Chemistry Tuition – Reducing agents and oxidising agents

01 Feb Chemistry Tuition – Reducing agents and oxidising agents

Chemistry tuition classes in Miracle Learning Centre is easy to understand and help you in the chemistry tuition application questions. If you do not understand chemistry in school, you must definitely come for chemistry tuition classes at Miracle Learning Centre. Let us learn about reducing agents and oxidising agents in this Chemistry lesson.

The chemistry tuition teachers at Miracle Learning Centre will teach you how reducing agents will react with oxidising agents. Let us learn what a reducing agent and oxidising agent is.

The reducing agent is substance that reduces another substance but is itself oxidised. On the other hand, oxidising agent oxidises another substance but is itself reduced.

Let us look at the specific examples for reducing agent and oxidising agent. A common example would be when chlorine reacts with potassium iodide to form potassium chloride and iodine. Chlorine has been reduced as the oxidation state of chlorine decreases from 0 in chlorine to -1 in potassium chloride. Hence, we say that chlorine has been reduced. Potassium iodide on the other hand has been oxidised. Iodine in potassium iodide has an oxidation state of -1 and it increases to 0 in iodine. Hence there is an increase in oxidation state from -1 to zero and hence potassium iodide has been oxidised.

An oxidising agent as we have learn before, is a substance that oxidises another substance but itself reduced. In this reaction, we notice that chlorine is the oxidising agent. Chlorine oxidises potassium iodide to become iodine, and itself reduced. Any substance that has been reduced is an oxidising agent. To have a more complete answer, we would need to explain that chlorine oxidises potassium iodide to iodine and causes iodine to have an increase in oxidation state from -1 to 0. Hence potassium iodide has been oxidised. Chlorine itself has been reduced, as its oxidation state has decreased from 0 to -1. That is the full definition of an oxidising agent in this reaction. On the other hand, potassium iodide is a reducing agent. Potassium iodide has reduced chlorine to become potassium chloride and itself oxidised to become iodine.

Jamie, a student at Miracle Learning Centre asked, “Why do we need to learn about oxidising agents and reducing agents?”

Mrs Lew, the chemistry tuition teacher at Miracle Learning Centre replied, “Oxidising agents can be used to identify reducing agents. This is because oxidising agents reacts with reducing agents in a redox reaction. In order to identify a reducing agent, we use an oxidising agent for example, acidified potassium permanganate(VII) changes from purple to colourless when it is added to a reducing agent. This can be used to identify a reducing agent. Another common oxidising agent used is acidified potassium dichromate(VI). Acidified potassium dichromate(VI) changes from orange to green when it is added to a reducing agent. On the other hand, to identify an oxidising agent, you will need to use a reducing agent. A reducing agent, potassium iodide, is used to identify an oxidising agent. Potassium iodide changes from colourless to brown as iodine is formed. Hence it is oxidised. Therefore, potassium iodide is a reducing agent.

Miracle Learning Centre hopes you have understood this lesson on redox reactions involving reducing agents and oxidising agents. Do come to Miracle Learning Centre for more chemistry tuition lessons to learn about reducing agents and oxidising agents.

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