Pour a mixture of oil and coloured water in a separating funnel . Leave the funnel undisturbed for few minutes . Oil and water separate into two layers since water is heavier than the oil it will

form the lower layer . Since the separation of layers is complete, open the stop cock of the funnel and allow water to come out slowly . Close the stop cock when once all the water is collected . After that oil can be easily collected in a

beaker .