Question

Which among the following are true?

• A. Vander waal forces are responsible for the formation of molecular crystals
• B. Branching lowers the boiling points of isomeric organic compounds
• C. In graphite. Vander waal forces act between the carbon layers
• D. In Diamond. Vander waal forces act between the carbon layers

Answer 1

Answer: (A), (B), (C)

The correct options are
A

Vander waal forces are responsible for the formation of molecular crystals

B

Branching lowers the boiling points of isomeric organic compounds

C

In graphite. Vander waal forces act between the carbon layers

In diamond, there are covalent bonds present between the carbon atoms. In graphite, the layers are held together by Van der Waals forces.
Molecularcrystals are solids where the building units are molecules held together by Van der Waals forces. In ionic solids, it is the electrostatic force.
As branching increases, the surface area decreases and hence the intermolecular forces of attraction which ultimately results in a decrease of boiling point.