1mol....................................1moll
Ca+H2SO4---> CaSO4+ H2
40g......................................22,4l
20g.....................................V=11,2l
Zn +H2SO4--> ZnSO4 + H2
65g....................................22,4l
m=.....................................11,2l
m=32,5g====================> masa unui echivalent de Zn este 32,5g