JEE Chemistry 2024 Question with Solution

Given: The standard reduction potentials are $E^\circ(\text{ClO}_3^-) = 1.19 \, \text{V}$, $E^\circ(\text{IO}_3^-) = 1.65 \, \text{V}$, and $E^\circ(\text{BrO}_3^-) = 1.74 \, \text{V}$.

Find: The correct order of oxidising power.

Principle: A species with a higher standard reduction potential has a greater tendency to get reduced and therefore acts as a stronger oxidising agent.

Comparing the given values:

$$1.74 \, \text{V} > 1.65 \, \text{V} > 1.19 \, \text{V}$$

So, the oxidising power follows the same order:

$$\text{BrO}_3^- > \text{IO}_3^- > \text{ClO}_3^-$$

Therefore, the correct option is B.

Note: The solution refers to $\text{BrO}_4^-$, $\text{IO}_4^-$, and $\text{ClO}_4^-$, which is inconsistent with the question statement and options. However, the answer logic based on the given $E^\circ$ values remains the same, so the correct order is still $\text{BrO}_3^- > \text{IO}_3^- > \text{ClO}_3^-$.