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Environmental Issues — BIOLOGY STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 ScienceBIOLOGYEnvironmental Issues5 Marks
Question
  1. Why are catalytic converters recommended for vehicles?
  2. Why should such vehicles use only unleaded petrol?
  3. Why is CNG preferred to diesel as a fuel in vehicles?
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Answer

  1. Catalytic converters are recommended in automobiles to reduce air pollution by their exhaust.
  • Catalytic converters have metals like rhodium, palladium and platinum, which convert the unburnt hydrocarbons into carbon dioxide and water, carbon monoxide into carbon dioxide and nitric oxides into nitrogen.
  1. Only unleaded petrol must be used in such vehicles as lead would inactivate the catalyst.
  2. CNG is preferred as a fuel because:
  • It burns efficiently in the vehicles and very little of it is left unburnt.
  • It cannot be adulterated.

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