Which of the following are the chemical products formed when methane (CH_4) undergoes complete combustion in oxygen?

• A. C and H_2O
• B. CH_3OH and O_2
• C. CO_2 and H_2O
• D. CO and H_2

Answer: (C)

Verified step by step guidance

1. Understand that complete combustion of a hydrocarbon like methane (CH_4) means it reacts fully with oxygen (O_2) to produce carbon dioxide (CO_2) and water (H_2O).
2. Write the general balanced chemical equation for the complete combustion of methane: \(\mathrm{CH_4 + O_2 \rightarrow CO_2 + H_2O}\).
3. Balance the carbon atoms first: methane has 1 carbon, so produce 1 molecule of CO_2.
4. Balance the hydrogen atoms next: methane has 4 hydrogens, so produce 2 molecules of H_2O (since each water molecule has 2 hydrogens).
5. Finally, balance the oxygen atoms: count oxygen atoms on the product side (2 from CO_2 and 2 from 2 H_2O = 4 oxygens), so you need 2 O_2 molecules on the reactant side to supply 4 oxygen atoms.