Na2CO3
M=( 2X23gNa +12gC+3X16gO)/mol= 106g/mol
Na:C:O=2:1:3
mNa :mC :mO= 2X23: 12: 3X16
= 46 : 12 : 48 SE simplifica cu 2
= 23: 6: 24
in 106g Na2CO3..........46gNa.....12gC......48gO
100g..........................x..................y..............z
calculeaza x,y,z, !!!!!!