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?

Question

A.
40 g
B.
16 g
C.
30 g
D.
24 g

Answer 1

According to the law of conservation of mass, the total mass of the reactants must equal the total mass of the products.

In this case, you have:

• Mass of magnesium = 24 grams
• Mass of oxygen = 16 grams

Total mass of reactants = Mass of magnesium + Mass of oxygen = 24 g + 16 g = 40 g

Since the magnesium and oxygen react to form magnesium oxide, the mass of the magnesium oxide produced after the reaction will also be 40 grams.

Thus, the answer is:

A. 40 g