Răspuns:
Explicație:
1. n= m : M
n= 320g : 80g/moli = 4moli Br2
2. 1mol Fe---------6,022.10²³atomi Fe
0,1 moli Fe---------------x
x= 0,1 . 6,022.10²³ = 0,6022 .10²³atomi Fe
3 . n= m : M
n= 0,2g : 40g/moli = 0,005 moli Ca
4. m= n . M
m = 2,5moli . 32g/moli = 80 g S