How many moles of NO₂ would be produced from 4.5 mol of O₂ in the reaction below assuming the reaction has a 57.0% yield?

Question

2 NO (g) + O₂ (g) → 2 NO₂ (g)

Answer 1

Let us use dimensional analysis first to solve how many moles of NO₂ would be created at 100%.

4.5 mol O₂ x (2 mol NO₂/ 1 mol O₂) = 9 mol NO₂

If only 57% was made:

9 mol NO₂ x 0.57 = 5.13 moles NO₂.