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Determination of melting point of wax 

Determination of melting point of wax  when a substance changes state, its temperature remains constant. If the substance is solid, the co...

Determination of melting point of wax 

Determination of melting point of wax


when a substance changes state, its temperature remains constant. If the substance is solid, the constant temperature at which the substance changes from solid state to liquid state at normal atmospheric pressure is called melting point of the given solid. For example, the melting point of wax is 60 ° C which means that the wax is converted from its solid state to liquid state at the temperature of 60 ° C. 


To determine the melting point of wax, take a small quantity of wax in a beaker and slowly heat the beaker by a candle or a bunsen burner. 


Note down the temperature of wax, say after every 2 minute. The temperature of wax increases initially but once it starts melting, its temperature remains constant which is called its melting point. On further improving heat the temperature remains constant at melting point until the whole of the wax is converted into liquid.



What is melting point 

The proces which involves the change in state of matter from solid to liquid by heating is called melting or fusion.  The temperature at which a solid changes into a liquid on heating at normal atmospheric pressure is called the melting point of that solid.


The heat energy supplied to the solid is absorbed by its molecules. This helps the molecules to overcome the intermolecular force of attraction as a result of which the molecules move apart each other.  The molecules acquire translatory motion in addition to vibratory motion, so, they become free to move, and thus, attain the molecular arrangement of a liquid.  

the melting point of solids which expand on melting increases with an increase in pressure while the melting point of solids which contract on melting decreases with an increase in pressure.