Answer:
1. Ethane has a higher boiling point
2. Heptyne has a higher boiling point
3. Octane has a higher boiling point
Explanation:
1. Ethane has stronger intermolecular attractions (van der Waal's forces) than ethene and so has the higher boiling point.
2. The longer (and the straighter) the chain, the greater the opportunity for intermolecular interactions, and thus the greater the boiling point. You should look up these boilig points! n-Pentane has a normal boiling point of approx. 36 ∘C ; n-heptane boils at 98 ∘C .
3. Octane has a high boiling point, because its molecule contains 8 Carbon atoms, and with increasing molecular weight of hydrocarbon its boiling temperature increases.