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  9. Q66

OPSC OCS 2025 · Question 66 of 84

Which one of the following processes involves a decrease in entropy? (2025)

Current Affairs

  1. ABurning of coal in air
  2. BFormation of NH3 from H2 and N2Correct
  3. CEvaporation of water
  4. DMelting of ice

Answer: B. Formation of NH3 from H2 and N2

Explanation

Entropy is a thermodynamic quantity that represents the degree of disorder or randomness in a system. A decrease in entropy implies an increase in order within the system.

Source: OPSC OCS Prelims 2025 GS Paper-I (Set D); answers per Apti Plus unofficial key

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