Решите цепочки превращений:

1. NiCl2 -> Ni -> NiCl2 -> Ni(OH)2 -> NiO -> NiSO4 -> Ni(OH)1
2. MgO -> Mg -> MgCl2 -> Mg(OH)2 -> MgO -> MgSO4 -> Mg(OH)2
3. Cr -> Cr2O3 -> CrCl3 -> Cr(OH)3 -> Cr -> CrCl3
4. ZnSO4 -> Zn(OH)2 -> ZnO -><- Zn -> ZnCl2 -> Zn(OH)2
5. Pb -> PbO -> PbCl2 -> Pb(OH)2 -> PbO -. Pb -> PbCl2
6. BaCl2 -> Ba(OH)2 -> BaO -><- Ba -> BaCl2 -> BaSO4

1. NiCl_2 + 2Na = 2NaCl + NiNi + 2HCl = NiCl_2 + H_2NiCl_2 + 2KOH = 2KCl + Ni(OH)_2Ni(OH)_2 =^t NiO + H_2ONiO + H_2SO_4 = NiSO_4 + H_2ONiSO_4 + Mg(OH)_2 = Ni(OH)_2 + MgSO_42. MgO + H_2 = Mg + H_2OMg + 2HCl = MgCl_2 + H_2MgCl_2 + Pb(OH)_2 = Mg(OH)_2 + PbCl_2Mg(OH)_2 =^t MgO + H_2OMgO + H_2SO_4 = MgSO_4 + H_2OMgSO_4 + Ba(OH)_2 = BaSO_4 + Mg(OH)_23. 4Cr + 3O_2 = 2Cr_2O_3Cr_2O_3 + 6HCl = 2CrCl_3 + 3H_2OCrCl_3 + 3KOH = Cr(OH)_3 + 3KCl-2Cr + 6HCl = 2CrCl_3 + 3H_24.ZnSO_4 + 2KOH = Zn(OH)_2 + K_2SO_4Zn(OH)_2 =^t ZnO + H_2OZnO + H_2 = Zn + H_2O2Zn + O_2 = 2ZnOZn + 2HCl = ZnCl_2 + H_2ZnCl_2 + 2NaOH = 2NaCl + Zn(OH)_25. 2Pb + O_2 = 2PbOPbO + 2HCl = PbCl_2 + H_2OPbCl_2 + 2NaOH = 2NaCl + Pb(OH)_2Pb(OH)_2 =^t PbO + H_2OPb + 2HCl = PbCl_2 + H_26. BaCl_2 + 2KOH = KCl + 2Ba(OH)_2Ba(OH)_2 =^t BaO + H_2OBaO + H_2 = Ba + H_2O2Ba + O_2 = 2BaOBa + 2HCl = BaCl_2 + H_2BaCl_2 + H_2SO_4 = 2HCl + BaSO_4