Question

The correct order of increasing boiling points of the following compounds is: Pentan-1-ol, n-Butane, Pentanal, Ethoxyethane

• A. Ethoxyethane, Pentanal, n-Butane, Pentan-1-ol
• B. Pentanal, n-Butane, Ethoxyethane, Pentan-1-ol
• C. n-Butane, Pentanal, Ethoxyethane, Pentan-1-ol
• D. n-Butane, Ethoxyethane, Pentanal, Pentan-1-ol

Answer 1

The Correct Option is D

To determine the correct order of increasing boiling points among n-Butane, Ethoxyethane (Diethyl ether), Pentanal, and Pentan-1-ol, we have to consider intermolecular forces which include Van der Waals forces, dipole-dipole interactions, and hydrogen bonding. 

• n-Butane: It is an alkane with weak Van der Waals forces and no significant dipole moments or hydrogen bonding, resulting in a low boiling point.
• Ethoxyethane (Diethyl ether): It has stronger Van der Waals forces than n-butane and can participate in dipole-dipole interactions because of its ether group, leading to a higher boiling point compared to n-butane.
• Pentanal: As an aldehyde, it possesses a polar carbonyl group, which means it exhibits stronger dipole-dipole interactions compared to ethoxyethane, thus having a higher boiling point than ethoxyethane.
• Pentan-1-ol: This compound has the ability to form hydrogen bonds due to the presence of a hydroxyl group (-OH), which drastically increases its boiling point compared to the others.

Thus, the order of increasing boiling points is: n-Butane, Ethoxyethane, Pentanal, Pentan-1-ol.