The correct order of increasing boiling points of the following compounds C3H7OH, C7H16 and C4H10 is?
A
C3H7OH → C4H10 → C7H10
B
C4H10 → C7H16 → C3H7OH
C
C7H16 → C3H7OH → C4H10
D
C4H10 → C3H7OH → C7H16
Verified Correct Answer: D.
Chemical Principles & Mechanism
C3H7OH ( PROPANOL) ⇒ 97ºC
C7H16 ( HEPTANE ) ⇒ 98.42ºC ;and
C4H10 ( BUTANE ) ⇒ -1ºC
ALTERNATIVELY,
In general, the higher the molecular mass of a substance, the higher its boiling point. This is because larger molecules have more intermolecular forces of attraction, which must be overcome for the substance to boil. If the molecular masses of each of the compounds are calculated, propanol (60g/mol), heptane(100g/mol) while butane(58g/mol).
Arrangement in increasing order will be C4H10 → C3H7OH → C7H16 - Option D
Source: WAEC / JAMB / NECO Classroom Archive (Record #4505)