Practical problems related to Hydrogen Electrode :

Even by the hydrogen electrode is first and basic reference electrode developed, now-a-days, several other subsidiary standard electrodes, that could be simply prepared and permanently set up, are available for practical use and are preferred because of easiness to set up in comparison along with hydrogen electrode, that is more complicated and need rigorous experimental conditions.

The Hydrogen electrode is inconvenient for use in practical routine laboratory experiments since it has got the following practical problems.

1. It requires a large gas cylinder.

2. Hydrogen and air mixture is highly explosive.

3. Catalyst is easily poisoned.

Hence for routine laboratory use some other reference electrodes are commonly employed for measuring potentials of other half-cells. The potentials of these reference electrodes have been measured against standard hydrogen electrode (SHE) and in potentiometry, the potential of any system is expressed as if it is measured with reference to the potential of standard hydrogen electrode (SHE)

The simple and common reference electrodes widely used are calomel electrode and silver-silver chloride electrode. Those two are preferred since of their simple fabrication and maintain a constant and reproducible potential.