Ethene (C2H4) reacts with halogens (X2) by the following reaction:
C2H4(g) + X2 == C2H4X2(g)
The following figures represent the concentrations at equilibrium at the same temperature when X2 is Cl2 (green), Br2 (brown), and I2 (purple). List the equilibria from smallest to largest equilibrium constant. [Section 15.3]