1. Question 5 Rank the following compounds from lowest to highest boiling point. CH,OH CH,
H2O C2Hs O CH4
Solution
Correct Option is (e)
CH 4 < C 2 H 6 < CH 3 OH < H 2 O
C 2 H 6 has strong London dispersion forces. CH 4 has weak intermolecular forces, thus have low
B. P than C 2 H 6 . Polar groups like OH, NH, COOH etc. increase intermolecular attraction and
boiling point.
Water has such a high boiling point because it can form hydrogen bonds, the most powerful type
of intermolecular attraction. Methanol can also form hydrogen bonds because of its alcohol
group, but not as many as water.
Thank you