# How are limiting reactants formed?

Feb 9, 2017

They are not so much $\text{formed}$; they simply exist as part of the starting conditions of the reaction.

#### Explanation:

We can represent the combustion of a $12 \cdot g$ mass of carbon in a furnace:

$C \left(s\right) + {O}_{2} \left(g\right) \rightarrow C {O}_{2} \left(g\right)$.

We don't need to measure the dioxygen gas that reacts with the carbon; in fact it would be inconvenient to measure it. Nevertheless, we know the molar quantity of carbon reacts, and we know that a $32.0 \cdot g$ mass of dioxygen gas reacts with it to give what mass of carbon dioxide?

Now, essential to a calculation of yield, and limiting reactant, is a stoichiometrically balanced equation. What does this mean in this context?