You were given three samples containing lipids and have been tasked to add Br2 solution until a color change is observed. Sample A required 5 mL of bromine before a visible color change. Sample B changed color almost immediately. Sample C required 12 mL while sample D needed 3 mL for a color change to be observed. Rank the samples in order of increasing degree of unsaturation and explain why?

Answer 1

The way this question is worded is a bit confusing. When you say color change you don't make it clear whether it is the Br2 water that is changing color or the lipid that is changing color. Here is the way I understand the statement. You will add Br2 water (which is brown-red) to the solution. If the solution is saturated the Br2 water color remains and changes the solution immediately. If a degree of un- saturation is there the Br2 color goes away. Another thing is you said 3 samples but you listed 4.
So, sample A has unsaturation. Either double or triple bonds. Sample B has none. Sample C has the most unsaturation and sample D is between A and B. Unsaturation can be in the form of double bonds or triple bonds.