For the equilbrium system SnO2(s) + 2 H2(g) equilibrium reaction arrow Sn(s) + 2 H2O(g) at 500 °C, [H2O] = [H2] = 0.10 M.

Enough H2 is added to raise its concentration temporarily to 0.20 M. When equilibrium is reestablished, what are the concentrations of H2O and H2?