Which of the following has the highest boiling point?

The correct answer is Alkynes.Key Points

• Alkynes:-
  • ​These have the highest boiling point among the given options due to their strong intermolecular forces of attraction.
  • Alkynes have triple bonds between carbon atoms, which results in a linear shape and close packing of molecules, leading to strong van der Waals forces.
  • Alkanes have weaker intermolecular forces due to their single bonds and branched structures, resulting in lower boiling points.
  • Alkenes have double bonds, which create a kink in the molecule and reduce the surface area available for intermolecular interactions, leading to lower boiling points.
  • Free carbon dioxide is a gas at room temperature and pressure, and hence, it has the lowest boiling point among the given options.

Additional Information

• Alkanes:
  • These are hydrocarbons with single bonds between carbon atoms, and their boiling points increase with increasing chain length and molecular weight.
• Alkenes:
  • ​These are hydrocarbons with double bonds between carbon atoms, and their boiling points are lower than those of corresponding alkanes due to their lower intermolecular forces.
• Free carbon dioxide:
  • It is a gas at room temperature and pressure and is formed during respiration, combustion, and other processes.
    • It has a boiling point of -78.5^oC at standard temperature and pressure.