Help from an old textbook

Knowing just a little more is sometimes helpful.

Our consultant who tutors High School Chemistry (among other subjects) pulled out his undergraduate Physical Chemistry textbook a couple of weeks ago.  His intention was to try, once again, to understand Thermodynamics, something he never thought he’d quite managed.  Thermo, as a subject, has a reputation (deserved, in our opinion) for being difficult.  Its textbooks tend to make two utterly obvious claims, and derive from them something that is far from obvious and in fact looks rather implausible, with some sleight-of-hand involving partial derivatives that would not be out of place in a Las Vegas card game.

Well, he has made some progress, this time by paying careful attention to all the phrases and qualifications in the text.  (Details in Thermodynamics are important, especially those you miss.)  But at the same time he’s looked at other chapters in the book, recognizing the same subjects that some of his students are puzzling over.  Now, none of his students are working nearly at the level of this P-Chem text, which was meant for college juniors who are Chemistry majors.  However, the pieces of Chemistry they deal with are the same, for instance hybrid orbitals and the behavior of ideal gases.

We’ve mentioned before the peculiar difficulty of Chemistry as a High School subject.  At its base lies the heavily mathematical theory of Quantum Mechanics, which no High School student can be expected to master, and which indeed is very difficult to deploy in any bit of Chemistry that’s moderately complex.  So students are given simplifications, rules of thumb and exceptions, and some equations to use without any explanation of where they come from.  High School Physics is rather better, since the equations will look very much the same in college, though the mathematical sophistication increases there.

Our tutor found that he had forgotten many of the details of Chemistry at this level.  And he found that being reminded of them is helping him in his tutoring.  None of his students need to know the Schrödinger Equation, or even know of it.  But seeing it in action again helps him to explain the curious matter of hybrid orbitals.  And going through the chapter explaining, in mathematical detail, how gases depart from the Ideal Gas Laws helps him to clarify how those useful simplifications work.

It’s still true that he cannot really include the more advanced material in his tutoring; that would only confuse his students.  In that sense a teacher can, in fact, know too much to be effective.  But he’s found that being just a step or two ahead can be helpful.