Which of the following is the correctly balanced chemical equation for the reaction between elemental phosphorus, P_4(s), and oxygen gas, O_2(g), to form tetraphosphorus decoxide, P_4O_{10}(s)?

• A. P_4(s) + 5 O_2(g) → P_4O_{10}(s)
• B. P_4(s) + 10 O_2(g) → 4 P_4O_{10}(s)
• C. 4 P_4(s) + 5 O_2(g) → 4 P_4O_{10}(s)
• D. P_4(s) + O_2(g) → P_4O_{10}(s)

Answer: (A)

Verified step by step guidance

1. Identify the reactants and products in the chemical reaction: elemental phosphorus (P_4) reacts with oxygen gas (O_2) to form tetraphosphorus decoxide (P_4O_{10}).
2. Write the unbalanced chemical equation: \(P_4(s) + O_2(g) \rightarrow P_4O_{10}(s)\).
3. Balance the phosphorus atoms first. Since there are 4 phosphorus atoms in P_4 and also 4 in P_4O_{10}, phosphorus is already balanced with a coefficient of 1 on both sides.
4. Balance the oxygen atoms next. There are 10 oxygen atoms in one molecule of P_4O_{10}, and oxygen gas is diatomic (O_2), so to get 10 oxygen atoms, you need 5 molecules of O_2. This gives the balanced oxygen side as \$5 O_2$.
5. Write the balanced chemical equation with the correct coefficients: \(P_4(s) + 5 O_2(g) \rightarrow P_4O_{10}(s)\).