Redox sac

[pHysiX]

Hey. I'm wondering if anyone would like to help me with this. It's for the redox sac tomorrow >.>

Anyway, i've already kinda made a flowchart of the steps in preparing for the redox titration and the steps involved as part of the process. I was wondering if anyone would like to give me their version of the necessary steps to titrate Iron(ii) to Iron (iii) using standard potassium permanganate(reduced to manganese(ii) ions) please? This is to determine the concentration of iron in a fertiliser. =]

We are told that: there will be 0.01M KMnO4 and we are to measure out 9.03 grams of fertiliser.

O and one more =]: Why is it usual practise to recored the volume of KMnO4 in a burette by reading from the top, rather than the bottom, of the meniscus?

[IntoTheNewWorld]

For the volume of KMnO4, I think it's because it's colored, so it's hard to read from the bottom.

[kurrymuncher]

For the volume of KMnO4, I think it's because it's colored, so it's hard to read from the bottom.

yeah, its a dark purple colour making it nearly impossible to read from the bottom.

LOL when we did this prac nearly everyone fucked up, because no one could get the fertilizer to properly dissolve. This meant that all the calculations were insanely innacurate. That's a good possible source of error too.

[pHysiX]

thanks. i just did the sac today. the expected titre of our setup was meant to be 10mL. we got 12mL so i think it's all good. thanks for the help!