Temperature varies in boiling point from substance to substance as the crystallization of the first solid mineral starts to melt where as melting of the last mineral ends. The range of melting point slightly differs from 99.9% purity of compound (1-2 Co) to 98% purity of compound (2-4 Co). Therefore, the melting point can be determined in order to tentatively find out the pure compound in its solid state. The presence of of even low volume of impurity can decrease melting point of compound by a few degrees, thus increasing temperature of melting point.
Why is it so efficacious ?
The reason for its effectiveness can be delineated easily as the presence of impurities effect defects in crystal lattice. It is quite easy to stop the strong intermolecular interaction between molecules. To figure out this concept, one can conjecture the crystal structure of an mineral solid such as a Steroid powder seeming as a brick wall. Every brick in the wall depicts organic molecules, where as mortar clings bricks firmly is the example of intermolecular interactive force. In the pure organic crystal structure, every molecule are similar, thus it holds together in an organized, and orderly manner. In this order, the interactive forces between the molecules are enhanced.
The brick wall (on the left) reflect the perfect crystal structure. all of the bricks (the molecules) are corresponding, and it sticks tightly in three-dimensional and orderly array. But with the conjugation of two different organic molecules, the crystal will be impure.
These varying molecules will not be befitting in a knitted manner to form an orderly array. Thinking by analogy of brick wall, one can visualize making efforts for placing a soccer ball into the brick wall. There is nothing but discordance with a soccer ball, because it differs in shape and size therefore can not fit well with mortar
It causes a flaws in the structure of the brick wall (a flaw in the crystal structure), therefore the structure becomes weak, and it can easily be surmounted by an input of energy. Less heating is required to melt down the mixture than required to melt the pure structure. Less heat means a low temperature; thereby, an impure solid mineral melts at a lower temperature than the pure solid mineral. The solid mineral with impurities also melts over a wide range of temperature, because of regions within the crystal that possesses different level of the impurity, and the different number of flaws in the crystal brick wall.
Inter Steroids Pharmaceutical Co. Ltd. has corroborated the efficacy, accuracy and Science for efficiently conducting melting point test.