Răspuns:
Explicație:
Na2CO3
M= 2.23 + 12 + 3.16=106-------> 106g/moli
106 g Na2CO3---------46g Na---------12g C--------48g O
100g-----------------------x---------------------y-----------------z
x= 100 . 46 : 106=43,4% Na
y= 100.12 : 106=11,32% C
z= 100.48 : 106=45,28 % O