Which of the following is a redox reaction, but not a combination reaction ?

Which of the following is a redox reaction, but not a combination reaction ?
  1. C + O2 → CO2
  2. 2 H2 + O2 → 2 H2O
  3. 2 Mg + O2 → 2 MgO
  4. Fe2O3 + 3 CO → 2 Fe + 3 CO2

Solution

Fe2O3 + 3CO → 2Fe + 3CO2

Asked in: CBSE

Practice more CHEMICAL REACTIONS AND EQUATIONS questions on Aicharya