# Redox Reaction

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## Homework Statement

Excess acidified potassium permanganate is added dropwise to an ammonium iron(II) sulfate solution. Write an overall redox equation for this process.

2. The attempt at a solution
Well I am not really sure what to do. I don't know what products are being formed. What should i do in a situation like this?

## Answers and Replies

Stevedye56
Start with a balanced equation. Were you given the rules to follow for a redox reaction?

Staff Emeritus
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What is the one thing that you neeed to know about potassium permanganate?

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How do i write a balanaced equation though? I don't know what the products are

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What is the one thing that you neeed to know about potassium permanganate?

Its soluble in water?

Staff Emeritus
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Lots of things are soluble in water.

I quote from the first paragraph of the wiki on potassium permanganate:

Potassium permanganate is the chemical compound KMnO4. In this salt, manganese is in the +7 oxidation state. The salt is also known as "permanganate of potash" and "Condy's crystals". The permanganate ion is a strong oxidizing agent. It dissolves in water to give deep purple solutions, evaporation of which gives prismatic purple-black glistening crystals. It has a sweet taste and is odourless.

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Ok, so its an oxidising agent, and therefore, itself reduced. I think this is the correct equation for its reduction:

$$MnO_4 ^ - _{(aq)} + 8H^ + _{(aq)} + 5e^ - \to Mn^{2 + } _{(aq)} + 4H_2 O_{(l)}$$

Would i just combine that with the half equation of iron (II) being oxidised to iron (III) ions?

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Yup, you got it!

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Ahh ok. Thanks :)