102L Open-book, group take-home quiz (in lieu of an in-class quiz!):

This pertains to the 11th quiz, which you may wish to look at for further details.

4. After your "esterification" reaction joined an acetate onto your alcohol, your reaction mix contained a lot of acetic acid (essence of vinegar) in it.

  1. (5 pts) What did you do to separate it away from your desired product?



  2. (10 pts) Why did that procedure work?




8. (15 pts) Another way of making an ester is by boiling the alcohol together with acetic acid for a long time. Suppose that if the Keq = 2, is most of the alcohol converted to ester? (Hint: write out the reaction so you don't miss anything!)



    This section deals with more thoughtful questions. Perhaps 80% of the way getting to the answer is what you have had in class, but then there is another 20% of your own delving into new territory. Science is, you know, the art of exploration and discovery - not the memorization of past-established facts.

  1. (20 pts) Let's see how really smart you are! Suppose you add equal molar amounts of anhydrous iso-amylol, anhydrous acetic acid and CaCl2 drying agent to a flask and begin heating it. How does the CaCl2 cause a greater amount of banana essence to form? (Hint: if you pour some dry CaCl2 onto the tabletop on a humid day, soon there is a small puddle on the table.)



  2. (10 pts) Suppose that you invented a type of sand that was covered with positive charges. (Hence, each granule was a poly-cation.) Your idea was to make your post-esterification mix basic, and then add these granules to the mix in hopes that all the acetate anions would stick to the granules. You could then use filter paper to strain out the acetate coated granules and thus quickly rid the mix of unwanted acetate. Would the banana essence (your ester), and/or the iso-amylol stick to the granules?



  3. (25 pts) Pretend that you are a pharmacologist - inventor of medicines and not a pharmacist (dispenser of meds). One of the national needs is a medicine that will lower "bad" cholesterol, and raise the "good" in the human body. Interestingly, it was found that by far the best agent - and very cheap at that! - for doing this was the vitamin called niacin. However the necessary dosage was nearly 5-times the daily requirement, and at that dosage most people suffer a severe, but short-term side-effect, which is an intense facial hot-flash as if boiling water were dumped onto their heads, and also their vision narrows and ears ring. This lasts for about 10 excrutiating minutes - happily, all this happens with little subsequent deleterious effect. But here you are: you have read the previous 11 questions. Is there anything in those questions that might prompt you to devise a way to ameliorate the side-effects of the full niacin 5X-dose? (Write your answer on the other side of this page.)