a) $ZnO + 2HCl \to ZnCl_2 + H_2O$
Theo PTHH : $n_{ZnCl_2} = n_{ZnO} = \dfrac{32,4}{81} = 0,4(mol)$
$m_{ZnCl_2} = 0,4.136 = 54,4(gam)$
b) $n_{HCl} = 2n_{ZnO} = 0,8(mol)$
$m_{dd\ HCl} = \dfrac{0,8.36,5}{5\%} = 584(gam)$
c) $V_{dd\ HCl} = \dfrac{584}{1,22} = 478,7(ml)$