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# Gas Laws

“The gas laws according to Boyle,
P, V, n, and T– traits
Of the phase that inflates–
In equations o’er which students toil.”

I will backtrack a day with this entry, as I inadvertently skipped posting my essay on the 8 April 2019 limerick!  This poem addresses another common introductory chemistry topic: the phases of matter. General Chemistry courses typically examine properties of solids, liquids, and gases. This poem references the development of some key equations via which the gas phase, specifically, is described.

“The gas laws according to Boyle,/
P, V, n, and T– traits/ Of the phase that inflates–”

As a student, I found the names associated with introductory chemistry to often be intriguingly distracting: the history of chemistry is mostly confined to sidebars in General Chemistry textbooks, but the stories are fascinating.

Several equations are named for scientists who worked on examining how physical properties of a gas sample are related; these are (Robert) Boyle’s Law, (Jacques) Charles’s Law, and (Amedeo) Avogadro’s Law.  The spark for this particular poem was a variation on the rules-of-cards phrase “according to Hoyle” with respect to Boyle’s name, specifically.

Boyle’s Law states that as the pressure on a gas sample increases, its volume decreases, if amount and temperature are held constant.  Charles’s Law states that as the temperature on a gas sample increases, its volume increases, if pressure and amount are held constant.  Avogadro’s Law states that as the amount of a gas increases, its volume increases, if pressure and temperature are held constant.

Pressure is represented with the variable P; volume, with V; amount, with n; and temperature, with T.  When linked together (“embroiled”), they comprehensively describe the properties of a gas, periphrastically described here as “the phase that inflates.”

“In equations o’er which students toil.”
The named laws listed above are typically combined into the Ideal Gas Law: pV = nRT, an equation that quantitatively (exactly) relates all four of a gas sample’s variables via the gas constant R.

The last line of the limerick is simply a rueful acknowledgement that, despite the elegance of any equations involved, truly learning chemistry– or any discipline– is difficult work!