Răspuns:
Explicație:
Fe2(SO4)3
M= 2 . 56 + 3 . 32 + 12 . 16=400 -----> 400g/moli
400g Fe2(SO4)3--------112 g Fe ------96 g S ---------192g O
100 g-----------------------------x---------------------y------------z
x= 100 . 112 : 400 = 28 % Fe
y=100 .96 : 400 = 24 % S
z= 100 .192 : 400 = 48% O
