Памагитис химией !!! Zn + HCl = MgO + HCl = CrO3 + HCl =
Zn + 2HCl = ZnCl2 + H2 MgO + 2HCl = MgCl2 + H2O 2CrO3 + 12HCl = 3Cl2 + 2CrCl3 + 6H2O