Question

If a reaction occurs in following two steps

i. \(2 \mathrm{ClO}^{-} \longrightarrow \mathrm{ClO}_2^{-}\)

ii. \(\mathrm{ClO}_2^{-}+\mathrm{ClO}^{-} \longrightarrow \mathrm{ClO}_3^{-}+\mathrm{Cl}^{-}\)

Find the reaction intermediate.

• A. \(\mathrm{ClO}^{-}\)
• B. \(\mathrm{ClO}_{3}^{-}\)
• C. \(\mathrm{Cl}^{-}\)
• D. \(\mathrm{ClO}_{2}^{-}\)

Hint:

An intermediate is formed in one step and consumed in a later step.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept
A reaction intermediate is produced in an early step and used up in a later step, so it does not appear in the overall reaction.

Step 2: Step Analysis
Step (i) forms \(\text{ClO}_2^-\) from \(2\text{ClO}^-\). Step (ii) uses \(\text{ClO}_2^-\) with another \(\text{ClO}^-\).

Step 3: Identify
\(\text{ClO}_2^-\) is formed and then consumed, so it is the intermediate. \(\text{ClO}^-\) is a reactant, and \(\text{ClO}_3^-\) and \(\text{Cl}^-\) are final products.

Final Answer:
The intermediate is chlorite ion. \[ \boxed{\text{(D) }\text{ClO}_2^{-}} \]