Question

Assume that during an extraction experiment you have lost track of which layer is the aqueous layer. How could you determine which layer is which by the use of a simple test?

Answer 1

you got it right in the search. Organic Chem

Answer 2

The shape of the miniscus is often a good way to tell.

Answer 3

Could you elaborate Dr Russ?

Answer 4

The aqueous phase has a concave meniscus. The majority of organic phases have a convex or flat meniscus. Thus by looking at the interface between the two phases it is often easy to decide which is which. With experience you can tell by letting a little out of the bottom of the separating funnel in to the tube below the tap. The aqueous phase tends to form a drop which stays put while an organic phase immediately runs out of the tube.

If the two phases are in a separating funnel then drop a little of the phases on to a waxed/greased surface. The aqueous phase forms blobs while the organic phase tends to spread out.