Consider the following reaction:
cus(s) + o2(g) ⇌ cu(s) + so2(g)
a reaction mixture initially contains 2.9 m o2.

determine the equilibrium concentration of o2 if kc for the reaction at this temperature is 1.5.

1.2 M

Explanation:

Let's consider the following reversible reaction.

CuS(s) + O₂(g) ⇌ Cu(s) + SO₂(g)

To find the equilibrium concentration of O₂ we will use an ICE Chart. We will only consider gases and aqueous species since the activity of solids and liquids is 1.

    CuS(s) + O₂(g) ⇌ Cu(s) + SO₂(g)

I                    2.9                      0

C                    -x                      +x

E                  2.9-x                     x

The equilibrium constant (Kc) is:

The concentration of O₂ at equilibrium is:

[O₂] = 2.9 -x = 2.9 - 1.7 = 1.2 M

i'm pretty sure its b i might be wrong though!