Question

Which of the following explains why 1-pentyne has a slightly higher boiling point than 1-pentene? Group of answer choices The C-C triple bond in 1-pentyne is more polar than the C-C double bond in 1-pentene. 1-Pentyne has more carbons than 1-pentene. 1-Pentyne has more carbons per hydrogen than 1-pentene. 1-Pentyne is linear while 1-pentene is trigonal planar.

Answer 1

Answer:

Correct options: (1) The C-C triple bond in 1-pentyne is more polar than the C-C double bond in 1-pentene and (2) 1-Pentyne is linear while 1-pentene is trigonal planar.

Explanation:

• 1-pentyne has linear structure due to presence of triple bond. Therefore, 1-pentyne molecule cam come closer to each other as compared to 1-pentene (trigonal planar) and exert more van der waal intermolecular force.
• Presence of more number of pi-electrons in triple bond makes 1-pentyne more polarizable. Hence van der waal force is more stronger in 1-pentyne as compared to 1-pentene.
• Van der waal force is not so strong as compared to dipole-dipole force or H-bonding.
• Therefore 1-pentyne has slightly higher boiling point than 1-pentene.

Correct options: (1) The C-C triple bond in 1-pentyne is more polar than the C-C double bond in 1-pentene and (2) 1-Pentyne is linear while 1-pentene is trigonal planar