Mixing two layers

Step 1. Set up the sep funnel (Click on the picture to see the technique video) Place the sep funnel on an iron ring support. Check to see that the stopcock is closed. Place an Erlenmeyer flask below the sep funnel.

Step 2. Add the liquids (Click on the picture to see the technique video)   Use a fluted glass funnel to add the solution to be extracted to the sep funnel.   Use the same funnel to add the extraction solvent.

Step 3. Swirl, stopper, invert, and vent (Click on the pictures to see the technique video) Before inserting the stopper, swirl the sep funnel gently to release any gas formed upon mixing. Insert the stopper.   While holding the stopper in place, invert the sep funnel. Using the other hand, immediately open the stopcock to vent the sep funnel.

Step 4. Shake and mix the layers (Click on the pictures to see the technique video) Close the stopcock, and while holding the stopper and stopcock firmly, shake the sep funnel several times. Vent the funnel as before, then shake the sep funnel again. Vent and repeat the shaking and venting process several times. Allow the liquid layers to separate.

Why do you shake it?

Shaking allows greater area of contact between the two immiscible liquids,

resulting in faster equilibration of the solute substance(s) between the two liquids.

Organic Web Chem University of Alberta