Ca(NO3)2
raport atomic Ca:N:O=1:2:6
raport de masa: Ca:N:O=40:28:96=20:14:48
MCa(NO3)2=ACa+2×AN+6×AO=40+2×14+6×16=164g
164gCa(NO3)2....40gCa...28gN...96gO
100gCa(NO3)2........xgCa........ygN.......zgO
x=100×40/164=calculeaza
y=100×28/164=calculeaza
z=100×96/164=calculeaza
.