[bethanypamela]

Hello all, I'm totally new here. I'm completely stuck with how to calculate K_c, my tutor at college has given us this question:

For the equilibrium N₂O₄(g) ⇌ 2NO₂(g)

Equilibrium concentrations are:
NO₂(g) = 1.60 mol dm^-3
N₂O₄(g) = 0.200 mol dm^-3

Calculate K_c

Now, I'm not asking to cheat, this is the first time I've been truly stumped. It's probably something simple I'm missing... I'm completely clueless. Any help would be incredibly appreciated!
Thanks for reading

[Borek]

What is the formula for the Kc for this system?

[bethanypamela]

Thanks for getting back to me!
We weren't given any other information but after attempting to understand, I think it is

K_c = (C)(D) / (A)(B) ²

But honestly this is admittedly why I am confused, if that isn't the required formula then I am lost.

[bethanypamela]

Supposed to be square brackets there. Sorry.

[Corribus]

Not quite.

http://en.wikipedia.org/wiki/Equilibrium_constant

Keep in mind you only have 1 reactant and 1 product in your case, so you will only have one term in your numerator and one in your denominator.

[AlphaScent]

This may be easier

http://www.chem.purdue.edu/gchelp/howtosolveit/Equilibrium/Calculating_Equilibrium_Constants.htm

[bethanypamela]

Thank you so much for your help - I see now that I was over thinking it!