# What is a limiting reactant problem?

May 14, 2018

Well, usually all combustion reactions are such...

#### Explanation:

A $16 \cdot g$ mass of methane is combusted in air....

$C {H}_{4} \left(g\right) + 2 {O}_{2} \left(g\right) \rightarrow C {O}_{2} \left(g\right) + 2 {H}_{2} O \left(l\right) + \Delta$

CLEARLY, methane, the hydrocarbon, is in stoichiometric deficiency, and dioxygen is the reagent in EXCESS... So how much carbon dioxide is produced from the given reaction? Take that atmosphere...!

Note that sometimes, especially for long-chain hydrocarbons, such as diesels, INCOMPLETE combustion can occur to give carbon and carbon monoxide as the products of incomplete combustion. We could represent this by saying that SOME $C O$ and $C$ result from a diesel combustion reaction, i.e.

${C}_{10} {H}_{20} + \frac{27}{2} {O}_{2} \rightarrow 8 C {O}_{2} \left(g\right) + C O \left(g\right) + C \left(s\right) + 10 {H}_{2} O$

Is this balanced? Clearly, we would have to interrogate the combustion products in order to represent the reaction....