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

Answer 1

To determine the mass of magnesium oxide formed from the reaction of magnesium and oxygen, we can use the law of conservation of mass. According to this law, the mass of the reactants must equal the mass of the products.

In this case, we have:

• Mass of magnesium (Mg) = 24 grams
• Mass of oxygen (O₂) = 16 grams

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

Since magnesium oxide (MgO) is the only product formed from this reaction, the mass of magnesium oxide produced will also be 40 grams.

Therefore, the correct answer is: C. 40 g