Oxid de aluminiu: Al₂O₃
Rap. atomic: Al:O = 2:3
Rap. masic: Al:O = (2*27):(3*16) = 54:48 = 9:8
Masa moleculară: μ = 54+48 = 102 g/mol
Concentrația procentuală:
[tex]\%Al=\frac{(2*27)*100}{102}=52,94 \% \\ \\ \%O=\frac{(3*16)*100}{102}=47,05 \%[/tex]
102g Al₂O₃...............48g O
x ..............16g O x = 34g Al₂O₃
Sulfat de aluminiu: Al₂(SO₄)₃
Rap. atomic: Al:S:O = 2:3:12
Rap. masic: Al:S:O = (2*27):(3*32):(12*16)= 54:96:192 = 9:16:32
Masa moleculară: μ = 54+96+192 = 342 g/mol
Concentrația procentuală:
[tex]\%Al=\frac{(2*27)*100}{342}=15,78 \% \\ \\ \%S=\frac{(3*32)*100}{342}=28,07 \% \\ \\ \%O=\frac{(12*16)*100}{342}=56,14 \%[/tex]
342g Al₂(SO₄)₃ .............. 192g O
x ............... 16g O x = 28,5g Al₂(SO₄)₃
