My inorganic chemistry lab manual has all sorts of policies, procedures, experimental instructions, and examples of what to do in the lab and for the writeups. My manual is quite specific in how I want lab reports to appear, and what I want in them. For example, I want a reaction scheme, a reagent table, an evaluation of possible characterization methods (with limited time, which methods are the best to do first?), a detailed experimental section and a complete, open-ended, discussion that analyzes the data from their synthetic reaction. But what about all the stuff that I don’t want to see? I needed a list of stuff NOT to include.
For that reason, I have a collection of “pet peeves” that I share with my students on the first day of class every spring. The list started with a forum post after an especially bad round of grading, apparently, and since that time I have included the following list as the infamous “Appendix 9.” As I've included a few hyperlinks to provide context, I might just have to include a link in my lab manual to this blog post in future years.
This list may offer more information about my psyche and sense of humor than any actual relevant information on writing tips, but my students get a kick out of it. And there is usually one joker who insists on using the word “moiety” in every writeup, just to spite me.
Scientific Writing Tips from Professor Johnson
In addition to the information in the prior appendices on what to include in your lab writeups, I thought I would also include a list of my favorite writing pet peeves. Don't make these mistakes, they make me see red. That's never good.
1) Reacting things. Molecules react with each other. You don't react molecules with each other. React is an intransitive verb. You can mix things, you can treat one compound with another, you can allow two chemicals to react, but you can't react them.
2) Refluxing things. Reflux is a noun. You heat something at reflux.
3) Creating. You can synthesize things. You can also prepare, make, or bring them about, but you can't create them. I don't see major religions being formed around you. Sure, it’s pedantic. Sure, it’s petty. But these are my pet peeves. If you don't like them, go become a professor and teach your own class....
4) You don't take an NMR. You use NMR to acquire an NMR spectrum. You characterize something by NMR spectroscopy, using an NMR spectrometer.
5) No discussion in the experimental. No interpretation. Just the recipe and the facts. The discussion is for interpretation/analysis of the facts.
6) First person pronouns. Most science should be described in a distant protracted way. Don't use personal pronouns. You can almost always strengthen a sentence. "We studied the properties of this compound" turns into "The properties of the compound were examined" or, using an active verb, "the NMR spectrum of the compound revealed these properties."
7) Yields to 4 sig figs. Come on people! If you were to repeat the experiment exactly the same, would you get the same mass to 4 sig figs? Let's be realistic and truncate to the ones place.
8) "Passive voice" does NOT mean "omit the subject from every sentence"? Passive voice makes you sound like a scientist. Leaving out the subject makes you sound like Thag the Caveperson.
9) Don't change tense half-way through an experimental. If you start in the past tense, stay that way throughout. The only confusion is when you talk about properties of the compound. Even if you "made" it last week, it "is" yellow, though it "was observed to be yellow."
10) Drawing structures. Did you know that Chemdraw can draw angles properly? In fact, it is the default, unless you turn it off, or do it incorrectly. Methyl groups coming off of aromatic rings at angles other than 120° drive me bonkers. My brain actually hurts. Learn how to use the program!
11) Moiety. All it tells me is that you know a fancy word for "thing." When I see the word moiety, I read the word "thing." And using "thing" as a noun in a junior level chemistry class just doesn't get you very far. There is a correct use of the word moiety, but I have not ever seen a student use the word correctly. Addendum 2017: apparently enough people have abused this term that now it is considered acceptable by IUPAC. However, to me, it still means "thing."
12) Reaction mixtures can be filtered. You can collect the filtrate. But your solution can never be filtrated.
13) Blindly accepting spell check "FeCl3·6H2O (0.8281 g, 0.0031 mol) was ground into a fine powder with a ceramic mortal and pestle." This student’s writing will be forever immortalized here.
14) A compound can be purified by sublimation. You might think that you would be able to "sublime" something, but you can’t; see rule 1. However, you can never "sublimate" something. Nor do you use a "sublimator" (although Google will tell you otherwise). "Sublimate" means to repress certain feelings in a Freudian sense.
15) "The purpose of this lab...," "In Part A of this lab..., " "Our major source of error was..." Seriously. You HAVE to be able to write a lab report without using these phrases. It’s a level of sophistication that I expect.
16) Tautologies. "The reaction is slow because of the small rate constant, " "HCl is more acidic than HOAc because the pH is lower, " or "Co2+ is more labile than Co3+ because the ligands come on and off more easily." Don't restate a factual statement using different words as your ONLY explanation.
In addition to the writeup pet peeves above, I have a shorter list of:
Lab experimentation pet peeves:
1) Putting a sep funnel in the oven. By definition, (by DEFINITION!) what is the NEXT thing you are going to put in the sep funnel?
2) Using air nozzles to "dry" your glassware. It is likely that you don't actually need dry glassware, and if you did, the huge amounts of water left on the glassware will kill any water sensitive reagent you were about to add anyway. Plus, did you filter out the dust and pump oil vapors from the "clean" air coming out of the nozzle?
Note added in review: The reviewer gets slightly annoyed by mixing single spacing and double spacing after periods. Hopefully all of these have been corrected.