oxidising & reducing agents

• Oxidizing agents are substances that oxidize another substance but themselves are reduced
• Reducing agents are substances that reduce another substance but themselves are oxidized
• In a reaction, the easiest way to spot the oxidizing agent is to look for the substance that is reduced
• In a reaction, the easiest way to spot a reducing agent is to look for the substance that is oxidized
• An oxidizing agent donates oxygen to another substance and is reduced
• An oxidizing agent accepts hydrogen from another substance
• An oxidizing agent accepts electrons from another substance
• A reducing agent accepts oxygen from another substance and is oxidized
• A reducing agent donates hydrogen to another substance and is oxidized
• A reducing agent donates electrons to another substance and is oxidized
• Common oxidizing agents to remember in the syllabus are acidified potassium permanganate (KMnO4) and acidified potassium dichromate (K2Cr2O7)
• Acidified means an acid has been added to make the solution acidic, making the oxidizing agent more powerful
• A common reducing agent to remember is potassium iodide (KI)
• When acidified potassium permanganate acts as an oxidizing agent, it is reduced to Mn2+
• When acidified potassium permanganate is reduced, there is a color change from purple to colorless
• When acidified potassium dichromate acts as an oxidizing agent, it is reduced to Cr3+
• When acidified potassium dichromate is reduced, there is a color change from orange to green
• When potassium iodide acts as a reducing agent, it is oxidized to iodine
• When potassium iodide is oxidized, there is a color change from colorless to brown
• To confirm the presence of an oxidizing agent, add a reducing agent and observe a color change
• To confirm the presence of a reducing agent, add an oxidizing agent and observe a color change