This test enables to show how the state of matter can change (solid – liquid). When heated, paradichlorobenzene directly passes from the solid state to the liquid state (fusion). During this transition, temperature is kept constant because the supplied heat is used to break the bonds linking the particles. On the contrary, when cooled, students can observe the inverse phase transition, that is the transformation from the liquid state to solid state (solidification).
THEORETICAL – EXPERIMENTAL HANDBOOK