Ordering ethane, propane and butane from lowest to highest boiling point gives:
APropane, ethane, butane
BButane, ethane, propane
CEthane, propane, butane
DButane, propane, ethane
Answer & Solution
Correct answer: C. Ethane, propane, butane
1. All three are nonpolar hydrocarbons, so only dispersion forces are in play.
2. Dispersion strength grows with molecular size and surface area.
3. The ordering from lowest to highest boiling point is therefore ethane, then propane, then butane.
4. Each extra carbon adds to the contact area between molecules.
_Source: OpenStax Chemistry 2e (CC BY 4.0), Ch 10 'Liquids and Solids', sections 10.1-10.6_
Keep practising Intermolecular Forces, Liquids and Solids
Browse all Intermolecular Forces, Liquids and Solids questions for AP Chemistry, or explore more Chemistry topics.
Related questions
Complete the dispersion ruleMatch each term to its meaningTrue or false: intermolecular forcesInside a molecule or between?Which boils at the higher point?Dispersion forces are present in condensed phases:Dispersion forces become significant only when molecules are:A solid forms from a liquid when the molecules no longer have enough kinetic energy to ove