calculez moli Mg, stiind M,Mg= 24g/mol
niu=m/M=240g/24g/mol= 10mol Mg
calculez moli si masa O2 din ecuatia chimica
2mol........1mol
2Mg + O2----> 2MgO
10mol......x= 5molO2
m= niuxM= 5molx32g/mol= ..........................calculeaza !!!!pentru ca M,O2=32g/mol
