Question

At equilibrium, the concentrations in this system were found to be [N2]=[O2]=0.200 M and [NO]=0.500 M.
N2 + O2= 2NO

If more NO is added, bringing its concentration to 0.800 M, what will the final concentration of NO be after equilibrium is re-established?

Answer 1

Substitute the equilibrium concentrations into the Kc expression and solve for Kc. Use this below.

...........N2 + O2 ==> 2NO
I.......0.200..0.200....0.800
C.........+x...+x.......-2x
E.....0.200+x..0.200+x...0.800-2x

Substitute the E line into Kc expression along with the numberical value of Kc determined above and solve for x, then evaluate each of the values in the E line above. Post your work if you get stuck.