of Alkynes
The first three members of alkyne family — ethyne, propyne and butyne are colourless gases, the next eight members are liquids and the higher ones are solids. Except for ethyne, which has characteristic smell, all members are odourless.
Boiling Points of Alkynes
The boiling point of alkynes increases with molar mass. Among hydrocarbons, alkynes have higher boiling point than alkenes and alkanes because of the presence of triple bond in alkynes.
Solubility of Alkynes
Alkynes like alkanes and alkenes are non-polar; therefore, they are insoluble in water but readily dissolve in organic solvents such as ether, carbon tetrachloride and benzene.
Density of Alkynes
The density of alkynes increases with mass. All alkynes are lighter than water.