Question

Catalytic converters fitted in vehicles are used for\(\underline{\hspace{6cm}}\).

• A. oxidation of NO\(_x\), CO and hydrocarbons.
• B. oxidation of CO and reduction of NO\(_x\).
• C. reduction of CO\(_2\) and oxidation of NO.
• D. oxidation of CO, and reduction of NO\(_2\) and volatile organic carbons.

Hint:

Remember the mnemonic "NOx is reduced, CO/HC are oxidized". The goal is to turn harmful gases (NOx, CO, HC) into harmless ones (N\(_2\), CO\(_2\), H\(_2\)O).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
A catalytic converter is an exhaust emission control device that converts toxic gases and pollutants in exhaust gas from an internal combustion engine into less-toxic pollutants by catalyzing a redox reaction.

Step 3: Detailed Explanation:
Modern three-way catalytic converters perform three simultaneous tasks:
1. Reduction of nitrogen oxides (NO\(_x\)) to nitrogen gas (N\(_2\)): This is a reduction reaction. (e.g., \(2NO\rightarrow N_2 + O_2\)) 2. Oxidation of carbon monoxide (CO) to carbon dioxide (CO\(_2\)): This is an oxidation reaction. (e.g., \(2CO + O_2\rightarrow 2CO_2\)) 3. Oxidation of unburnt hydrocarbons (HC) to carbon dioxide (CO\(_2\)) and water (H\(_2\)O): This is also an oxidation reaction.
Therefore, the catalytic converter's main functions are the oxidation of CO and hydrocarbons, and the reduction of NO\(_x\).

Step 4: Final Answer:
Catalytic converters are used for the oxidation of CO (and hydrocarbons) and the reduction of NO\(_2\).