Question

Hey again Matt! I have another question if you can help me! How many grams of magnesium oxide can be produced when 97.2 g Mg react with 88.5 g O2? The unbalanced equation is: Mg + O2 → MgO I already balanced the equation to 2Mg + O2 → 2MgO

Answer 1

2Mg + O₂ = 2MgO

n(Mg)=m(Mg)/M(Mg)
n(Mg)=97.2g/24.3g/mol=4 mol

n(O₂)=m(O₂)/M(O₂)
n(O₂)=88.5 g/32.0 g/mol=2.77 mol

Mg:O₂  2:1   4:2
4:2.77
the oxygen is in excess
the calculation for the magnesium

n(MgO)=n(Mg)

m(MgO)=n(Mg)*M(MgO)

m(MgO)=4 mol * 40.3 g/mol = 161.2 g

161.2 grams of magnesium oxide can be produced