Question

How can melting point determinations be used in identifying and characterizing unknown compounds?

Answer 1

Hint: We know that melting point is the temperature at which a solid changes to its liquid state. Melting points are used to know the purity of a substance. When heat is supplied to a solid substance, the melting point reaches when heated gradually. On providing excess heat, the solid undergoes conversion to liquid without any temperature change.

Complete step by step answer:
Melting point determination of different elements helps to understand the purity of a substance. A pure substance has a melting range of one or two degrees but the range of melting of impure substances is much higher than the pure substance. The melting point also depends on the structure of the molecule. In melting point determination of organic compounds can be done by small experiments such as Thiele tube method.

Additional Information:
There are many factors that affect the melting point of organic compounds such as the size of the molecule, force of attraction, impurities. If the packing of the particles of a compound is very high, then the melting point of the compound is very high. Also, if the force of attraction between the particles is high, then the melting point of the compound is high. The presence of impurities also raises the melting point of the compound.

Note: It is to be noted that the melting point determination of organic compounds helps us to know the physical and chemical properties of the compound. Different compounds have different melting points because of their different structure and force of attraction.