n1 moli Cu
n2 moli Zn + 2HCl = ZnCl2 + H2↑ nH2 = nZn = 22,4/22,4 = 1mol
⇒ mZn = 1·65 = 65g ⇒ mCu = 35g
%Zn = 65% %Cu = 35%
solutia initiala de HCl : msi = 300g ci = 36,5% ⇒ mdi = 109,5g niHCl = 3 moli
reactioneaza : 1mol Zn + 2moli HCl
nHCl exces = 1mol
KOH + HCl = KCl + H2O
nKOH = nHCl = 1mol (m = 56g) ms = 56·100/20 = 280g
3Cu + 8HNO3 = 3Cu(NO3)2 + 2NO + 4H2O
nNO = 2/3·nCu = 2/3 ·35/64 = 35/96 moli m = 35/96 ·30 10,9375 g