Question

In a separating funnel, the organic phase is always _______ aqueous phase.
(A) Above
(B) Below
(C) Mixed together
(D) Both a and b

Answer 1

Hint: Attempt this question by understanding the principal and working of the separating funnels. Separating funnels (also known as separation funnels), are a common fixture in chemistry labs which are used to separate immiscible liquids from their solutes. These funnels are usually glass, pear-shaped and sometimes include a stopper and a stopcock.

Complete answer:
Let us understand the principal and use of separating funnels as follows:-
-As we know that separating funnels work on the principle that immiscible liquids will separate from each other naturally along with their solutes which creates different layers of solution-solute.
-For example, if we are required to separate a nonpolar solute from a solution, it can be done by mixing it with a non-polar solvent in a separation funnel. After some time, the initial solution and non-polar solvent will separate and the solute will be in the new non-polar solvent.
-The separation of layers in the funnel based on their relative densities in which the lowest density liquid lies above the higher density liquids. Generally all organic solvents have lower density as compared to aqueous solution (or water as solvent). For example diethyl ether or pentane will always lie above the aqueous solvent which means the organic phase generally remains above the aqueous phase.

Therefore we can say that in a separating funnel, the organic phase is always (A) Above aqueous phase.

Note:
The most important exception to the case of organic solvents always being above the aqueous phase solvent are the halogenated organic solvents as they have more density than the water due to which they lie below the aqueous phase in the separating funnel.