Question

Hey - having to do a back titration for determination of %chromium in a chromite sample... in the conical flask is standard AIS (ammonium iron (II) sulfate) solution, indicator, acids, and the chromite sample which has been treated with peroxide and ammonium chloride..... How do I use all of this to get the moles etc of chromium? :/ any ideas?

Answer 1

Also, the titre was K_2Cr_2O_7 solution...

Answer 2

All I really know at this stage is the dichromate half equation, and the chromite/peroxide reaction \[2Fe(CrO_2)_2 + 7O_2^2 --> 2FeO_2 + 4CrO_4 ^2 + 2O^2\](except with -2 powers... for some reason wouldnt format that correctly)

Answer 3

Use this equation:
\[M_1V_1=M_2V_2\]
Where M and V represents Molarity and Volume, respectively, of solution 1 and 2.

Answer 4

I can't address the chemistry question but for powers use: ^{} where you put the full negative number in the parentheses.