[vijayamac]

Hi,

I have a major test in elctrochemistry unit.

can you PLEASE answer this question ASAP.Thank you so mcuh

In an acidic solution MnO4- reacts with Sn2+ to give Sn4+ and Mn2+

a.Write a balanced equation for the reaction
b.38.62 mL of 0.100M solution of KmnO4  is needed to titrate 40.0ml of  Sn2+  solution. How many moles of  Sn2+  are present in the solution?


I know the answer for the first part fo tehe question. can you answer the (b) part?

[Borek]

Twice the Nernst equation - for both half reactions. Both potentials must be identical. Plus some stoichiometry from the balanced reaction equation that you already have. That'll give you set of equations. Solve. Done.

[vijayamac]

Thanks for your reply

My balanced eqaution is
5 Sn2+  +  16H+  +     2MnO4- ----> 5 Sn4+  +2Mn2+   +8H2O

We haven't learnt Nernst equation. This problem is under Redox Stoic.

It would be very helpful if you an solve and give me the final answer. I am struggling in my AP Chem class.

Thanks again

[Borek]

If you don't know the Nernst equation all you have to do is simple stoichiometry. Start calculating amount of permanganate, then calculate amount of tin, then convert it to concentration.

[weng555]

Why do we have to change to the form concentration when the question wants moles?

[Borek]

Why do we have to change to the form concentration when the question wants moles?

Sorry, my mistake. Amount of tin is the final answer. I was under impression that you are asked about the tin concentration. Probably because the tin solution volume was given.