Answer: A volatile substance can be stated as a substance which readily evaporates at normal temperatures. Volatile as a term is connected with liquid generally. The rate at which vaporisation of a substance occurs under a particular set of conditions is called the evaporation rate. The non-volatile substances have a low vapour pressure and a boiling point that is quite high. The volatile nature of a substance is a physical property that depends on the intermolecular forces that hold the molecules or atoms of a particular substance.