How To Determine If There Was A Reaction In A Chemical Equation

Chemical equations represent the language of chemistry. When a chemist writes "A + B –> C," he's expressing a relationship between the reactants of the equation, A and B, and the product of the equation, C. This relationship is an equilibrium, although the equilibrium is often one-sided in favor of either the reactants or the products. Not every chemical equation a chemist writes represents a productive reaction, however. Learn the conventions of chemical equations to determine whether the equation you are analyzing represents a reaction.

Step 1

Write the chemical equation you want to analyze; for example, the reaction of a strong acid (HCl; hydrochloric acid) and a strong base (NaOH; sodium hydroxide): "HCl(aq) + NaOH(aq) –> NaCl(aq) + H2O(l)." Note that the arrow in the equation means "yields."

Step 2

Identify any chemical terms in the equation to the right of the arrow. For example, you identify NaCl (sodium chloride, or common table salt) and H2O (water).

Step 3

Note that when there are chemical terms to the right of the arrow in a chemical equation, there is a reaction.

Step 4

Write another chemical equation you want to analyze; for example, the combination of sodium chloride (NaCl) and calcium nitrate (Ca[NO3]2): "NaCl(aq) + Ca(NO3)2(aq) –> NR." Remember that "NR" means "no reaction."

Step 5

Note that there are no chemical terms to the right of the arrow. No reaction takes place in the chemical equation you have written.