K2Cr2O7 + HCl -> CrCl3 + Cl2 + H2O + KCl
Cr2O7(2-) + 6е + 14Н(+) = 2Cr(3+) + 7H2O |2 2Cl(-) - 2е = Cl2 |6
K2Cr2O7 + 14HCl -> 2CrCl3 + 3Cl2 + 7H2O + 2KCl