[natgravy]

I'm doing a redox titration where I reduce iron(III) to iron(II) using zinc powder as a reducing agent. I've read you have to completely dissolve the zinc powder in the iron(III) solution. But I need to then be able to remove the zinc(II) ions, and I think this would be really difficult.

Can I just use granulated zinc, so it's easier to remove? Will it still act as a reducing agent?

[Borek]

You don't have to remove Zn²⁺, granules are easier to remove, powder can be removed by filtration. Although it is easier to add some excess acid to dissolve the powder, you will need low pH for titration so surplus of acid is not a problem. Just select an acid that won't interfere with the titration.