compare the boiling points of 1 - pentyne and 1 - octyne. compare the vapor pressure curves of 1 - butene…

Explanation:

Step1: Consider intermolecular forces

Larger molecules have stronger London - dispersion forces.

Step2: Analyze 1 - pentyne and 1 - octyne

1 - Octyne has more carbon atoms (8) than 1 - pentyne (5). So 1 - octyne has stronger London - dispersion forces. Stronger intermolecular forces mean a higher boiling point. Thus, 1 - octyne has a higher boiling point than 1 - pentyne.

Step3: Analyze 1 - butene and 1 - heptene

1 - Heptene has more carbon atoms (7) than 1 - butene (4). So 1 - heptene has stronger London - dispersion forces. Vapor pressure is inversely related to intermolecular forces. So 1 - butene, with weaker intermolecular forces, has a higher vapor pressure at a given temperature, and its vapor - pressure curve will be above that of 1 - heptene.

Answer:

1 - Octyne has a higher boiling point than 1 - pentyne because it has stronger London - dispersion forces due to more carbon atoms. The vapor - pressure curve of 1 - butene is above that of 1 - heptene because 1 - butene has weaker intermolecular forces and thus higher vapor pressure at a given temperature.