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Concentration of nitrogen oxide in air

  • Thread starter Woopydalan
  • Start date
  • #1
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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.
 

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  • #2
NascentOxygen
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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.
 
  • #3
rude man
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Pose this in the chemistry section of PF.
 
  • #4
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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.
 

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