[bamster]

water when one is extracting and organic compound from an aqueous solution in a seperatory funnel?

[bromidewind]

The difference in density allows you to separate out the components. DCM is much more dense than water, so any compounds that are dissolved in DCM will stay below the aqueous layer. This is extremely useful in acid/base reactions.

[xiaojunzhang]

yeah,that's true!

[Med90]

differences in the density of solvents allow the separation of two phases..Organic solvents like CH2Cl2, CHCl3 having higher density than water remains at the lower part of separatory funnel which can be easily collected via the stopcock at the end of funnel.

*extracting solvent shouldn't be miscible with water, otherwise there will be no separation despite of differences in their densities