*The answer might be different if you are using a different Periodic Table, but it should be similar.
Al2(SO4)3
2 Aluminum atoms
3 Sulfur atoms
12 Oxygen atoms
Find the mass of Al2(SO4)3
Aluminum = 26.98 g
Sulfur = 32.07 g
Oxygen = 16.00 g
2(26.98)+3(32.07)+12(16.00)
53.96+96.21+192.0
342.2 g = mass of Al2(SO4)3
Divide the total mass of Sulfur atoms in the molecule by the mass of the molecule
96.21/342.2
0.2812
Multiply by 100 to have a percentage.
28.12
The mass percent composition of Sulfur in Al2(SO4)3 is 28.12%.
