Given the equilibrium constant values:

N2 + 1/2O2 >>> N2O ; kc = 2.7 * 10^-18

N2O4>>>>2NO2 kc=4.6*10^-3

1/2N2 + O2>>>NO2 kc = 4.1 * 10^-9

What is a value of Kc for this reaction?

2N2O + 3O2 >>> 2N2O4

3 answers

i got 2.72 * 10^17, and got it wrong. i reversed the first by taking the reciprocal, and reversed the 2nd one, times 2 by the last one. added them, square rooted and then doubled. what did i do wrong
equation 1 x 2 and reverse. (1/K12)
equation 2 x 2 and reverse. (1/K22)
equation 3 x 4 as written. (K34 )

Kc = (1/K12)*(1/K22)*(K34) = ??

Check my work. Make sure the equations you have added together gets the equation you want at the end. I think this will do it. I've tried to write superscripts and subscripts but if I missed one of the "turn ons or turn offs" it will be messed up. I'll correct it if it appears to be too difficult to decipher.
High school teacher