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

1 Answer
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.

In your case, you have

#color(blue)(2)"CO"_ ((g)) + "O"_ (2(g)) -> color(red)(2)"CO"_ (2(g))#

According to the balanced chemical equation that describes this reaction, the reaction consumes #color(blue)(2)# moles of carbon monoxide and #1# mole of oxygen gas and produces #color(red)(2)# moles of carbon dioxide.

So, carbon monoxide has a coefficient of #color(blue)(2)#. The same can be said about carbon dioxide, which has a coefficient of #color(red)(2)# as well.

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

#(color(blue)(2)color(white)(.)"moles CO")/(color(red)(2)color(white)(.)"moles CO"_2) = color(blue)(2)/color(red)(2) = 1/1#

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