Q1 of 59 Page 101

How is a mixture of common salt, oil and water separated? You can use a combination of different methods.

Common salt has polar nature (actually ionic) and water is a polar solvent whereas oil is non-polar so salt gets dissolved only with water. (Like dissolves like)


a) We know that oil and water are immiscible liquids and salt is dissolved only in water so we make use of separating funnel. Water along with dissolved salt is present in the lower layer while oil forms the upper layer. On opening the stop-cock, water runs out while oil remains which can then be removed.


b) Now, water boils at 100°C while common salt doesn’t so they can easily be separated with boiling or vaporisation technique.


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