MHT CET Chemistry Question (2026) — Solution

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 Fe _ (s) + Cu ^ 2+ _ (aq) Fe ^ 2+ _ (aq) + Cu _ (s) , the oxidation state of Fe changes from 0 to +2 and Cu changes from +2 to 0. It is a redox reaction. Answer: Al(OH) _3 + 3 HCl AlCl _3 + 3 H _2 O