1. At room temperature benzoic acid dissolves in the less polar solvent, ether, but not very much in the more polar solvent, water. However, the deprotonated species, the benzoate ion, dissolves in water but not ether. What does this tell you about the relative polarity of benzoic acid compared to the benzoate ion? Justify your answer.
2. The solubility of caffeine in water in 2.2mg/mL at 25C and 670 mg/mL at 100C. How mL of boiling water would it take to dissolve 23g of caffeine? If the solution was cooled to 25C, how many grams of caffeine would recrystallize out? Show your detailed work.
3. Calculate the % yield for the following reaction, based on the results regarding the synthesis of 2-iodooctane from 2-chlorooctane. Show all calculations.
2-chlorooctane + NaI =(supposed to be an arrow here) 2-Iodooctane
100mg (excess) 75 mg
4. (R)-2-Bromobutane is reacted with a solution of NaI: however, the label is blurry and it is unclear what solvent the NaBr is dissolved in. Upon isolation of the product it appears to be optically inactive. Explain what must have happened mechanistically. If your goal is to synthesize (S)-2-iodobutane, how might you modify the experiment to ensure that you do so in your next attempt?
5. A shelf containing several chemicals (Salicylic acid, 4-(4-Hydroxyphenyl)butan-2-one {a.k.a. Raspberry Ketone} and 4-methylaniline) fell and the vials shattered. The white powders are hopelessly mixed in a dustpan. You are promised a big fat raise if you can construct a flowchart that a less qualified chemist will follow to separate the three compounds. You must label what extraction steps are to be taken at each point of the separation and how to isolate each compound again as a solid. To ensure that you get the raise, you will also need to suggest a simple chemical test (not spectral) to test the functional groups present in each compound.