Question

Which of the following compounds has the highest boiling point?
A. Propan – 1 – ol
B. n – butane
C. Chloroethane
D. Propanal

Answer 1

Hint- In order to find the highest boiling point in a given compound, we will use the concept as if compound to compound branching increases then in that order boiling point decreases. So, we will look amongst the given options for the compound with maximum branching.

Complete answer:
The boiling point of a compound depends upon many factors, such as pressure and intermolecular forces. If the intermolecular forces between the molecules are strong the compound's boiling point increases.

Propan-1-ol
Therefore, the conclusion is that those compounds with strong intermolecular forces will have high melting and boiling points. The hydrogen bond has stronger intermolecular forces. As branching increases boiling point decreases. Propan-1-ol has the highest boiling point because propan-1-ol contains H-bonding in their structure.
Hence, Propan – 1 – ol has the highest boiling point amongst the given options.
So, the correct answer is option A.

Note- The normal boiling point of a compound is an indicator of the volatility of that compound. The higher the boiling point, the less volatile is the compound. Conversely, the lower the boiling point, the more highly volatile is the compound. The boiling point of a compound depends upon many factors, such as pressure and intermolecular forces.