Is Matter Around Us Pure? — Science STD 9 — Question

The mixture of water, kerosene and sand is filtered with the help of filter paper first. Sand remains as residue on the filter paper while mixture of water and kerosene is obtained as filtrate .The mixture of water and kerosene is then put in separating funnel and allowed to stand for some time. The mixture separates into two layers according to the difference in the densities of water and kerosene. Water is heavier than kerosene. So, water forms lower layer while kerosene forms upper layer. On opening the stop clock of separating funnel, the lower layer of water comes out first and collected in beaker leaving behind kerosene in the separating funnel.