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.
24 g
D.
30 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 a chemical reaction.

In this case, we have:

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

To find the total mass of the reactants: \[ \text{Total mass of reactants} = \text{Mass of magnesium} + \text{Mass of oxygen} \] \[ \text{Total mass of reactants} = 24 , \text{g} + 16 , \text{g} = 40 , \text{g} \]

Since all of the magnesium and oxygen react to form magnesium oxide, the mass of the magnesium oxide produced will also be 40 g.

Therefore, the correct answer is: A. 40 g