a) PTHH: Zn + 2HCl → ZnCl2 + H2↑
b) nZn = \(\dfrac{m_{Zn}}{M_{Zn}}\) = \(\dfrac{3,5}{65}\approx\) 0,054 (mol)
nH\(_2\) = nZn = 0,054 (mol)
VH\(_2\) = 0,54 . 22,4 = 1,2096 (l)
nZnCl\(_2\) = nZn = 0,054 (mol)
mZnCl\(_2\) = 0,054 . 136 = 7,344 (g)
c) PTHH: H2 + CuO → H2O + Cu
nCu = nH\(_2\) = 0,054 (mol)
mCu = 0,054 . 64 = 3,456 (g)