An aspirin sample is synthesized from salicylic acid and acetic anhydride and then tested for purity using an iron(III) chloride solution. The resulting solution is a deep purple color. What caused the purple color?
The iron(III) chloride solution reacted with a unreacted salicylic acid, forming the purple iron(III) salicylate complex.
The iron(III) chloride solution reacted with the synthesized aspirin molecule, forming the purple iron(III) aspirin complex.
The iron(III) chloride solution reacted with a unreacted acetic anhydride, forming the purple iron(III) anhydride complex.
The iron(III) chloride solution is the final step in the purification of the synthesized aspirin. It will react with any unreacted salicylic acid or acetic anhydride to ensure the final sample of aspirin is pure.