Cu+HCl=nu reactioneaza
Zn+2HCl=ZnCl₂+H₂
gazul=H₂
1mol........................22.4l
x moli......................6.72
x=6.72*1/22.4=0.3moli H₂
1mol..........................2g H₂
0.3moli.......................y
y=2*0.3/1=0.6g H₂
z=masa de Zn reactionata
z=0.6*65/2=19.5g Zn
⇒masa de cupru=19.5g Cu
⇒aliajul contine 50% Cu si 50%Zn