Physical properties
Like alkanes, alkenes are colourless gases, solids and liquids that are not poisonous.
They are slightly soluble in water.
The solubility in water decrease as the carbon chain/ molar mass increase but very soluble in organic solvents like tetrachloromethane and methylbenzene.
Melting/boiling point increase as carbon chain increase.
This is because of the increase in van-der-waals /intermolecular forces as the carbon chain increase.
The 1st four straight chain alkenes (ethene,propene,but-1-ene and pent-1-ene)are gases at room temperature/ pressure.
|
Alkane |
General formula |
Melting point (oC) |
Boiling point (oC) |
State at room(298K) temperature and pressure atmosphere (101300Pa) |
|
Ethene |
CH2CH2 |
-169 |
-104 |
gas |
|
Propene |
CH3 CHCH2 |
-145 |
-47 |
gas |
|
Butene |
CH3CH2 CHCH2 |
-141 |
-26 |
gas |
|
Pent-1-ene |
CH3(CH2 CHCH2 |
-138 |
30 |
liquid |
|
Hex-1-ene |
CH3(CH2) CHCH2 |
-98 |
64 |
liquid |