stiu ca 1 mol particule (molecule,sau atomi) contine :
N,Avogadro= 6,023x1o²³ particule(molecule sau atomi)
H2 + CL2------------> 2 HCl
1molH2 1molCl2 2molHC l
1molH2 contine 2mol atomiH, deci N= 2molx6,023x10²³atomiH/mol
1molCl2 2mol atomi Cl, N= 2molx6,023x10²³ atomi Cl/mol
2molHCl contin 2 moli molecule HCl
2 moliHCl contin 2moliatomiH si 2 moli atomi Cl, deci acelasi numar de atomi care intra in reactia---> legea conservarii numarului de atomi