Răspuns:
Explicație:
1.
CuSO4
a. prin masa moleculara
M= 64 + 32 + 4.16=160--------> 160g/moli
160g CuSO4-------64g Cu------32 g S---------64g O
100 g-----------------------x-------------y-----------------z
x= 100.64 : 160=40% Cu
y=100 . 32 : 160=20% S
z= 100.64 : 160= 40% O
b. prin raport de masa
r.m.= 64 : 32 : 64 se simpl. cu 32
=2 : 1 : 2
2+ 1 +2=5
5g CuSO4--------2g Cu--------1gS ---------2g O
100g---------------------x--------------y------------z
x=100.2: 5 =40% Cu
y= 100. 1 : 5=20%S
z= 100 .2 : 5=40% O
2.
MCaCO3=40+12+3.16=100-------> 100g/moli
100 g CaCO3---------12g C
25g CaCO3------------x
x= 25 .12 : 100 = 3g C