[bornn]

I think i got these titration-calculations down but just to sure I did this correctly

For this experiment I preformed a rebox titation with potassium dichromate to analyze iron oxide samples

so first i prepared the potassium dichromate solution and calculated the molarity of the solution:

2.49g k2CrO7 X (1mole/294.185g KsCr2O7)=.008464 mole K2Cr2O7

molarity .008464 mole K2Cr2O7/0.500L=.016928 or .017M

Then for the first trial

.4227g of Fe2O3
43.50 mL of K2Cr2O7

according to the equation its a 6:1 ratio

.04350 L X .017M=7.395X10^-4 moles of K2Cr2O7

7.395X10^-4 X 6 =.004437 moles of Fe

.004437 mol of Fe X 55.847g/mol=.247793 g

.247793 g / .4227g X 100=58.6% Fe in the iron ore sample

are these calculations correct I have a feeling I am forgetting something.

thanks in advanced

[Borek]

Looks OK to me.