Răspuns:
1. MMgSO4=24+32+4×16=120g/mol
2.
120gMgSO4...................24gMg............32gS.........64gO
100gMgSO4....................x%Mg................y%S.............z%O
x=100×24/120= calculeaza
y=100×32/120= calculeaza
z=100×64/120= calculeaza
Explicație: