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# Moles Question Watch

1. State the number of moles of sulfur atoms, S, in 0.3 mol iron(III) sulfate, Fe2(SO4 )3.

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I'm at a loss on how to do this question because I cant use either of the formulas M=cv/100 / and the mass given / Mr one
2. How many sulfur atoms are there in the compound? Then how many moles will that make in 0.3 moles of the compound?
3. The question is missing a lot of information.
How many sulfur atoms are there in the compound? Then how many moles will that make in 0.3 moles of the compound?

Do you do the Mr x avogadro to find the number of atoms?
5. Fe2(SO4)3 -> how many atoms of sulphur are there in the compound?

you dont need to use Avogadro, you are making this more complicated than it needs to be!
Fe2(SO4)3 -> how many atoms of sulphur are there in the compound?

you dont need to use Avogadro, you are making this more complicated than it needs to be!
Is it Ar of sulphur divided by the total Mr?
7. There are x sulphurs per one compound. Thus if we multiply x by 0.3, we should get the moles of sulphur atoms.
8. (Original post by l4ith)
There are x sulphurs per one compound. Thus if we multiply x by 0.3, we should get the moles of sulphur atoms.
Howd you find how much in one compound ?
9. (Original post by The Smeezington)
The question is missing a lot of information.
nope, you've got exactly what info you need.

(Original post by Gelato)
Is it Ar of sulphur divided by the total Mr?
Again, FAR too complicated.

Fe2(SO4)3

What does the chemical formula tell you about the compound?
nope, you've got exactly what info you need.

Again, FAR too complicated.

Fe2(SO4)3

What does the chemical formula tell you about the compound?
It tells you there are 2 atoms of Fe , 3 atoms of Sulphur and 12 of Oxygen ?
11. I think there are clinics where you can get them lasered off. Not sure how safe it is though

12. (Original post by Gelato)
It tells you there are 2 atoms of Fe , 3 atoms of Sulphur and 12 of Oxygen ?
So if there are 3 atoms of sulphur in 1 molecule, how many moles of sulphur are there in 0.3 moles of molecules?
So if there are 3 atoms of sulphur in 1 molecule, how many moles of sulphur are there in 0.3 moles of molecules?
I'm still confused ,how can you calculate the moles without any mass given ?
14. (Original post by Gelato)
I'm still confused ,how can you calculate the moles without any mass given ?
You dont need it. If i have 15 cars, how many wheels are there? If i have 0.3moles of Iron (III) Sulphate how many moles of Sulphur do i have?
15. Is it 0.3 x 3 ?

As 0.3 moles of iron sulphate x 3 atoms that are present ?
16. (Original post by Gelato)
Is it 0.3 x 3 ?

As 0.3 moles of iron sulphate x 3 atoms that are present ?
YAY! Correct!

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Updated: December 23, 2010
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