Consider the equilibrium A <----> B. The equilibrium constant is Kc = 0.909, and the initial concentrations are [A]0 = 0.17 mol/L and [B]0 = 0 mol/L. Compute [A] after equilibrium has been reached.
(Using correct significant figures.)
It shows how to calculate the equilibrium concentration. The solution is detailed and was rated '5/5' by the student who originally posted the question.