Q13. - Organic Chemistry

Question

Arrange the following compounds in order of increasing boiling point.

Step-by-Step Solution

Answer

The order of increasing boiling point is mentioned below:

Step 1. Factors affecting the boiling point

There are some factors by which the boiling point of the compounds is affected. These are mentioned below:

• As the number of carbon increases, the boiling point would be increased.
• As the branching increases, the surface area would be decreased, and hence the boiling point would also be decreased.

Step 2. Order of boiling point between simplest chain compounds

The given compounds are shown below:

                     Given compounds

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

 

The increasing order of boiling point is mentioned 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:

 

                          Overall order