Notez "*" înmulțire si "/" împărțire
2HCl + Zn ->ZnCl2 + H2
2moli HCl..........1mol Zn
x moli HCl....0.2 moli Zn
x=0.2*2/1=0.4 moli HCl
nr moli=md/M => md=nr moli*M =0.4*36.5=14.6g
Cp=md/ms*100 =>ms=md*100/Cp=14.6*100/20=73g solutie
MHCl=1+35.5=36.5g/mol