yep that is what I got
A 25.0 cm3 sample of a solution containing both Fe2+ and Fe3+ ions was acidified and titrated with 0.022 mol dm-3 manganate (VII) solution (containing the MnO4- ion) requiring 15.0 cm3. A second sample of the same solution was treated with excess Zn to reduce all the Fe3+ to Fe2+ and then, after filtering, was titrated against the same permanganate solution requiring 19.0 cm3.
a) Write down balanced half equations for the following
i) MnO4- is reduced to Mn2+ in acid conditions
ii) Zn is oxidized to Zn2+
iii) Fe3+ is reduced to Fe2+
iv) Fe2+ is oxidized to Fe3+ (4 marks)
b) In the first titration only the Fe2+ reacts with acidified MnO4-. Use this information, and a balanced net overall redox reaction, to calculate the concentration of Fe2+ in the solution. (4 marks)
c) With the second sample the zinc reacts with Fe3+ to Fe2+. Write a balanced equation for this reaction. (1 mark)
d) After all the Fe3+ has been converted to Fe2+ it is then titrated again with acidified MnO4-. Calculate the concentration of Fe2+ at this point and use this value, and your answer to b), to calculate the concentration of Fe3+ present in the solution before the zinc was added. (5 marks)
e) Why is it necessary to filter off the zinc before the second titration takes place? (1 mark)
we did the calculation part , can you do a)c)e)
to see if my answer is same as urs