Which of the following reactions represents the combustion of methane?

Correct option is A

The correct answer is (a) CH4 + 2O2 -> CO2 + 2H2O

Explanation:

• Combustion is a chemical process where a substance reacts rapidly with oxygen (O2), releasing energy in the form of heat and light.

• Methane (CH4) is an alkane and the simplest hydrocarbon; when it burns in a sufficient supply of oxygen, it undergoes complete combustion.

• The products of complete combustion for any hydrocarbon are carbon dioxide (CO2) and water (H2O).

• The balanced chemical equation for this reaction is:

  CH4 + 2O2 -> CO2 + 2H2O + Heat * This reaction is highly exothermic, meaning it releases a significant amount of energy, which makes methane an excellent fuel source.

Information Booster:

• Incomplete Combustion: If oxygen is limited, the reaction produces Carbon Monoxide (CO) or soot (Carbon), which is dangerous and less energy-efficient.

• Oxidation: Combustion is a specific type of oxidation reaction where the carbon in the fuel is oxidized to CO2 and the hydrogen is oxidized to H2O.

• Ignition Temperature: For combustion to begin, methane must reach its ignition temperature in the presence of an oxidant (oxygen).

Additional Knowledge:

• Option B (CH4 + H2O -> CO + 3H2): This is the Steam Methane Reforming process, primarily used to produce industrial hydrogen gas.

• Option C (CH4 + Cl2 -> CH3Cl + HCl): This represents a Substitution Reaction (specifically halogenation) which typically requires UV light to proceed, not a combustion process.

• Option D (CH4 + O2 -> CO + H2O): This represents Incomplete Combustion, which occurs when the oxygen supply is restricted, leading to the formation of toxic carbon monoxide.