The product obtained at anode when \(50 \% \mathrm{H}_{2} \mathrm{SO}_{4}\) aqueous solution is electrolysed using platinum electrodes is (a) \(\mathrm{H}_{2}\) (b) \(\mathrm{O}_{2}\) (c) \(\mathrm{H}_{2} \mathrm{SO}_{3}\) (d) \(\mathrm{H}_{2} \mathrm{~S}_{2} \mathrm{O}_{8}\)

Chemical reactions are the processes by which substances interact to form new products. This involves breaking chemical bonds in the reactants and forming new bonds to create different substances. Each chemical reaction is governed by the laws of conservation of mass and energy, meaning that total mass and energy remain constant before and after the reaction. In most reactions, the reactants undergo changes in their electronic structure, leading to the rearrangement of atoms.

Different types of chemical reactions include synthesis, decomposition, single replacement, and double replacement reactions. Electrolysis, the process under discussion, is a type of decomposition reaction where an electric current drives the breakdown of a compound, typically in a solution or molten state. By passing electricity through an electrolyte like sulfuric acid, we can decompose it into hydrogen and oxygen gases, along with various other possible products depending on the specific conditions of the electrolysis.

In electrolysis, the anode is the electrode connected to the positive terminal of the power source, and it's where oxidation occurs. Oxidation is the loss of electrons by a molecule, atom, or ion. The oxidation reaction at the anode is crucial because it determines the substances produced at this electrode during electrolysis.

For the sulfuric acid electrolysis example, the anode oxidation reaction involves the conversion of water molecules (H₂O) into oxygen gas (O₂) and protons (H⁺), which are then released into the solution. This process also produces electrons (e-), which flow through the circuit to the cathode. It's important to note that while sulfuric acid itself is a potential oxidizing agent, in dilute solutions, and especially at the concentration of 50% mentioned in the exercise, water is preferentially oxidized over the sulfate (SO₄^2-) ions.

Electrolysis of aqueous solutions involves passing an electric current through a liquid that contains ions, causing chemical changes at the electrodes. In the context of sulfuric acid (H₂SO₄) electrolysis, the solution also contains a large amount of water, which also plays a significant role. Water acts not just as a solvent but also as a reactant during electrolysis.

In the electrolysis of aqueous sulfuric acid, water molecules are more likely to be involved in the reactions at both electrodes. As mentioned earlier, at the anode, water is oxidized to produce oxygen gas and hydrogen ions. At the cathode in acidic solutions like sulfuric acid, hydrogen ions (H⁺) are typically reduced to hydrogen gas (H₂). This is why, despite sulfuric acid being the electrolyte, water is usually the species that gets electrolyzed, particularly in dilute solutions.