Question

Which among butane, propane and pentane will have the highest boiling point? Explain.​

Answer 1

Explanation:

With straight-chain molecules, as the number of carbons increase the boiling point also increases because there are more carbons that can interact and form London dispersion attractions. So, pentane (5 carbons) will have a higher boiling point than butane (4 carbons).

Answer 2

Answer:

Pentane>Butane>Propane.

Explanation:

Larger molecules have stronger van der waal's forces between them. Hence larger the molecules larger the boiling point. In homologous series on the addition of each carbon, the boiling point increases by 20-30°c according to the rule of thumb. Also, a straight-chain alkane has a higher boiling point than branched alkane because of the greater surface area in contact in the straight chain.