[bamster]

I did a lab today using an iron sample solution.
I did a titration and found that it contained 0.089352g of Fe.
The question asks to express the mass as Fe₂O[/sub]3[/sub] in total sample?
How do you do this?

This is the equation for the reaction

MnO₄^-  + 5Fe²⁺ + 8H⁺      Mn²⁺  + 5Fe³⁺  + 4H₂O

It was a redox reaction for the lab but I don't know if this was it.
I know that to get the total sample is multiply it by 10 because it was a 25ml aliquot in a 250ml sample but i don know how to get it into grams of iron 3 oxide first.

[Borek]

I am not sure what you are asking about.

You know iron mass - I assume you have calculated it from the stoichiometry of titration.

If you know how to calculate stoichiometry of the titration, you should be also easily able to calculate mass of iron oxide containing given mass of iron - both calculations are based on very similar principles.

[bamster]

I really dont know how to do this.
Make an equation of adding iron to iron III oxide or something?
Give me a hint or something

[Borek]

How many moles of P in 1 mole of P₂O₅?

How many moles of P₂O₅ contain 1 mole of P?

[bamster]

How many moles of P in 1 mole of P₂O₅?

How many moles of P₂O₅ contain 1 mole of P?

so you multiply it by 2 cause there are 2 Fe's in FeIII oxide?

= 0.089910g x 2
= 0.17982 g x 1000mg x10
=1798.2 mg?

It says to put the answer in milligrams


or is it a 1:1 mole so it is the same mass?

[Borek]

so you multiply it by 2 cause there are 2 Fe's in FeIII oxide?

No. If you have two atons of Fe, how many Fe₂O₃ molecules can you make? 1, or 4?

or is it a 1:1 mole so it is the same mass?

No, it is not 1:1.

Seems like you have a terrible gaps in you stoichiometry knowledge.

[bamster]

so you multiply it by 2 cause there are 2 Fe's in FeIII oxide?

No. If you have two atons of Fe, how many Fe₂O₃ molecules can you make? 1, or 4?

or is it a 1:1 mole so it is the same mass?

No, it is not 1:1.

Seems like you have a terrible gaps in you stoichiometry knowledge.

multiply grams of fe by 1:2 ratio and then multiply by molar mass of Iron III oxide over molar mass of Fe.