UPSC Prelims 2024·GS1·science-and-technology·science and technology

Which one of the following is the exhaust pipe emission from Fuel Cell Electric Vehicles, powered by hydrogen ?

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Last updated 23 May 2026, 3:31 pm IST
  1. AHydrogen peroxide
  2. BHydronium
  3. COxygen
  4. DWater vapourCorrect

Explanation

Fuel Cell Electric Vehicles (FCEVs) powered by hydrogen generate electricity through an electrochemical reaction between hydrogen (H₂) and oxygen (O₂) from the air. The chemical reaction that occurs in the fuel cell is: 2H₂ (hydrogen) + O₂ (oxygen) → 2H₂O (water) + electricity + heat The primary exhaust emission from the tailpipe of a hydrogen FCEV is **water vapour**. This makes FCEVs zero-emission vehicles at the point of use, as they only produce water. * **Hydrogen peroxide (H₂O₂):** A strong oxidizer, not a primary exhaust product. * **Hydronium (H₃O⁺):** An ion found in acidic solutions, not an exhaust gas. * **Oxygen (O₂):** A reactant in the fuel cell, taken from the air, not an emission. Therefore, water vapour is the correct answer.
science-and-technology: Which one of the following is the exhaust pipe emission from Fuel Cell Electric Vehicles, powered by hydrogen ?

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