“We’re in the home stretches of classes:
For Gen Chem, the chapter on gases.
(Last subject to finish—
Its volume’s diminished
In pressure-increased circumstances.)”
The 2 December 2019 limerick builds on two key variables used in the specific context of gas chemistry to acknowledge a curricular constraint often seen at the end of a busy semester.
“We’re in the home stretches of classes: /
For Gen Chem, the chapter on gases.”
I’ve used a variety of textbooks in General Chemistry during my teaching career, but the break between fall semester coverage and spring semester coverage has consistently fallen between the discussion of gases and the discussion of condensed phases (solids and liquids). Thus the “home stretch” of General Chemistry 1– the final conceptual distance covered– is “the chapter on gases.”
“(Last subject to finish… /
Its volume’s diminished /
In pressure-increased circumstances.)”
One of the laws historically developed to describe gas chemistry was Boyle’s Law, which relates the pressure of a gaseous system to its volume; the law is named for Robert Boyle, who was a chemist and physicist who worked in the 17th century on many questions of scientific interest. Boyle’s Law states that as the pressure of a gas increases (assuming a constant amount at constant temperature), the volume decreases; as the pressure decreases (assuming a constant amount at constant temperature), the volume increases. The most widely used equation that expresses this relationship is p1V1 = p2V2, where p and V represent pressure and volume, respectively.
The last few lines of this limerick extend this relationship to the reality of a rapidly ending semester: when faced with the “pressure-increased circumstances” of the approaching final exam, instructors often must curtail coverage of a last chapter, causing its volume to diminish, in terms of the time devoted to it in class!
Chemphasis 