Putem calcula masa moleculara la fiecare si apoi exprimam procentul de sulf din fiecare compus.
M1=2*ACu+AS = 2*64+32=128+32=160 g/mol
160 g compus ... 32 g S
100 ... p1=20%
M2=ACu+AS = 64+32=96 g/mol
96 g compus ... 32 g S
100 ... p2=33.33%
M3=ACu+AS+4*AO=64+32+4*16=96+64=160 g/mol
160g compus ......32 g S => 20% (la fel ca la primul compus)
M4=AS+2*AO=32+2*16=64 g/mol
64g compus .... 32g S
100 .... p4=50%
=>Compusul cel mai bogat in sulf e SO2.