Question

Hydrogen peroxide in its reaction with \(\mathrm{KIO}_{4}\) and \(\mathrm{NH}_{2} \mathrm{OH}\) respectively, is acting as a (A) reducing agent, oxidising agent (B) reducing agent, reducing agent (C) oxidising agent, oxidising agent (D) oxidising agent, reducing agent

Short answer

(D) oxidising agent, reducing agent

Step-by-step solution

Understand Redox Reactions

Recognize the terms 'oxidizing agent' and 'reducing agent'. An oxidizing agent gains electrons and is reduced, while a reducing agent loses electrons and is oxidized.

Determine the Role of Hydrogen Peroxide with KIO4

Write the half-reaction for hydrogen peroxide (H2O2) when it reacts with KIO4. Hydrogen peroxide tends to lose electrons (oxidized) and thus acts as a reducing agent.

Determine the Role of Hydrogen Peroxide with NH2OH

Write the half-reaction for hydrogen peroxide (H2O2) when it reacts with NH2OH. In this reaction, hydrogen peroxide gains electrons (reduced) and acts as an oxidizing agent.

Analyze the Results

Compare the roles of hydrogen peroxide in both reactions. In the first case, it's a reducing agent, and in the second case, it's an oxidizing agent.

Key concepts

Oxidizing Agent

In redox chemistry, an oxidizing agent is a substance that has the ability to accept electrons from another species. During this process, the oxidizing agent itself gets reduced. For students tackling JEE Advanced chemistry problems, understanding the role of an oxidizing agent is crucial as it often underpins the mechanism of the chemical reactions. A classic example is hydrogen peroxide (H₂O₂) acting as an oxidizing agent when it reacts with hydroxylamine (NH₂OH). Here, the hydrogen peroxide gains electrons and is therefore reduced.
In analyzing such reactions, focusing on the transfer of electrons can greatly assist in determining the role of each reactant. It's important to remember that in a redox reaction, there is always a pair of reactions: one species is oxidized and the other is reduced. Visualization tools like oxidation number changes can be particularly helpful in identifying the oxidizing agent in a reaction.

Reducing Agent

In contrast to an oxidizing agent, a reducing agent donates electrons and becomes oxidized itself. Students studying for competitive exams like JEE Advanced need to be adept at recognizing reducing agents in chemical reactions. Using hydrogen peroxide as an example, when it reacts with potassium periodate (KIO₄), hydrogen peroxide donates electrons – it is oxidized – making it the reducing agent in this reaction.
Understanding the concept of reducing agents is also key in predicting the outcomes of redox reactions. Always check the direction of electron flow to identify which compound is giving up electrons. This understanding will support problem-solving in practical applications such as corrosion, battery design, or even metabolic pathways in biochemistry.

Half-Reactions

Redox reactions can be broken down into half-reactions to show the separate oxidation and reduction processes. Each half-reaction shows either the loss or gain of electrons explicitly. This method is especially useful when preparing for exams like the JEE Advanced, as it allows for a stepwise approach to complex reactions. By analyzing the half-reactions for hydrogen peroxide's interactions with both KIO₄ and NH₂OH, its dual role as both an oxidizing and reducing agent is revealed.
Students should practice writing half-reactions to clearly illustrate the electron transfer process. This practice solidifies the student’s grasp of oxidation states and the identification of species being oxidized or reduced. The technique is also beneficial for balancing overall redox reactions, making it a fundamental skill in chemistry.

Chemical Reactions in JEE Advanced

Competitive exams like the JEE Advanced require a deep understanding of chemical reactions, particularly redox reactions. These reactions are integral to numerous fields of chemistry, from electrochemistry to biochemistry, and proficiency in them is a must for any aspiring engineer or scientist.
Preparing for questions on redox chemistry involves not just memorization but also the ability to apply concepts to novel situations. This learning includes the roles of oxidizing and reducing agents, the breakdown of reactions into half-reactions, and the ability to balance and predict the outcomes of these reactions. Remember, conceptual clarity, coupled with problem-solving skills and time management, is the essence of cracking the JEE Advanced. Hence, regularly practicing redox reaction problems, and understanding the underlying principles, like those involving hydrogen peroxide, can boost a student’s performance in the examination.