chemistry
posted by ellie on .
In the formation of smog, nitrogen and oxygen gas react to form nitrogen dioxide:
N2(g)+2O2(g)→2NO2(g)How many grams of NO2 will be produced when 2.1L of nitrogen at 840mmHg and 28∘C are completely reacted?
I know that you use the equation n=PV/RT to get the number of moles of nitrogen. What I am stuck on is getting the moles of NO2

Look at the coefficients in the balanced equation. With those you can convert mols of anything you HAVE in the equation to anything you WANT in the equation.
mols N2 x (2 mol NO2/1 mol N2) = mols N2 x 2/1 = ? mols NO2. 
When I solved the equation I got 3.1 grams of NO2. That isn't the correct answer. What did I do wrong?

I don't know. My crystal ball is cloudy tonight. :)
If you will post your work I will find the error. 
now you just need to multiply 3.1 by two= 6.2 is the answer... because there two mole of NO2 on one mole of N2