Phosgene is a potent chemical warfare agent that is now outlawed by international agreement. it decomposes by the reaction: cocl2 (g) ⇋ co (g) + cl2 (g) kc = 7.5 x 10-5 (at 362°c) calculate the concentration of co when 7.73 mol of phosgene decomposes and reaches equilibrium in a 10.0 liter flask. multiply your answer by 103 and enter that number to 2 decimal places. hint: look at sample problem 17.9 in the 8th ed of silberberg. write a kc expression. calculate the initial concentration of phosgene. do an ice chart. find the concentration of co.