Question

Select the correct option(s) for the following statements
1. \(Cl_2O\) and \(ClO_2\) are used as bleaching agents
2. \(OCl^-\) salts are used as detergents
3. \(OCl^-\) disproportionates in alkaline medium
4. \(BrO_3^-\) is oxidized in acidic medium
Which of the following combination is correct?

• A. 1, 2, 3 correct
• B. 2, 3, 4 correct
• C. 1, 2, 4 correct
• D. 1, 3, 4 correct
• E. All are correct

Hint:

Most halogen oxoanions in high oxidation states (like \(ClO_3^-, BrO_3^-\)) are naturally strong oxidizers; they "want" to take electrons and be reduced to more stable halides.

Answer 1

The Correct Option is A

Concept: This question covers the industrial applications and chemical properties of halogen oxides and oxoanions.

Step 1: Evaluate statements 1 and 2.

• Statement 1: Chlorine oxides like \(ClO_2\) are powerful oxidizing agents used extensively as bleaching agents for wood pulp and textiles. (True)
• Statement 2: Hypochlorite (\(OCl^-\)) salts, such as \(NaOCl\), are the active ingredients in liquid bleaches and are often found in cleaning/detergent formulations for disinfection. (True)

Step 2: Evaluate statement 3.
In alkaline solutions, the hypochlorite ion (\(OCl^-\)) is unstable at higher temperatures and undergoes disproportionation to form chloride and chlorate: \[ 3OCl^- \rightarrow 2Cl^- + ClO_3^- \] (True).

Step 3: Evaluate statement 4.
Bromate (\(BrO_3^-\)) is already in a high oxidation state (+5). In acidic medium, it usually acts as a strong oxidizing agent, meaning it gets reduced (to \(Br_2\) or \(Br^-\)), not oxidized. (False).