Determine the simplest formula for compounds that have the following analyses. The data may not be exact.

A.
28.5% iron, 48.6% O, 22.9% S

This is what I did:
28.5g Fe 1 mole Fe/55.847g = .51 mole
48.6g O 1 mole O/15.999g = 3.04 mole
22.9g S 1 mole S/32.064g = .71 mole

(Fe1.0 O6.0 S1.4)5 = Fe5 O30 S7

is that right? can you please help me check my answer?

I don't get it either. But overall, did i get my calculation right? or did i do the process right?

The process looks ok to me. The statement about not being exact but the percentages add to 100.0 (plus few of us have heard of Fe5S7O30)makes me think that the problem was made up.

The thing that strikes me is the sum of the compositions is exactly 100 percent, yet the problem says it may not be exact. So if Fe were reduced by .6gram, and S were increased by .6 gram. ... one gets Iron(II) sulfite

yea they are completely made up.

To determine the simplest formula for a compound, you need to find the ratio of atoms in moles. From your calculations, you have obtained the following:

Fe = 0.51 moles
O = 3.04 moles
S = 0.71 moles

Now, to find the simplest ratio, you can divide each of these values by the smallest value (in this case, Fe):

Fe/Fe = 0.51/0.51 = 1
O/Fe = 3.04/0.51 ≈ 6 (rounded to nearest whole number)
S/Fe = 0.71/0.51 ≈ 1.4 (rounded to one decimal place)

So, the simplest ratio for Fe, O, and S is approximately Fe1 O6 S1.4.

To convert this approximate ratio to whole numbers, you can multiply through by 10 to eliminate the decimal and get Fe10 O60 S14. However, in a simplest formula, subscripts should be in their smallest whole-number ratio. To achieve this, you can divide all the subscripts by the lowest whole-number subscript (in this case, Fe1):

Fe10/Fe1 = 10/1 = 10
O60/Fe1 = 60/1 = 60
S14/Fe1 = 14/1 = 14

Therefore, the simplest formula for the compound with the given analysis is Fe10O60S14.