Chemistry Q65 – NEET-UG 2026

Home Chemistry Redox ReactionsQuestion #561

Given below are two statements: Statement-I : Heating NaCl with concentrated H

_{2}

_{4}

and MnO

_{2}

results in oxidation of Mn. Statement-II : Heating NaI with concentrated H

_{2}

_{4}

and MnO

_{2}

results in reduction of Mn. In light of the above statements, choose the most appropriate answer from the options given below:

Clue 1 of 3: Redox Reactions

This question involves identifying the change in oxidation states of manganese in a chemical reaction.

🥷

Ninja Strategy•Oxidation State Analysis

Quickly determine the oxidation state of Mn in the reactant (MnO $_{2}$ ) and the product (MnSO $_{4}$ ) to identify if Mn is oxidized or reduced, then evaluate each statement.

🧠 Full Solution Path

Step 1: Determine Oxidation State of Mn in Reactant✦ Active

In the reactant, MnO $_{2}$ , oxygen typically has an oxidation state of -2. Since there are two oxygen atoms, the total negative charge is $- 4$ . To maintain neutrality, manganese (Mn) must have an oxidation state of $+ 4$ .

Step 2: Determine Oxidation State of Mn in Product○ Expand

When NaCl or NaI is heated with concentrated H $_{2}$ SO $_{4}$ and MnO $_{2}$ , the manganese compound formed is manganese(II) sulfate, MnSO $_{4}$ . In MnSO $_{4}$ , the sulfate ion ( ${SO}_{4}^{2 -}$ ) has a charge of -2. Therefore, manganese (Mn) must have an oxidation state of $+ 2$ to balance the charge.

Step 3: Evaluate Statements based on Oxidation State Change○ Expand

For both reactions, Mn changes its oxidation state from $+ 4$ (in MnO $_{2}$ ) to $+ 2$ (in MnSO $_{4}$ ). A decrease in oxidation state signifies reduction. Therefore, Mn is reduced in both reactions.

Statement-I: "Heating NaCl with concentrated H $_{2}$ SO $_{4}$ and MnO $_{2}$ results in oxidation of Mn." This is incorrect, as Mn is reduced.

Statement-II: "Heating NaI with concentrated H $_{2}$ SO $_{4}$ and MnO $_{2}$ results in reduction of Mn." This is correct, as Mn is reduced.

Based on this, Statement-I is incorrect, and Statement-II is correct.

💡 Teacher's Secret Hint

Remember that oxidation is an increase in oxidation state, and reduction is a decrease in oxidation state.

✦ STEM Console utilizes AI models to generate step-by-step explanations and math clues. AI can make mistakes.

Chemistry Question 65 – NEET-UG 2026

Clue 1 of 3: Redox Reactions

🧠 Full Solution Path