1 By convention a normal lens on a 35mm film camera (and thus a full-frame EOS digital SLR) has a focal length of 50mm or so. 2  A lens with a focal length of 35mm is considered ânormalâ for a cropped-frame EF-S camera.
Aspirin. One of the best known aromatic acetates is acetylsalicylic acid, or aspirin, which is prepared by the esterification of the phenolic hydroxyl group of salicylic acid. Aspirin possesses a number of properties that make it the most often recommended drug.
Best Answer: Ferric chloride [this is an old name, new accepted name is iron (III) chloride], forms a complex with salicylic acid, which is one of the reactants in the preparation of aspirin. The complex is purple, so if adding iron (III) chloride turns the aspirin purple, there is unreacted salicylic acid present.Try this with commercial aspirin, and you will find that even the commercial stuff has unreacted salicylic acid, so I am not sure this test is all that useful. Source(s):he complex is purple, so if adding iron (III) chloride turns the aspirin purple, there is unreacted salicylic acid present. Try this with commercial aspirin, and you will find that even the commercial stuff has unreacted salicylic acid, so I am not sure this test is all that useful. Source(s):