Question

Octane has a higher boiling point than pentane because _____.

1)octane has a larger number of carbon atoms than propane

2)octane is a saturated hydrocarbon, and pentane is an unsaturated hydrocarbon

3)octane is a straight-chain alkane, and pentane is a branched-chain alkane

4)octane has a smaller number of carbon atoms than propane

Answer 1

Hii..
Your ans is 1)Octane has larger number of carbon atoms than pentane...
so more will b the intermolecular force and hence more the boiling point..

hope this helps!

Answer 2

ANSWER:

"Octane has a higher boiling point" than pentane because 1) "octane has a larger number of carbon atoms" than propane.  

EXPLANATION:

         Also, in octane the atoms are very closely packed hence the intermolecular force between the atoms is much more than that of the pentane which means the boiling point of Octane is much higher than that of the pentane.

Pentane has loosely packed atoms which make it easier to boil because of the low boiling point.