Q.13. - Organic Chemistry

Question

Question: Arrange the following compounds in order of increasing boiling point.

Step-by-Step Solution

Answer

Answer

 

The order of increasing boiling point is given below:

Step 1: Factors affecting the boiling point

Some factors which affect the boiling point of a compounds. These are mentioned below:

• As the number of carbon atoms increases, the boiling point also increases.
• As the branching increases, the surface area decreases, and hence the boiling point also decreases.

Step 2: Order of boiling point among the simplest chain compounds

The given compounds are shown below:

Given compounds

 

The simple chain compounds are octane and heptane. Octane has more carbon atoms, which means it has the highest boiling point than others. Thereafter, the boiling point of heptane would be higher than the remaining two compounds.

 

The increasing order of boiling point is illustrated below:

Order of boiling point of octane and heptane

Step 3: Order of boiling point of branched compounds

The branched compounds are 2,2,3-trimethylbutane and 2-methylhexane. The compound 2,2,3-trimethylbutane has more branching than 2-methylhexane. Thus, the surface area of 2,2,3-trimethylbutane is less than 2-methylhexane.

 

Hence, the boiling point of 2,2,3-trimethylbutane is less than 2-methylhexane. The overall order of increasing boiling point is shown below: