IMAT 2015 Q46 [Boiling Points]

2,2 – dimethylpropane, C(CH_3)_4, is an isomer of pentane, CH_3(CH_2)_3CH_3.

Pentane has a boiling point of 36 °C whilst the boiling point of 2,2 dimethylpropane is 10 °C.

Which statement below explains the difference in the boiling points for these two substances?

A. 2,2 – dimethylpropane has stronger intermolecular forces.

B. The molecules have different relative molecular masses.

C. Isomers have different chemical properties.

D. Pentane has permanent dipoles.

E. Longer chain, less branched molecules have stronger spontaneous/induced dipoles.