Irreversible reaction

Anodic oxygen from back-migrated hydroxide (net water electrolysis)

Direction: Irreversible
Processes: 2
Stated as: Stoichiometry only
Heat of reaction: ΔH = 571,660 kJ/kmol (2 processes)
Element balance: Checked: balances in all 2 processes

As the processes state itStoichiometry, conversions, heats of reaction and catalyst windows are taken from each process's files with their provenance. The build checks only that each process's equation balances in every element, from the process's own component formulas; it does not check the numbers. A process's design maturity applies to them.

Species

Species	Name	CAS	Role	Coefficient
H₂O	Water	7732-18-5	reactant	-2
H₂	Hydrogen	1333-74-0	product	2
O₂	Oxygen	7782-44-7	product	1

Also stated as each of 2 H2 + O2 ⇌ 2 H2O, 2 H2 + O2 → 2 H2O (reversible and irreversible statements are kept apart).

In the processes

Chlor-alkali by membrane-cell electrolysis (100 kt/a Cl2, 50 wt-% caustic soda, hydrogen)Concept · not reviewed
WATER_SPLIT · Anodic oxygen from back-migrated hydroxide (net water electrolysis)2 H2O → 2 H2 + O2
Element balance
Balances in every element
Heat of reaction
ΔH = 571,660 kJ/kmol at 298.15 K, as written (given: CODATA Key Values (Cox et al. 1989): -2 x (-285.830) kJ/mol, H2O liquid)
Potassium permanganate from MnO2 ore by KOH roasting and electrolysis (1250 kg/h, concept)Concept · not reviewed
WATER_SPLIT · Anodic oxygen evolution (current-efficiency loss; net water electrolysis)2 H2O → 2 H2 + O2
Phase
liquid
Element balance
Balances in every element
Heat of reaction
ΔH = 571,660 kJ/kmol at 298.15 K, as written (assumed: ASSUMED until the table is re-read (review 2026-10-28-pfd-lci-review#10): CODATA Key Values (Cox et al. 1989), recalled, -2 x (-285.830) kJ/mol, H2O liquid (SRC-8))

Sources

What the processes cite for this reaction, each source once: for the reaction itself, its conversion, its heat of reaction or its catalyst. As the processes write them; DOIs, US patent numbers and web addresses are linked.

CODATA Key Values (Cox et al. 1989): -2 x (-285.830) kJ/mol, H2O liquid
For the heat of reaction · cited by Chlor-alkali by membrane-cell electrolysis (100 kt/a Cl2, 50 wt-% caustic soda, hydrogen)
ASSUMED until the table is re-read (review 2026-10-28-pfd-lci-review#10): CODATA Key Values (Cox et al. 1989), recalled, -2 x (-285.830) kJ/mol, H2O liquid (SRC-8)
For the heat of reaction · cited by Potassium permanganate from MnO2 ore by KOH roasting and electrolysis (1250 kg/h, concept)