The correct order of increasing boiling points of the following compounds C3H7OH, C7H16 and C4H10...

Chemistry

JAMB 2010

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

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Correct Answer: Option D

Explanation

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

There is an explanation video available below.

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