Question

what type of alcohol is isoborneol?
monoterpenoid alcohol

what type of carbonyl compound is camphor?
bicyclic terpenoid ketone

isoborneol melts at 208 °c. why is the melting point of camphor lower (think inter-molecular forces)?

Explanation:

Step1: Analyze intermolecular forces

Isoborneol has an -OH group which can form hydrogen bonds. Hydrogen bonds are strong intermolecular forces. Camphor has a carbonyl group (C = O). The intermolecular forces in camphor are dipole - dipole forces (due to the polar C = O bond).

Step2: Compare strength of forces

Hydrogen bonds are stronger than dipole - dipole forces. Stronger intermolecular forces require more energy to break, resulting in a higher melting point. Since isoborneol has stronger intermolecular forces (hydrogen bonds) compared to camphor (dipole - dipole forces), camphor has a lower melting point.

Answer:

Camphor has a lower melting point than isoborneol because isoborneol can form hydrogen bonds (stronger intermolecular forces) due to its -OH group, while camphor has only dipole - dipole forces (weaker) due to its carbonyl group.