On electrolysis of dilute sulphuric acid using platinum electrodes, th...
Electrolysis of Dilute Sulphuric Acid with Platinum Electrodes
When dilute sulphuric acid (H2SO4) is electrolyzed using platinum electrodes, two separate reactions occur at the anode and cathode. Let's analyze each of these reactions in detail:
Anode Reaction:
At the anode, oxidation occurs. The possible reactions that can take place are:
1. 2H2O(l) → O2(g) + 4H+(aq) + 4e-
- In this reaction, water molecules are oxidized to form oxygen gas, protons (H+ ions), and electrons.
- This reaction represents the formation of oxygen gas at the anode.
2. 4OH-(aq) → 2H2O(l) + O2(g) + 4e-
- In this reaction, hydroxide ions (OH-) are oxidized to form water, oxygen gas, and electrons.
- This reaction also represents the formation of oxygen gas at the anode.
Cathode Reaction:
At the cathode, reduction occurs. The possible reactions that can take place are:
1. 2H+(aq) + 2e- → H2(g)
- In this reaction, protons (H+ ions) are reduced to form hydrogen gas.
- This reaction represents the formation of hydrogen gas at the cathode.
Based on the reactions mentioned above, it is clear that when dilute sulphuric acid is electrolyzed using platinum electrodes, the product obtained at the anode is oxygen gas (O2) and the product obtained at the cathode is hydrogen gas (H2). Therefore, the correct answer is option 'B' - oxygen.
It is important to note that the choice of electrodes (platinum in this case) is crucial in determining the products of electrolysis. Platinum is an inert metal that does not react with the electrolyte or the products, allowing the desired reactions to occur without interfering side reactions.