Question

Ajutor va rog .Am o problema la chimie : 
in compusul Na2CO3 , procentul de carbon este... ? 

Answer 1

CnH2n+2 + O2 -> CO2 + H2O

44g CO2......12g C
0,88g CO2 ....xg C => x=10.5 g C

18g H2O......2g H2
0.45g H2O....yg Hs => y=0.05 g H2

Answer 2

masa moleculara a lui Na2CO3=106 g/mol
In 106 gNa2CO3.............12g C
    100g..........................x
⇒x=1200/106=11.32% C