n Zn = 19,5/65=0,3(mol)
PTHH:Zn+2HCl->ZnCl2+H2
(mol)__0,3___0,6____0,3____0,3__
m HCl = 0,6.36,5=21,9(g)
V H2 = 0,3.22,4=6,72(l)
n CuO = 8/80=0,1(mol)
PTHH:CuO+H2-to->Cu+H2O
(mol)___0,1____________0,1___
Tỉ lệ: 0,3/1 > 0,1/1 -> H2 dư
m Cu = 0,1.64=6,4(g)