The melting and freezing points of naphthalene


In the heating of naphthalene, the heat energy absorbed by the particles is used to overcome the forces between the particles so that the solid can turn into liquid. In the cooling curve of naphthalene, the heat loss to the surroundings is exactly balanced by the heat energy liberated as the particles attract one another to form a solid. That is why the temperature remains constant for sometime in both heating and cooling curves. The melting and freezing points of naphthalene, C10H8 are 80C. 
  • Melting point: the temperature at which a solid changes into a liquid at a particular pressure.
  • Freezing point: the temperature at which a liquid changes into a solid at a particular pressure.