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MHT CET202526 Apr 2025Evening ShiftChemistryThermodynamics (C)Actual

Calculate the work done if 1 mole of certain gas compressed isothermally and reversibly at 300 K from initial pressure x bar to final pressure 2 x bar [ R =8 314 ~J ~K ⁻¹ ~mol ⁻¹ ]

Options

  1. A1.729 kJ
  2. B0.865 kJ
  3. C2.593 kJ
  4. D3.458 kJ

Correct answer

A. 1.729 kJ

Step-by-step solution

Work during isothermal reversible compression of an ideal gas: The work done is given by W = - nRT ( P ₁ P ₂ ) . Substituting the given values: n = 1 mol , T = 300 K , R = 8.314 J K ⁻¹ mol ⁻¹ , and P ₁ P ₂ = x 2x = 1 2 . W = -(1) (8.314) (300) ( 1 2 ) W = -2494.2 ( 1 2 ) Since ( 1 2 ) = - (2) -0.6931 : W = -2494.2 (-0.6931) = 1728.86 J Converting to kilojoules: W = 1.72886 kJ 1.729 kJ The positive value indicates work is done on the system during compression, and this matches option A. A

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