Question

State the reaction occurring at the anode during electrolysis of :
Dilute sulphuric acid using a platinum anode.

Answer 1

The process of dissolving ionic compounds into their constituent components by delivering a direct electric current through the complex in a fluid form is known as electrolysis.

At the cathode, cations are reduced, whereas anions are oxidised.

An electrolyte, electrodes, and some type of external power source are necessary for conducting electrolysis.

Step1 : Dissociation of sulphuric acid

${\mathrm{H}}_2{\mathrm{SO}}_4\to 2{\mathrm{H}}^{+}\left(\mathrm{aq}\right)+{\mathrm{SO}}_4^{-2}\left(\mathrm{aq}\right)$

Step2 : Dissociation of water

• A negative electrode is referred to as a cathode.
• Protons are drawn to it. Protons are discharged at the cathode, resulting in hydrogen gas.

${\mathrm{H}}_2\mathrm{O}\to {\mathrm{H}}^{+}\left(\mathrm{aq}\right)+{\mathrm{OH}}^{-}\left(\mathrm{aq}\right)$

At cathode $\to$$2{\mathrm{H}}^{+}\left(\mathrm{aq}\right)+2{\mathrm{e}}^{-}\to {\mathrm{H}}_2(\mathrm{g})$

At anode $\to$$4{\mathrm{OH}}^{-}\to 2{\mathrm{H}}_2{\mathrm{O}}^{+}\left(\mathrm{l}\right)+{\mathrm{O}}_2(\mathrm{g})+4{\mathrm{e}}^{-}$

$2{\mathrm{H}}^{+}\left(aq\right)+2{\mathrm{e}}^{-}\to {\mathrm{H}}_2\left(g\right)$

At the anode, oxygen gas will free before sulphur dioxide gas.