Posted by aijaz on .
at 727 degree centigrade,K=3.8*10^5 for the dissociation of I2 into iodine atoms: I2<>2I. if the original concentration of molecular iodine is 0.20 mol/L calculate the concentration of atomic iodine at equilibrium. check to see if the hundred rule is applicable

chemistry 
DrBob222,
...........I2==> 2I
I........0.20....0
C.........x....2x
E......0.20x....2x
K = (I)^2/(I2)
Substitute from the ICE chart and solve or x. I don't know what the hundred rule is but the answer is within 5% so you can make the approximation that 0.20x = 0.20.