A researcher put 10.0 moles of N2O into a 2-L container at some temperature where it decomposes according to the following: N2O = 2N2+ O2. At equilibrium 2.20 moles of N2O remain. Calculate the Kc for the reaction.

How am I supposed to fill in the ICE chart if Kc isn't given for me to plug into the constant equation? Please help, I can't find the the equilibrium for 2N2 + O2.

1 answer

Kc is what they want you to calculate.
Initial (N2O) = 10 mols/2L = 5.0 M
Eq (NO2) = 2.1/2 = 1.1 M.

Your equation isn't balanced.

.......2N2O ==> 2N2 + O2
I......5.0M......0.....0
C......-2x......+2x....x
E......1.10M.....2x....x

So 2x = 5.0-1.1 = 3.9
Solve for x, fill in the ICE chart, substitute into the Kc expression and solve for Kc. Just some reasoning to get the ICE chart filled in. Post your work if you have more trouble.