Crude oil consists of a blend of many hydrocarbons whose molecules contain from 1 to 40 carbon atoms. Since the alkanes present in crude oil have different boiling points, they can be separated. The table below gives the boiling points of some alkanes. butane has a boiling point of $0^{\circ}\text{C}$ ($M_r = 58$) pentane has a boiling point of $36^{\circ}\text{C}$ ($M_r = 72$) hexane has a boiling point of $69^{\circ}\text{C}$ ($M_r = 86$) 2-methylbutane has a boiling point of $28^{\circ}\text{C}$ ($M_r = 72$) dimethylpropane has a boiling point of $10^{\circ}\text{C}$ ($M_r = 72$) 2,3-dimethylbutane has a boiling point of $58^{\circ}\text{C}$ ($M_r = 86$) Which explanation correctly accounts for the different boiling points of the three isomers with $M_r = 72$?
- ABoiling point is dependent upon the length of the carbon chain only.
- BIncreased branching on a carbon chain increases the boiling point.
- CIncreased branching reduces the strength of the intermolecular hydrogen bonding.
- DIncreased branching reduces the strength of the intermolecular van der Waals’ forces.