How can you find a limiting reactant in a reaction?

1 Answer
Oct 6, 2016


A stoichiometrically balanced equation is an absolute prerequisite.


For many reactions, the reagent in deficiency is obvious. Consider combustion reactions; here, a limited amount of hydrocarbon is combusted in an unlimited quantity of dioxygen gas.

And thus for methane, we write:

#CH_4(g) + 2O_2(g) rarr CO_2(g) + 2H_2O(g)#

Here, of course, the reagent in deficiency is the hydrocarbon; the oxygen derives from the atmosphere. Under conditions of limited oxygen, and long chain hydrocarbon fuels, for instance in the internal combustion engine, #CO# and #C#, are observed as oxidation products, and these products represent incomplete combustion.

I presume you know how to convert mass to moles, and vice versa; if not give us a shout, and someone here will help you.