Step 1
The chemical formula of iron (III) sulfate is the next one:
Fe2(SO4)3
As we can see, there are 3 x 1 atom of S, 3 atoms of S
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Step 2
Information needed:
The atomic masses of:
Fe) 55.8 g/mol
S) 32.0 g/mol
O) 16.0 g/mol
(Please, the periodic table is useful here)
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Step 3
The % of S in Fe2(SO4)3 is calculated as follows:
[tex]\frac{3\text{ x 32.0 g/mol of S}}{(2\text{ x 55.8 g/mol Fe + 3 x 32.0 g/mol S + 3 x 4 x 16.0 g/mol O\rparen}}x100\text{ = 24.0 \%}[/tex]Answer: 24 % of S
