Numerical answer type, answer in g, tolerance 0.01.
Answer: 17.65 g
Let x mol of COX2 form. Then Kc=[COX2]/[CO]=x/(0.80−x) (the volume cancels because Δn=0). So x=0.80×0.65/1.65=0.3152 mol. Each mole of COX2 produces one mole of Fe, so mass =0.3152×56=17.648 g.