Question:
Aflask contains a mixture of isohexaneand 3-methylpentane. One of the liquids boils at $63^{\circ} \mathrm{C}$ while the other boils at $60^{\circ} \mathrm{C}$. What is the best way to separate the two liquids and which one will be distilled out first?
Correct Option: 1
Solution:
Liquid having lower boiling point comes out first in fractional distillation. Simple distillation can't be used as boiling point difference is very small.
3-Methylpantane will show greater boiling point $\left(63^{\circ} \mathrm{C}\right)$ comparatives to isohexane due to symmetrical structure. Therefore isohexane distilled out first.