Calculate the number of moles of `O_2` required to produce 240 g of Mgo by burning magnesium metal

Explanation

`2Mg+underset(1"mole")(O_2)tounderset(2(.24+16)=8002MgO)(2MgO)`Number of moles of `O_2` required to produce 80 g MgO = 1 mole `therefore` Number of moles `O_2` required to produce 240g MgO = `1/80xx240=3` moles