# What is the mole ratio of CO(g) to CO_2(g) in the reaction 2CO(g) + O_2(g) -> 2CO_2(g)?

Mar 12, 2017

$1 : 1$

#### Explanation:

The mole ratio that exists between two chemical species that take part in a chemical reaction is simply the ratio that exists between the stoichiometric coefficients added in front of said species.

$\textcolor{b l u e}{2} {\text{CO"_ ((g)) + "O"_ (2(g)) -> color(red)(2)"CO}}_{2 \left(g\right)}$

According to the balanced chemical equation that describes this reaction, the reaction consumes $\textcolor{b l u e}{2}$ moles of carbon monoxide and $1$ mole of oxygen gas and produces $\textcolor{red}{2}$ moles of carbon dioxide.

So, carbon monoxide has a coefficient of $\textcolor{b l u e}{2}$. The same can be said about carbon dioxide, which has a coefficient of $\textcolor{red}{2}$ as well.

This means that the mole ratio that exists between carbon monoxide and carbon dioxide will be

$\left(\textcolor{b l u e}{2} \textcolor{w h i t e}{.} {\text{moles CO")/(color(red)(2)color(white)(.)"moles CO}}_{2}\right) = \frac{\textcolor{b l u e}{2}}{\textcolor{red}{2}} = \frac{1}{1}$

Because the two coefficients are equal, we say that the two compounds have a $1 : 1$ mole ratio.