Illustrated Guide to Home Chemistry Experiments

Chapter 6 Laboratory: Separating Mixtures 107

RQEWEvI UESTIOnS

q 1 : The colors of the two layers after agitating and settling make it clear that most of the iodine was extracted from the aqueous
layer into the organic layer, but that does not explain the color change from orange in the aqueous layer to magenta in the organic
layer. Use the Internet to research the cause for this color change.

q: 2 You are running a solvent extraction to isolate the products of a synthesis, using an aqueous layer and an organic layer. After
agitation and settling, the two layers are of very similar appearance. You know that the organic layer contains your product and the
aqueous layer is the waste layer, but you are not 100% certain which layer is which. What simple test might you perform to determine
which is the organic layer?

Layer Appearance

A. Aqueous iodine solution

B. Organic layer (before agitation)

C. Mixed layers (after agitation)

D. Aqueous layer (after settling)

E. Organic layer (after settling)

F. Aqueous layer (after second extraction)

G. Organic layer (after second extraction)

TABLE 6-4: Solvent extraction of iodine—observed data