Answer:
The answer to your question is 30 moles of COâ‚‚
Explanation:
           CS₂  +  3O₂  ⇒  CO₂  +  2SO₂
We know that 3 moles of oxygen produce 1 mol of carbon dioxide, then use proportions to find the amount of COâ‚‚ in the conditions given.
           3 moles of O₂ ---------------  1 mol of CO₂
          90 moles of O₂ -------------  x
           x = ( 90 x 1) / 3
           x = 90 / 3
           x = 30 moles of COâ‚‚               Â