[student8607]

I'm told to write the equilibrium constant expression for Kc:
2NO(g)  N₂(g) + O₂(g)

Now since this is a decomposition, I believe I am to the the expression using Kc'.

Kc' = [O₂][N₂]/[NO]²

So how would I then write this in terms of Kc or do you think my Kc' expression is good enough?

[Astrokel]

What is decomposition got to do with Kc^'?

[student8607]

I thought that was when you use Kc'?

Or is it just when it says "reverse reaction?"

[Astrokel]

Only if it is reverse reaction then it is K_c^'.

[student8607]

But a decomposition is NOT a reverse reaction itself?

[Astrokel]

I'm told to write the equilibrium constant expression for Kc:
2NO(g)    N2(g) + O2(g)

Your question is what is the K_c expression for the above reaction. It has nothing to do with K_c^'

Remember Kc is just [products]^x/[reactants]^y and as long as you got your decomposition equation right, just follow it.

[student8607]

OK. Great. Thanks.