What is the value of the equilibrium constant for the

Question

Use equilibrium concentrations to calculate K.

Some SO₃ is placed in a flask and heated to 1300 K. When equilibrium is reached, the flask is found to contain SO₃ (5.31×10^-3 M), SO₂ (1.85×10^-2 M), and O₂ (2.31×10^-2 M). What is the value of the equilibrium constant for the following at reaction at 1300 K?

2SO₃(g) <-----> 2SO₂(g) + O₂(g)    K = ________