Today I made aspirin. Next up… meth! I kid. At chemistry lab tonight, we synthesized aspirin–it was pretty cool.
I find it amazing how creative and yet utterly logical that chemists have to be to come up with a procedure for synthesizing a specific chemical. In order to arrive at a destination (aspirin in this case), the chemist has to follow a very specific procedure. Well, not necessarily. There are multiple procedures and multiple ways in which each step can be accomplished, and that’s where the creativity comes in.
Let’s say you want to make C9H8O4 (i.e. aspirin). From the formula, we know that each unit of aspirin contains 9 carbon atoms, 8 hydrogen atoms, and 4 oxygen atoms. The problem is, we can’t just take 9 moles of carbon, 8 moles of hydrogen, and 4 moles of oxygen, put it all in a bag, shake it for a few minutes and open the bag to find aspirin. Oh, no! We’d probably be left with a pile of carbon at the bottom, oxygen gas in the middle, and a bunch of highly flammable hydrogen awaiting us at the top of the bag.
The puzzle is, how to we utilize the different properties of different chemicals to create a specific chemical that we don’t yet have? Well, in our case, we mixed salicylic acid (the stuff you put on warts) and acetic anhydride (it’s basically dried vinegar) together and added a few drops of phosphoric acid to speed things up. Then we applied heat, which caused the stuff to magically react to form something that was not in the test tube to begin with. Who would’ve thought? But now our aspirin is contaminated by an excess of acetic anhydride. How can we get rid of it? I know, let’s add water! (I’m trying to think like the chemist who invented the procedure.) That will turn the acetic anhydride into vinegar which can be filtered out of the aspirin crystals. That’s basically the process we used to synthesize crude aspirin. If you’re interested, you can find the full procedure here.
Our class’ synthesis of aspirin was simple by chemistry standards, but it gave me a peek into the mind of a chemist. A chemist is much like a chef. A chef has an extensive knowledge of the properties of different foods and spices. He or she thinks logically–following multi-step procedures in a specific order to create a product worthy of awe. The chef is precise–too much or too little of any spice will ruin the product. The true chef is also creative–the true chef experiments and designs new procedures that yield amazing new products. The chemist, I’ve come to see, is much like the chef. There is careful precision, there is a lot of logical planning and procedure-building, but there’s also creativity and experimentation. If I wasn’t so set on making Star Trek a reality, I would be quite happy being a chemist.