Answer:
Mass ratio of magnesium = 2 : 1
Step-by-step explanation:
Let us write down the masses of element involve to form the compounds .
Compound A → 7.88 g of mg and 15.68 g of 02
Compound B → 2.12 g of mg and 6.91 g of 02
since we want to get the mass ratio of magnesium, we divide the mass of mg with the other element present (oxygen) . we want to make both compound in equal proportions.
Compound A → 7.88 / 15.68 = 0.5025510204 g of Mg /1 g of Oxygen
Compound B → 2.12 / 6.91 = 0.30680173661 g of Mg/ 1 g of Oxygen
Mass ratio of magnesium = compound A(Mg)/compound B(Mg)
Mass ratio of magnesium = 0.5025510204/0.30680173661
Mass ratio of magnesium = 1.63803186368 /1
Mass ratio of magnesium = 2 : 1