Twenty-four grams of magnesium metal reacts with sixteen grams of oxygen gas to form magnesium oxide. According to the law of conservation of mass, how much magnesium oxide will there be after the chemical change is complete?
24 g
30 g
40 g
16 g
The law of conservation of mass dictates that the total mass of reactants must be equal to the total mass of the products. Thus: mass(MgO) = mass(Mg) + mass(O) mass(MgO) = 24 + 16 mass(MgO) = 40 g
