Which of the following is the correctly balanced chemical equation for the combustion of magnesium?

• A. Mg + O_2 → MgO_2
• B. 2 Mg + O_2 → Mg_2O_2
• C. 2 Mg + O_2 → 2 MgO
• D. Mg + O_2 → MgO

Answer: (C)

Verified step by step guidance

1. Identify the reactants and products in the combustion reaction of magnesium. Magnesium (Mg) reacts with oxygen (O_2) to form magnesium oxide (MgO).
2. Write the unbalanced chemical equation: \(\mathrm{Mg} + \mathrm{O}_2 \rightarrow \mathrm{MgO}\).
3. Balance the magnesium atoms by ensuring the same number of Mg atoms on both sides. Since Mg appears as a single atom on the left and in MgO on the right, start by placing a coefficient of 2 in front of Mg on the left: \$2 \mathrm{Mg} + \mathrm{O}_2 \rightarrow 2 \mathrm{MgO}$.
4. Balance the oxygen atoms. On the left, oxygen is in O_2 molecules (2 atoms), and on the right, each MgO contains 1 oxygen atom. With 2 MgO units, there are 2 oxygen atoms on the right, which matches the 2 oxygen atoms in O_2 on the left.
5. Confirm that the equation is balanced with 2 Mg atoms and 2 oxygen atoms on both sides, resulting in the balanced equation: \$2 \mathrm{Mg} + \mathrm{O}_2 \rightarrow 2 \mathrm{MgO}$.