[RenaHay]

A 25.0 cm3 portion of solution containing Fe2+ and Fe3+ ions was acidified and titrated against potassium managante(vii) solution. 15.00 cm3 of 00200 mol dm-3 of potassium manganate (vii) were required. A second 25.0 cm3 portion was reduced with zinc and titrated against the Same potassium manganate (vii) solution. 19.00cm3 of the oxidant solution was required.

Calculate the concentrations of
1) Fe2+
2) Fe3+  in the solution.

Hi everyone reading this. I'm rly new to redox so I don't even know how to do this question. I know it's against te forum rules to post answers, so yeah, would it be possible to let me know the steps as to how this question can be done? I'm so bad at chem that I don't even know how to form the half equations or what step to do next. Please help me, I'm not just looking for answers alone. I rly need to understand what this qn is asking. Thanks!

[Hunter2]

First develop the redox reaction equation between permanganate and iron II.
Easer to look the factors in table books.
Then compare the two titrations. One gives iron-II the other gives whole iron content. Difference will be iron-III.

[RenaHay]

Hi, pls help OMG! I don't even know how to form the half eqn.. If I use the data booklet for A levels, there's 3 equations
Fe2+ + 2e -> Fe
Fe3+ + e -> Fe2+
Fe3+ + 3e -> Fe

But if I didn't look at the booklet, the eqn I formed is
Fe2+ -> Fe3+ + e
Fe3+ -> Fe4+ + e

Ps I rly don't understand why or how the equations are formed.. Pls enlighten me :/

[Borek]

From the forum rules:

3.9. Asked on forums, answered on forums.

[Hunter2]

If we do so the tread would be censorshipped. What you already did to erase the message to get with an messager in contact to a member. Sometimes people need help to give an finished answer, in this forum not possible. And rule 3.9 is whole bu...t.
I think everybody can contact members personally by mail, chat, phone, etc and talk to them, there is no need to use this forum for it.