Provide an example of the boiling and melting points of different alkynes.

The boiling and melting points of alkynes increase with the number of carbon atoms in the molecule.

Alkynes are hydrocarbons that contain a triple bond between two carbon atoms. The boiling and melting points of alkynes increase with the number of carbon atoms in the molecule. This is due to the increased strength of the intermolecular forces between the molecules as the size of the molecule increases.

For example, ethyne (C2H2) has a boiling point of -84°C and a melting point of -80°C, while but-1-yne (C4H6) has a boiling point of 8°C and a melting point of -117°C. The higher boiling and melting points of but-1-yne are due to the increased number of electrons in the molecule, which leads to stronger London dispersion forces between the molecules.

Similarly, pent-1-yne (C5H8) has a boiling point of 36°C and a melting point of -80°C, while hex-1-yne (C6H10) has a boiling point of 69°C and a melting point of -30°C. Again, the increased size of the molecule leads to stronger intermolecular forces and higher boiling and melting points.

Overall, the boiling and melting points of alkynes increase with the number of carbon atoms in the molecule due to the increased strength of intermolecular forces between the molecules.