Question

Consider the following reaction in the solvent CCl4 in a 1-L flask:
2IBr(g)<->Br2(g)+I2(g)
What is the equilibrium moles of IBr, Br2 and I2 are 0.2, 0.1 and 0.1, calculate the equilibrium constant Kc.

Answer 1

I assume you mean the equilibrium mols are as given and you want to know Kc.
(IBr) = 0.2/1 L - 0.2M
(Br2) = 0.1/1) = 0.1M
(I2) = 0.1/1) = 0.1M
Then Kc = (Br2)*(I2)/(IBr)^2
Substitute and solve for Kc.