The presence of impurities in a substance typically lowers its melting point and broadens its melting range. This occurs because the impurities disrupt the orderly arrangement of molecules in the crystal lattice, making it easier for the molecules to move apart and transition into a liquid state. As a result, the substance requires less energy to melt, and the melting point is reduced. The extent to which impurities affect the melting point depends on their concentration and type. The greater the amount and variety of impurities, the more significant the effect on melting point.
