How to Use a Separatory Funnel

Inspect the separatory funnel and close the stopcock by positioning it horizontally. Mount the funnel in an iron ring stand equipped with rubber tubing to prevent glass scratching.

Use a funnel to pour the two immiscible liquids (one organic, one aqueous) into the separatory funnel from the top. The aqueous layer is dyed blue with copper II sulfate to distinguish the layers.

Add a single drop of water to the funnel and observe which layer it enters to confirm which layer is more dense. In this case, the water drop enters the bottom layer, identifying it as the aqueous layer.

Hold the stopper firmly closed at the top, invert the funnel upside down to mix the liquids thoroughly, and periodically open the stopcock toward the fume hood to release pressure buildup from gases.

Place the funnel back in the ring stand and allow the two immiscible layers to separate. This separation may take seconds or longer depending on the liquids being used.

Remove the stopper from the top of the funnel to prevent vacuum formation. Open the stopcock carefully and allow the denser bottom layer to drain into a collection container, closing the stopcock promptly when the layers begin to mix.

Pour the remaining top layer into a separate container through the opening at the top of the funnel. The two immiscible layers are now completely separated into distinct containers.