formula chimica Mg(NO3)2
masa molara M= (24gMg + 2x14gN+6x16gO)/mol= 148g/mol
148g azotat contine.......96gO
X...............................................4,8g
x= 4,8x148/96 gO=.....................calculeaza !!!!!
sau 1mol azotat. contine........96gO
X...........................................4,8g
CALCULEAZA X,moli azotat !!!!