(Solved): Procedure B: Bicarbonate Test for an Acid To see if you did get some kind of acid as a product, you ...

Procedure B: Bicarbonate Test for an Acid To see if you did get some kind of acid as a product, you'll do some tests on the crude, wet product. Place a small amount of the crude product in a test tube, add to it a few millititers of sodium bicarbonate solution, and mix. Bicarbonate (hydrogen carbonate) will act as a base if there is acid present, forming carbon dioxide gas. Observation B1: What do you see when you do this test? Question B1: The reaction has three acids in it; one reactant and both products are acids. Does this test confirm that your crude product is aspirin? Procedure C: Iron (III) Test for SalicylichAcid If the synthesis has been unsuccessful, there will be a lot of unreacted salicylic acid present in the crude product. Also, when pure aspirin decomposes over time, it reverts to salicylic acid and acetic acid. Old bottles of aspirin may smell like acetic acid if this has happened. Salicylic acid is irritating to the stomach so it's important to see if the aspirin contains significant concentrations of this impurity. A quick USP 'spot test' for the presence of salicylic acid is to add a solution of iron (III) cation to the aspirin. If there is salicylic acid present, a dark purple color will form as the phenolic $?\mathrm{OH}$ group of salicylic acid reacts with the iron (III). Question C1: Why wouldn't you expect to see the purple color upon testing pure aspirin? Set up a rack with three test tubes. Into the first, place a small amount of your crude, wet aspirin product. Into the second, place a small amount of crushed, commercial aspirin. Into the third, place a small amount of pure salicylic acid as a control. To each tube, add $5\mathrm{mL}$ of iron (III) chloride (ferric chloride) solution and shake. Let settle for 1 min, then observe the solution layer. Observation C1: Results for your crude product: Observation C2: Results for commercial aspirin: Observation C3: Results for pure salicylic acid: Question C2: Interpret each of the three test results. What can you conclude?