During the reaction of permanganate with thiosulphate, the change in oxidation of manganese occurs by value of 3. Identify which of the below medium will favour the reaction
The reaction between permanganate (\(\text{MnO}_4^-\)) ions and thiosulphate (\(\text{S}_2\text{O}_3^{2-}\)) involves a change in the oxidation state of manganese. During the reaction, manganese in permanganate is reduced, typically involving a change in its oxidation state by a value of 3.
Let's analyze the given options to identify which medium will favor the reaction.
The permanganate ion (\(\text{MnO}_4^-\)) can be reduced in different ways based on the pH of the medium:
In acidic medium: \(\text{MnO}_4^- \rightarrow \text{Mn}^{2+}\), a change of 5 in oxidation state.
In neutral medium: \(\text{MnO}_4^- \rightarrow \text{MnO}_2\), a change of 3 in oxidation state.
In alkaline medium: \(\text{MnO}_4^- \rightarrow \text{MnO}_4^{2-}\), typically a change of 1, not applicable here.
The question specifies a change in oxidation state by 3. This indicates the reaction occurs best in a neutral medium.
Option 1: Aqueous neutral is correct as it fits the requirements of the manganese oxidation state change of 3.
Option 2: Aqueous acidic is incorrect because it corresponds to a change of 5.
Option 3: Both aqueous acidic and neutral is incorrect because, while neutral is correct, acidic doesn't match the required change.
Option 4: Both aqueous acidic and faintly alkaline is incorrect as neither matches the change of 3.
Thus, the reaction of permanganate with thiosulphate, where the oxidation state of manganese changes by 3, is best favored in an aqueous neutral medium.
