I did an experiment involving the gravimetric determination of Iron in Geritol.

At the end of the experiment I was left with a product, Fe[sub]2[/sub]O[sub]3[/sub] that weighed 0.417 g

I'm not sure how to calculate the amount of Iron from here.

This is what I did.
I calculated the molar mass of Fe[sub]2[/sub]O[sub]3[/sub] to be 159.6922 g.
Then I figured that Fe[sub]2[/sub]O[sub]3[/sub] was 69.9433% Fe.

So i multiplied the weight of my product with the % to get 0.28096 g of Fe in my product.

Does this make any sense??

The manufacturer's analysis of Geritol says there should be 60 mg of elemental Iron per tablet.
(my sample contained two tablets)

Are my calculations wrong? Or did I mess up the experiment? ???

Please help ASAP!
THANKS!

wthai

I checked your calculations and they seem to be correct.
If you got your Fe2O3 by precipitation, perhaps you need to add more of the substance used to precipitate out the Fe203 just so that u get all the Fe out of the solution. Also when you write out the equation of the reaction, did you balance it? maybe you didn't take into consideration the number of moles of Fe2O3 you got in the end.

pavani

A company's normal capacity utilization is reckoned as 90%, it has a production capacity of 200000 units per year. Standard variable production cost and the variable selling cost are Rs. 11 and Rs. 3 per unit respectively. However the fixed cost and the fixed selling cost are rs. 360000 and Rs. 270000 per year respectively. the unit selling price is Rs. 20. In the year just ended on 31 December 2006, the production was 160000units and the sale was 150000 units. The closing inventory on 31st Dec was 20,000 units. the actual variable production costs for the year were Rs. 35,000 higher than the standard.

Calculate the profit for the year,
a) Marginal costing method.
b) absorption costing method