Question

On heating naphthalene directly changes into vapour

Answer 1

Explanation:

As the naphthalene is heated, heat energy is converted to kinetic energy. Kinetic energy increases and the molecules vibrate faster about their fixed positions and the temperature increases. Naphthalene is in solid state at any temperature below its melting point. ... The particles can only vibrate at a fixed position.

This process is called sublimation,where solid substances directly condenses to vapour without converting into liquid form. Example: ammonium chloride and camphor.

Hope this helps.