MHT CET Chemistry Question (2026) — Solution

Step-by-step solution

A redox reaction involves a change in the oxidation states of the elements involved. In the reaction Cl _2 + 2 H _2 O + SO _2 4 H ^+ + SO _4^ 2- + 2 Cl ^-, the oxidation state of Cl changes from 0 to -1 and S changes from +4 to +6. This is a redox reaction. In the reaction Cu ^ 2+ + Zn Cu + Zn ^ 2+ , the oxidation state of Cu changes from +2 to 0 and Zn changes from 0 to +2. This is a redox reaction. In the reaction 2 H _2 + O _2 2 H _2 O , the oxidation state of H changes from 0 to +1 and O changes from 0 to -2. This is a redox reaction. In the reaction HCl + H _2 O H _3 O ^+ + Cl ^-, the oxidation state of H remains +1, Cl remains -1, and O remains -2. Since there is no change in the oxidation state of any element, this is an acid-base reaction and not a redox reaction. Answer: HCl + H _2 O H _3 O ^+ + Cl ^-