Electrolysis of Some Common Electrolyte

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Electrolysis of Dilute Tetraoxosulphate(IV) Acid (Acidified Water):

Water containing a small amount of acid dissolved in is called acidified water .

In the electrolysis of acidified water, dilute sulphuric acid is preferred over other mineral acids like dilute nitric or hydrochloric acid, for acidification of water. Since water is a non-electrolyte, the addition of sulphuric acid makes it a conductor of electricity.

Dilute sulphuric acid is preferred because the nitrate ions or chloride ions in dilute nitric and dilute hydrochloric acid respectively may interfere with the reactions.

The electrolytic cell used for acidified water is known as the Hoffman voltameter . The electrodes used are platinum foil. 

The ions present in the electrodes are: 

H₂ SO_4(aq) ⇌ 2H⁺ _(aq) + SO₄ ^2- _(aq)

H₂ O_(aq) ⇌ H⁺ _(aq) + OH^– _(aq)

At the cathodeA cathode is the electrode from which a conventional current leaves the electrolyte. It is the negative part of the cell where reduction takes place. More:

The only cationsCations are positively charged ions (atoms or groups of atoms that have more protons than electrons due to having lost one or more electrons). Cations are attracted to negatively charged electrodes... More present, H⁺ , migrate to the cathode. They each acquire an elctron to become hydrogen atoms.

H⁺ _(aq)