Why teach the Gas Laws?

Mostly, it's an exercise in algebra and plugging into formulae. (if p=120 and t=600, what's the volume of 30g of water vapor?) Boooring!

Intuitively, it's just some obvious ideas (ceteris paribus):

• if you squeeze something, it gets smaller, like a spring
• if you heat it, it gets bigger
• if you have twice as much stuff, it takes up twice as much room.

Sure, it's mildly interesting to a non-scientist that:

• the exact quantitative relationships are simple
• they're the same for all substances

Even for scuba diving, for instance, the quantitative details aren't that important, just the fact that air is pretty compressible. The fact that the equation is fairly accurate is mostly of theoretical interest, which is to say not at all to ordinary persons. Unless the reasons for the law are explained, why should they care?

Of course, part of the problem is that the explanations are hard, but some of it is just that there's no time and we need something to test: the formulas make handy questions. Unfortunately, this encourages mindless plugging rather than understanding, and is a turnoff and certainly useless for the non-pre-professional student. Sometimes it's because the Gas Laws were ceded to the Chemists by the Treaty of Utrecht (or something in the past) and they don't really care about the subject.