“The arrow’s most classic citation
Provides chem reaction’s narration:
Reactants yield products;
Denoting said progress,
The “verb” in the balanced equation.”
The 17 April 2023 limerick discussed the most traditional use of an arrow within a chemical reaction’s setting: showing the reaction progress moving forward from reactants to products.
“The arrow’s most classic citation /
Provides chem reaction’s narration…”
If a student has encountered previous chemistry coursework, the first arrow of interest is likely familiar; it is a relatively “classic citation,” as such discussions go.
When a reaction is written on a sheet of paper, reactants are written on the left-hand side, while products are written on the right-hand side. In between them is a single-headed arrow pointing from left to right.
This arrow thus “narrates” the process by showing that the reactants on the left will form the products on the right, over the course of the chemical reaction.
“Reactants yield products; /
Denoting said progress, /
The ‘verb’ in the balanced equation.”
These last three lines are a rhymed restatement of the last point from the previous section. This arrow in the reaction is what conveys the actual progress of the chemical step underway, becoming the “verb,” as one translates a chemical reaction’s notations to words.
Below is a reaction I’ve written about previously in this space, carbonatation (or carbonation), in which a fresco surface reacts with carbon dioxide in the air to provide a work of art notable for its longevity.
Ca(OH)2 (aq) + CO2 (g) → CaCO3 (s) + H2O (l)
This reaction can be translated to words: aqueous calcium hydroxide and gaseous carbon dioxide react to form solid calcium carbonate and liquid water.
The chemical formulas each correspond to a precise compound name; the letters in parentheses, to a description of each compound’s phase; the arrow corresponds to the phrase “react to form.”
Future poems on this theme will examine arrows that represent more complicated phenomena, but this first example is relatively simple.
Chemphasis 