hydrogen electrode

chemistry

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June 29, 2026

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A hydrogen electrode is a standard electrode used in chemistry. It typically consists of platinum black on platinum, with hydrogen gas bubbled over it. This electrode is assigned a potential of zero, serving as a reference point to measure other electrode potentials.1

In fuel cells, hydrogen can be used as a fuel, reacting at one electrode while oxygen reacts at the other to generate electrical energy.2

The hydrogen electrode is crucial for establishing the electromotive series. This series lists chemical species by their tendency to gain or lose electrons, with all potentials measured against the hydrogen electrode's zero potential. The standard condition involves a hydrogen ion concentration of one mole per liter in equilibrium with hydrogen gas at one atmosphere pressure.3

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acid–base reaction
Dissociation constants in aqueous solution
For example, a hydrogen electrode (or more commonly a glass electrode, which responds in the same way) together with a reference electrode, commonly the calomel electrode, serves to measure the actual hydrogen ion concentration, or the pH, of the solution. If E is the electromotive force (in volts)…
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For example, a hydrogen electrode (or more commonly a glass electrode, which responds in the same way) together with a reference electrode, commonly the calomel electrode, serves to measure the actual hydrogen ion concentration, or the pH, of the solution. If E is the electromotive force (in volts)…
Read More

electromotive series
…measured with reference to the hydrogen electrode, which is taken as a standard and arbitrarily assigned the voltage of zero. At the hydrogen electrode, an aqueous solution containing hydrogen in its oxidized form (the hydrogen ion, H⁺) at a concentration of one mole per litre is maintained at 25° C…
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…measured with reference to the hydrogen electrode, which is taken as a standard and arbitrarily assigned the voltage of zero. At the hydrogen electrode, an aqueous solution containing hydrogen in its oxidized form (the hydrogen ion, H⁺) at a concentration of one mole per litre is maintained at 25° C…
Read More