In the Lord of The Rings book, Tolkien imagines a very ancient creature (an Ent, or tree-man, called “Treebeard”) who happens to cross the way of two little, and very anxious, hobbits. The wise Ent’s frequent advice to the hobbits is “do not be hasty!”.
This is a good advice for chemists to hear, too… when in University, we usually look for the perfect reaction’s outcome, 99% conversion, 99% yield, 99% enantiomeric excess. But, as soon as we leave this fairy kingdom, industries demand other objectives from us: 99% money, 0% waste, 0% time spent. How very different!
Maybe I should mention a big exception: biochemists are very seldom unaware of the “elapsed time” factor, because living systems (both single cells and complex organisms) need a huge amount of different reactions to preserve their life. Therefore it is crucial for them to finely tune all reactions (by developing the right enzymes and control mechanisms) which take place simultaneously.
The issue is very important, because sometimes we think too much about chemical equilibrium, forgetting that many systems (living organisms have already been mentioned, for example) do not reach equilibrium at all! A simple yet funny example is the transformation of diamond into graphite. I usually teach thermodynamics before kinetics, and as soon as students understand enthalpy, I tell my male students why they shouldn’t buy a diamond for their girlfriends: of course, because enthalpy says it will eventually become a useless piece of graphite.
This obviously does not sit well with many female students, but they do get vendetta: kinetics later explains why diamonds are eternally (“for a very long time” seems to me far less poetic) a girl’s best friends.
All reactions need a certain amount of time to reach equilibrium, and kinetics help us understand the key factors which guide the process (more about this in my next post).
In the Physical Chemistry textbook, Chapter 9 describes the basics of chemical kinetics, as well as some powerful techniques to study the speed of reaction in different systems.
On a slightly different note, I have to admit that I PARTICULARLY appreciated Henry Eyring’s biography at the end of the Chapter, for a number of reasons: first of all, he has been an inspiring guide for all theoretical chemists like me, who believe good chemistry can be obtained even with paper and pen (and computer simulations 😀 ). Secondly, he has worked with K. J. Laidler, who is one of the authors of the book we are speaking of; last, but not least, he was a very religious man, confirming that faith and science have nothing to fear from each other but can coexist.
Some of you, my readers, may inquire the reason for focusing on a biography? Well, DO NOT BE HASTY. Science does not exist without scientists.
One can forget about the man/woman without forsaking the theory they advanced – that is science’s strength. However, it means forgetting that every page of knowledge passed down to us comes from the sweat and the mind of someone, whom we can thank in two ways: remembering and learning from him/her.