Final answer:
Octane has the highest boiling point among the given hydrocarbons due to its higher molecular mass and consequent stronger London dispersion forces.
Step-by-step explanation:
The student asked which of the hydrocarbons hexane, butane, propane, octane, and pentane has the highest boiling point. The compounds in question are all alkanes and their boiling points increase with molecular mass due to stronger London dispersion forces. The compound with the highest molecular mass among the options given is octane. Therefore, by using molecular mass as our basis for comparison, we can conclude that octane would have the highest boiling point amongst the group.
The order of increasing boiling points would be:
- Propane (C3H8)
- Butane (C4H10)
- Pentane (C5H12)
- Hexane (C6H14)
- Octane (C8H18)