Consider the following reaction: CH₄ + 2O₂ → CO₂ + 2H₂O Which of the f

Consider the following reaction: CH₄ + 2O₂ → CO₂ + 2H₂O
Which of the following about the reaction given above is/are correct ?

  • 1. Carbon is oxidized.
  • 2. Hydrogen is oxidized.
  • 3. Hydrogen is reduced.
  • 4. Carbon is reduced.

Select the correct answer using the code given below :

1 only
1 and 2 only
2 and 3 only
2 and 4 only
This question was previously asked in
UPSC NDA-2 – 2017
Statement 1 is correct: Carbon is oxidized. Statements 2, 3, and 4 are incorrect.
Oxidation is the process where an atom or molecule loses electrons or increases its oxidation state. Reduction is the process where an atom or molecule gains electrons or decreases its oxidation state. In the given reaction (combustion of methane), let’s look at the oxidation states:
– In CH₄: Hydrogen is +1, so Carbon is -4 (since CH₄ is neutral).
– In O₂: Oxygen is 0 (elemental form).
– In CO₂: Oxygen is -2, so Carbon is +4 (since CO₂ is neutral).
– In H₂O: Hydrogen is +1, so Oxygen is -2 (since H₂O is neutral).
Carbon’s oxidation state changes from -4 to +4 (increase), so Carbon is oxidized.
Hydrogen’s oxidation state remains +1 (no change), so Hydrogen is neither oxidized nor reduced.
Oxygen’s oxidation state changes from 0 to -2 (decrease), so Oxygen is reduced.
This reaction is a classic example of a redox (reduction-oxidation) reaction. Methane (CH₄) acts as the reducing agent (gets oxidized), and Oxygen (O₂) acts as the oxidizing agent (gets reduced). Combustion reactions are typically redox reactions where a fuel is oxidized rapidly, usually releasing heat and light.