Posted by bkue on .
A 2 liter container holds 2.2 mol of NH3 gas, which starts to decompose according to the following reaction.
At equilibrium there are .6 mol of H2.
Determine the concentrations of NH3, H2, and N2 at equilibrium.
2NH3> 3H2+N2
^ all gas

chem, find concentrations 
DrBob222,
.........2NH3 ==> N2 + 3H2
I.........2.2.....0......0
C.........2x......x.....3x
E.......2.22x.....x......3x
The problem tells us that there is 0.6 mol H2 at equilibrium. So 3x = 0.6 mol which means x = 0.2 mol. (Note that I did NOT change H2. It still is 0.6 mol. For proof of that 3x = 3*0.2 = 0.6. I write this only because I helped a student last week with this and she thought I had changed H2 but I didn't.)
That gives you N2 (x) and NH3 = 2.22x.
Then divide mols each by 2 L to obtain concn of each.