Magnesium oxide (MgO) forms when the metal burns in air. (a) If 1-25 9 of MgO contains 0.754 g of Mg, what is the mass ratio of magnesium to oxide? (b) How many grams of Mg are in 534 g of MgO?

a)

1.25 g MgO contains. 754 g of Mg. Rest will be O

so oxide = 1.25 -.754 = 0.496 g

ratio of magnesium to oxide =.754/.496 = 1.52

b) 1.25 g of MgO contains. 754 g of Mg

534 g of MgO contains. 754 x 534 / 1.25 g = 322.11 g