Răspuns:
ACa=40 AMg =24 ACl=35,5
Explicație:
a. n =m : M ; n=nr.moli ; m=masa subst. ; M=masa molara
n= 4g : 40g/moli=0,1 moli Ca
b. n=4,8g : 24g/moli=0,2moli Mg
c. n= 14,12 g : 71g/moli=0,2moli Cl2
d. 1mol Na -----------6,023.10²³atomi Na
xmoli-------------12,044.10²³atomi Na
x=12,044 .10²³ : 6,023.10²³=2 moli Na [aproximativ 2 ]
