Raport atomic Fe(OH)3= Fe: O: H= 1:3:3
Raport atomic Ca3(PO4)2= Ca: P: O=3:2:8
Raport de masa Ca3(PO4)2= Ca : P: O=3*40:2*31:8*16 (*=inmultit)
=120:62:128
=60:31:64
Compozitie procentuala Fe(OH)3 Mfe(OH)3=1*Afe+3*Ao+3*Ah (M=masa molara; A=masa atomica) =56+3*16+3*1
=107g/mol
107g Fe(OH)3....56g Fe...48g O....3g H
100g Fe(OH)3....x% Fe....y% O...z% H
x=100*56(supra/pe)107=52.33% Fe
y=100*48(supra/pe)107=44.85% O
z=100*3(supra/pe)107=2.80% H