Oh, chemistry is not as clear-cut as we’d like her be,
And here she shares a field to wield with physics, we perceive.
Although the math’s elusiveness will sometimes us deceive,
“We love [her still] for what she is and what she is to be.”
(And that’s an altered quotation from “America for Me.”)
Now, first and foremost energy’s the most important name,
It’s never lost in any spot nor created in the same.
But energy, or letter E, has signs that change as well,
It’s positive when going in and negative for out!
Now, add the heat and work all up, you get the delta E;
The sign delta just shows a change all so conveniently.
Now take the delta of PV and add it to the chain,
It now becomes the delta of enthalpy, letter H!
But what you’ve done essentially is eliminating work,
And delta H and heat alone are then left to concur.
You’ve ever wondered in your ponders how to ever tell
Reactions spewing molten rock from those whose temp’tures fall?
Well, here’s the key of th’ mystery: it’s standard enthalpy!
Subtract th’ reactants’ from th’ products’; th’ heat of reaction (is) left.
If it is big and negative, then run away and hide!
Who knows if the reaction’s heat will blast its beaker’s side? [no curse word intended for blast]
But if it’s big and positive, then grab a pair of gloves;
Watch (for) frostbites since th’ reaction takes a lot of heat t’ go out!
Academic Rhymes 