Question

The reaction of $H _2 O _2$ with potassium permanganate in acidic medium leads to the formation of mainly:

• A. $Mn ^{2+}$
• B. $Mn ^{4+}$
• C. $Mn ^{3+}$
• D. $Mn ^{6+}$

Answer 1

The Correct Option is A

The reaction between hydrogen peroxide \(H_2O_2\) and potassium permanganate in an acidic medium is a redox reaction. Here, the potassium permanganate acts as an oxidizing agent while the hydrogen peroxide acts as a reducing agent. The balanced redox reaction in acidic medium is:

\(2 KMnO_4 + 5 H_2O_2 + 3 H_2SO_4 \rightarrow 2 MnSO_4 + K_2SO_4 + 5 O_2 + 8 H_2O\)

In this reaction:

• Potassium permanganate \((KMnO_4)\) is reduced from manganese in the oxidation state +7 (Mn⁷⁺) to manganese in the oxidation state +2 (Mn²⁺).
• Hydrogen peroxide \((H_2O_2)\) is oxidized to \(O_2\), releasing oxygen gas.

The reduction of \(MnO_4^-\) ions in acid to \(Mn^{2+}\) ions is the typical behavior of permanganate in acidic conditions, thus the correct answer to the given question is:

\(Mn^{2+}\)

Explanation of Options:

• \(Mn^{2+}\) (Correct): This is the product of the reaction in an acidic medium.
• \(Mn^{4+}\), \(Mn^{3+}\), and \(Mn^{6+}\) are not the common products of permanganate reduction in acidic medium.

Key Takeaways:

• In acidic medium, \(KMnO_4\) typically reduces to \(Mn^{2+}\).
• Before selecting an answer in redox reactions, it's crucial to consider the medium, as it determines the result of the redox process.
• This reaction is an example of the application of oxidation numbers and redox balancing in chemistry.