A,Mg= 24g/mol A,O2=32g/mol
ecuatia reactiei este:
Mg + 1/2 O2--------> MgO
24g...............................(24+16)g
120g..............................m= 200g
pentru a calcula numarul de moli MgO,din m obtinut, imparti m la M= 40g/mol
n(niu)= m/M------> N=200g/40g/mol=.......................calculeaza !!!!