Describe the differences between the boiling and melting points of different alkenes.

The boiling and melting points of alkenes increase with increasing molecular weight.

Alkenes are hydrocarbons that contain a double bond between two carbon atoms. The boiling and melting points of alkenes depend on their molecular weight and the strength of the intermolecular forces between the molecules. As the molecular weight of alkenes increases, the boiling and melting points also increase due to the increased number of electrons and the stronger London dispersion forces between the molecules.

For example, ethene (C2H4) has a boiling point of -103.7°C and a melting point of -169.2°C, while propene (C3H6) has a boiling point of -47.6°C and a melting point of -185.2°C. The difference in boiling and melting points between ethene and propene can be attributed to the increased molecular weight and the stronger intermolecular forces in propene.

Similarly, butene (C4H8) has a boiling point of -6.3°C and a melting point of -185.3°C, while pentene (C5H10) has a boiling point of 30.3°C and a melting point of -138.8°C. The trend of increasing boiling and melting points with increasing molecular weight continues for higher alkenes.

In summary, the boiling and melting points of alkenes increase with increasing molecular weight due to the increased number of electrons and the stronger intermolecular forces between the molecules.