Zadanie 1.
a) siarczek żelaza (III) - Fe₂S₃
Fe : S
2*56 : 3*32
112 : 96
7 : 6
b) tlenek sodu - Na₂O
Na : O
2*23 : 16
46 : 16
23 : 8
Zadanie 2.
a) MFe₂S₃ = 2*56 + 3*32 = 112 + 96 = 208 (g)
%Fe = [tex]\frac{112}{208}[/tex] * 100% = [tex]\frac{11200}{208}[/tex]% ≈ 53,8%
%S = [tex]\frac{96}{208}[/tex] * 100% = [tex]\frac{9600}{208}[/tex]% ≈ 46,2%
b) MNa₂O = 2*23 + 16 = 46 + 16 = 62 (g)
%Na = [tex]\frac{46}{62}[/tex] * 100% = [tex]\frac{4600}{62}[/tex]% ≈ 74,2%
%O = [tex]\frac{16}{62}[/tex] * 100% = [tex]\frac{1600}{62}[/tex]% ≈ 25,8%
