Which of the following is NOT a redox reaction?

Step-by-step solution

In the reaction Zn + H ₂ SO ₄ ZnSO ₄ + H ₂ , the oxidation state of Zn changes from 0 to +2 and H changes from +1 to 0 . It is a redox reaction. In the reaction Al(OH) ₃ + 3 HCl AlCl ₃ + 3 H ₂ O , the oxidation states of all elements remain the same (Al is +3 , O is -2 , H is +1 , Cl is -1 ). It is an acid-base neutralization reaction, not a redox reaction. In the reaction Mg + 1/2 O ₂ Mg ²⁺ + O ²⁻ , the oxidation state of Mg changes from 0 to +2 and O changes from 0 to -2 . It is a redox reaction. In the reaction