Concentration of nitrogen oxide in air

[member 392791]

Homework Statement

The relative compositions of the pollutants NO and NO2 in air are governed by the reaction

NO + 1/2 O2 ⇔NO2

For air containing 21-mol% O2 at 25C and 1.0133 bar, what is the concentration of NO in parts per million if the total concentration of both nitrogen oxides is 5 ppm? Note ppm is taken on a molar basis for gases.

Homework Equations

The Attempt at a Solution

For this problem I am not sure how to go about it. I am not 100% sure if ppm means moles/total moles. Also, I am not able to find out the concentration of NO2 at equilibrium, which is why I haven't been able to get the concentration of NO.

 

[NascentOxygen]

My chem study is too long ago to be able to help you. But I think I'd be looking for some sort of equilibrium constant at that temp & pressure, to be able to relate the proportion of moles of NO2 to NO. Do you have that?

Have you tried a google search? Often you can find a worked example on which you can base your approach.

 

[rude man]

Pose this in the chemistry section of PF.

 

[Chestermiller]

Homework Statement

The relative compositions of the pollutants NO and NO2 in air are governed by the reaction

NO + 1/2 O2 ⇔NO2

For air containing 21-mol% O2 at 25C and 1.0133 bar, what is the concentration of NO in parts per million if the total concentration of both nitrogen oxides is 5 ppm? Note ppm is taken on a molar basis for gases.

Homework Equations

.

The Attempt at a Solution

For this problem I am not sure how to go about it. I am not 100% sure if ppm means moles/total moles. Also, I am not able to find out the concentration of NO2 at equilibrium, which is why I haven't been able to get the concentration of NO.

In this context, ppm means mole fraction times 1 million.