Răspuns:
a) MCa=40g/mol
n=m/M=4/40=0,1moli
b) MMg=24g/mol
n=m/M=4,8/24=0,2moli
c) MCl2=2×35,5=71g/mol
n=m/M=14,2/71=0,2moli
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
e) MHg=201g/mol
n=m/M=8/201=0.039moli
Explicație: