avem formula generala n=m/M unde n=nr de moli, m=masa si M=masa molara
n=m/M
M indice H2S= 2*A indice H+ A indice S, unde A=masa atomica(se gaseste in tabelul periodic)
M indice H2S= 2*1+ 1*32=> M indice H2S=34 g/mol
n=m/M=> 3=m/34=> m=3*34=102g H2S
Sper ca te am ajutat!
