Question

Arrange the alkanes in each set in order of increasing boiling point. (a) 2-Methylbutane, 2,2-dimethylpropane, and pentane (b) 3,3 -Dimethylheptane, \(2,2,4\)-trimethylhexane, and nonane

Short answer

Question: Arrange the given alkanes in increasing boiling point order. Sets of alkanes: a) 2-Methylbutane, 2,2-dimethylpropane, and pentane b) 3,3-Dimethylheptane, 2,2,4-trimethylhexane, and nonane Answer: a) 2,2-dimethylpropane, 2-methylbutane, pentane b) 2,2,4-trimethylhexane, 3,3-dimethylheptane, nonane

Step-by-step solution

1. Examine the alkane structures

In this set, we have three alkanes: - 2-Methylbutane has 5 carbon atoms and one branching. - 2,2-dimethylpropane has 5 carbon atoms and two branchings. - Pentane has 5 carbon atoms and no branching.

2. Arrange by boiling points

Due to having similar molecular weights, the boiling points will primarily depend on the surface area of these alkanes. Alkanes with more branching will have a smaller surface area and therefore a lower boiling point. So the order of increasing boiling points is as follows: 1. 2,2-dimethylpropane 2. 2-methylbutane 3. Pentane Set (b) - 3,3-Dimethylheptane, 2,2,4-trimethylhexane, and nonane We will follow the same procedure for this set of alkanes.

1. Examine the alkane structures

In this set, we have three alkanes: - 3,3-Dimethylheptane has 9 carbon atoms and one branching - 2,2,4-trimethylhexane has 9 carbon atoms and three branchings - Nonane has 9 carbon atoms and no branching

2. Arrange by boiling points

Again, all three alkanes have the same molecular weight, so we'll focus on the surface area to determine the boiling points. The order of increasing boiling points will be: 1. 2,2,4-trimethylhexane 2. 3,3-dimethylheptane 3. Nonane In conclusion, the order of boiling points for set (a) is 2,2-dimethylpropane, 2-methylbutane, and pentane, while the order for set (b) is 2,2,4-trimethylhexane, 3,3-dimethylheptane, and nonane.