Simple Electrolytic Redox Systems Formulation based on generalized electron balance (GEB) / generalized approach to electrolytic systems (GATES).

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Redox reactions are characterized by the transfer of electrons between chemical species, (the reducing agent) undergoing oxidation (losing electrons) and (the oxidizing agent) undergoes reduction (gains electrons). The linear combination f12 = 2?f(O) – f(H) of elemental balances: f1 = f(H) for H, and f2 = f(O) for O is the basis to formulate the generalized electron balance (GEB) for electrolytic redox systems according to Approach II to GEB, realized within the generalized approach to electrolytic systems (GATES) as GATES/GEB. Together with charge balance (f0 = ChB) and K–2 elemental/core balances: f3,…,fK, the f12 completes the set of K balances needed for resolution of an electrolytic redox system, of any degree of complexity. For a nonredox system, a proper linear combination of f12 with f0, and fk = f(Yk) (Yk ≠ H, O; k=3,…,K) gives the identity, 0 = 0. Consequently, in nonredox systems, f12 is linearly dependent on f0,f3,…,fK, i.e., f12 is not the independent balance. This independency/dependency property of f12 distinguishes between redox and non-redox systems. In a redox system, a proper linear combination of f12+f0 with the balances for electron-non-active elements/cores gives the simpler form of GEB, where the species composed only of electron-non-active elements are not involved. The multipliers applied in the linear combinations are equal to the oxidation numbers for elements participating redox or non-redox system. This regularity is highly important in context of the fact that the ‘oxidation number’ was essentially a contractual concept. Within GATES/GEB, the terms: oxidation number, oxidant and reductant, stoichiometry, and equivalent mass are derivative/redundant concepts only; the roles of oxidants and reductants are not assigned a priori to individual components. All these concepts are illustrated on simple examples of redox D+T systems, with aqueous solutions of (S1) Br2, and (S2) HBrO as titrand D, and NaOH solution as titrant T.