Which of the following are the products formed when methanol (CH3OH) undergoes complete combustion in excess oxygen?

• A. C and H2O
• B. CO2 and H2O
• C. CO and H2O
• D. CH4 and O2

Answer: (B)

Verified step by step guidance

1. Identify the reactants and products in a combustion reaction. Complete combustion of a hydrocarbon or alcohol involves reacting the compound with excess oxygen (O2) to produce carbon dioxide (CO2) and water (H2O).
2. Write the general form of the complete combustion reaction for methanol (CH3OH): \(\mathrm{CH_3OH} + O_2 \rightarrow CO_2 + H_2O\)
3. Balance the chemical equation by ensuring the number of atoms of each element is the same on both sides. Start by balancing carbon (C), then hydrogen (H), and finally oxygen (O).
4. Confirm that the products are carbon dioxide (CO2) and water (H2O), which are typical products of complete combustion of organic compounds containing carbon and hydrogen.
5. Recognize that incomplete combustion would produce carbon monoxide (CO) or other products, but since the problem specifies complete combustion in excess oxygen, the correct products are CO2 and H2O.