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MHT CET202520 Apr 2025Morning ShiftChemistryThermodynamics (C)Actual

Which from following process involves zero work done?

Options

  1. AIsobaric expansion of gas.
  2. BAdiabatic compression of gas.
  3. CIsothermal expansion of gas.
  4. DFree expansion of gas.

Correct answer

D. Free expansion of gas.

Step-by-step solution

The work done by a gas during expansion or compression is given by W = -P_ ext V , where P_ ext is the external pressure and V is the volume change. Isobaric expansion occurs at constant pressure with V 0 , yielding non-zero work since P_ ext 0 . Adiabatic compression involves volume decrease with no heat exchange, producing non-zero work as P_ ext 0 . Isothermal expansion maintains constant temperature with volume increase, resulting in non-zero work W = -nRT (V₂/V₁) . Free expansion occurs against zero external p

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