Răspuns:
MCa=40g/mol
n=m/M=4/40=0,1moli Ca
b) MMg=24g/mol
n=m/M=4,8/24=0,2moli Mg
c) MCl=35,5g/mol
n=m/M=14,2/35,5=0,4moli Cl
d)
MNa=23g/mol
1 mol -------------- 6,022×10²³ atomi Na
x moli ------------- 1,2044×10²⁴ atomi Na
x= 6,022×10²³/ 1,2044×10²⁴ = 6,022/1,2044×10=6,022/12,044= 1/2 = 0,5 moli Na
Explicație: