Easy!
All you have to do is look at the formula.
Lead Sulfide is PbS
Lead Oxide is PbO
Sulfur Dioxide is SO₂
Oxygen is O₂
You would need to balance out the equation, so it would be PbS + O₂ --> PbO + SO₂.
We can balance this out with the following. 2PbS + 2O₂ --> 2PbO + SO₂.
So 0.500 moles of oxygen would be the same conversion rate for PbO so it would also be 0.500 moles of lead oxide (PbO)
