HU CRUDE Leftover salicylic acid PURE Still contains salicylic acid Major peaks for salicylic acid 70 76 74 72 4. What color does iron (III) chloride turn a solution of aspirin if it contains traces of salicylic acid? See: Aspirin Purity Testing 5. How were you able to tell the crude aspirin from the pure aspirin in the video? 6. What region do most of the signals show up in the NMR of pure aspirin, crude aspirin and salicylic acid? 7. How many aromatic signals were visible for the pure aspirin