Question

Cate molecule se gasesc in 9g apa ? Dar in 10,6 g carbonat de sodiu ?

Answer 1

NA=6,022*10^23 molecule
m=masa,g
M=masa moleculara,g/mol
MH2O=2+16=18g/mol
nr moli=m/M=9/18=0.5 moli apa
nr molecule=nr moli * NA(nr lui Avogadro)=0.5*6.022*10^23=3.011*10^23 molecule
MNa2CO3=23*2+12+48=106g/mol
nr moli=m/M=10.6/106=0,1 moli Na2CO3
nr molecule=nr moli* NA=0.1*6.022*10^23=6.022*10^22 molecule