Which of the following chemical reactions involves the fewest oxygen atoms in the reactants?

• A. 2Na + Cl2 → 2NaCl
• B. 2H2 + O2 → 2H2O
• C. 2CO + O2 → 2CO2
• D. C + O2 → CO2

Answer: (A)

Verified step by step guidance

1. Identify the number of oxygen atoms present in the reactants of each given chemical reaction.
2. For the reaction \$2Na + Cl_2 \rightarrow 2NaCl$, note that there are no oxygen atoms in the reactants because neither sodium (Na) nor chlorine gas (Cl_2) contains oxygen.
3. For the reaction \$2H_2 + O_2 \rightarrow 2H_2O\(, count the oxygen atoms in the reactants: \)O_2$ contains 2 oxygen atoms.
4. For the reaction \$2CO + O_2 \rightarrow 2CO_2\(, count the oxygen atoms in the reactants: each \)CO\( molecule has 1 oxygen atom, so 2 \)CO\( molecules have 2 oxygen atoms, plus 2 oxygen atoms from \)O_2$, totaling 4 oxygen atoms.
5. For the reaction \(C + O_2 \rightarrow CO_2\), count the oxygen atoms in the reactants: \(O_2\) contains 2 oxygen atoms.
6. Compare the total oxygen atoms in the reactants of each reaction to determine which has the fewest.