At high temperatures, iodine molecules can dissociate into iodine atoms. For the reaction I(g) 2 I(g) Kc = 1.27 10 at 900 C. A 20.5 g sample of I is placed in a 1.00 L vessel and heated to 900 C. What will be the molar concentration of iodine atoms, [I], in the vessel when the system comes to equilibrium?