1.
SO2
S:O = 32:32 = 1:1
CO2
C:O = 12:32 = 1:2
H2SO4
H:S:O = 2:32:64 = 1:16:32
2.
MgO
Mg:O = 24:16 = 6:4
dar pt 3 g Mg
Mg:O = 3:x = 2:2
CaO are Ca:O = 40:16 = 5:2
la Ca:O = 5:2
Al203 are Al:O = 54:48 = 9:8
Al:O = 9:8
3.
calculati compozitia procent masica pentru substanta cu rapirtul de masa
Ca:C:O = 10:3:12
10+3+12 = 25 g
25 g... 10 gCa.. 3g C..... 12g O
la 100%..a%.......b%.........c%
a = 10x100/25 = 40% Ca
b = 3x100/25 = 12% C
c = 12x100/25 = 48% O
