Explanation:

Electrolysis of dilute H2SO4 using platinum electrodes results in the formation of oxygen gas at the anode and hydrogen gas at the cathode. This can be explained by the following factors:

1. Electrolysis Process:

Electrolysis is the process of passing an electric current through a solution or a molten compound to decompose it into its constituent elements. In the case of dilute H2SO4, when an electric current is passed through the solution, it decomposes into hydrogen ions (H+) and sulfate ions (SO4 2-).

2. Electrode Reactions:

During the electrolysis process, the platinum electrodes act as catalysts for the electrode reactions. The electrode reactions that occur at the anode and cathode are as follows:

At the anode: 2H+ (aq) → H2(g) + O2(g)

At the cathode: 2H+ (aq) + 2e- → H2(g)

At the anode, the hydrogen ions (H+) lose electrons and combine with each other to form hydrogen gas (H2) and oxygen gas (O2). However, due to the high overpotential of the platinum electrode for hydrogen evolution, the oxygen gas is the major product. At the cathode, the hydrogen ions (H+) gain electrons and form hydrogen gas (H2).

3. Faraday's Law:

The amount of gas produced during electrolysis is directly proportional to the amount of charge passed through the electrolyte. This is known as Faraday's law of electrolysis. The volume of gas produced can be calculated by using the following equation:

Volume of gas = (Current × Time × Molar volume of gas) / (2 × Faraday's constant)

In conclusion, during the electrolysis of dilute H2SO4 using platinum electrodes, oxygen gas is formed at the anode due to the high overpotential of the platinum electrode for hydrogen evolution. This can be explained by the electrode reactions that occur at the anode and cathode, as well as Faraday's law of electrolysis.

In aqueous solution, dilute sulphuric acid dissociates to form protons and sulphate ions. Also, the autoionisation of water gives protons and hydroxide ions. Thus, the dilute aqueous sulphuric acid solution contains protons, hydroxide ions and sulphate ions.
Anode is a positive electrode. It attracts hydroxide ions and sulphate ions. At anode, hydroxide ions get discharged (in preference to sulphate ions) to form oxygen gas.
The electrode potential for the above reaction is 0.0 V.
The electrode potential for the discharge of sulphate ions is 1.23 V

When hydroxide ions are discharged, oxygen gas is liberated at anode. However if sulphate ions are discharged, sulphur dioxide gas is liberated. Since the value of the electrode potential for the discharge of hydroxide ions is less than that of sulphate ions, the hydroxide ions will get discharged preferentially at anode. Due to this, oxygen gas will liberate in preference to sulphur dioxide gas at anode.

During the electrolysis of dilute aqueous sulphuric acid, using platinum electrodes, oxygen gas is liberated at anode.