Answer:
50g of MgO
Explanation:
2Mg +O2 -----------> 2MgO
2moles of Mg needs 1mole of O2 for complete reaction ie
48g/mol of Mg --------- 32g/mol of O2
Xg of Mg --------- 30g of O2
X=45g of Mg
30g of O2 needs 45g of Mg, but only 30g of Mg is available, thus Mg is the limiting reagent.
2mole of Mg produces 2moles of MgO
ie 48g/mol of Mg ---------- 80g/mol of MgO
==> 30g of Mg -------------- Xg of MgO
X= 50g of MgO.