Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
MHT CET202523 Apr 2025Morning ShiftChemistryThermodynamics (C)Actual

Calculate work done in isothermal reversible expansion of 1 mole ideal gas from initial pressure 10 bar to final pressure 1 bar at 300 K ( R =8.314 ~J ~K ⁻¹ ~mol ⁻¹ )

Options

  1. A-2.87 ~kJ
  2. B-8 60 ~kJ
  3. C-5.74 ~kJ
  4. D-11.49 ~kJ

Correct answer

C. -5.74 ~kJ

Step-by-step solution

The work done by an ideal gas during an isothermal reversible expansion is given by W = -nRT ( V₂ V₁ ) . Since pressure and volume vary inversely for an ideal gas at constant temperature, V₂ V₁ = P₁ P₂ , yielding W = -nRT ( P₁ P₂ ) . Substituting the given values n = 1 mol, R = 8.314 J K ⁻¹ mol ⁻¹ , T = 300 K, P₁ = 10 bar, and P₂ = 1 bar: W = -(1)(8.314)(300) ( 10 1 ) Calculating stepwise: 8.314 300 = 2494.2 (10) 2.303 W = -2494.2 2.303 = -5744.1426 J = -5.744 kJ Among the options provided, -5.74 kJ corresponds to

Practice Thermodynamics (C) on Quantrex Academy →

More from Thermodynamics (C)

Identify the INCORRECT statement 2026The standard enthalpies of formation of CH₄ (g), CO₂ (g) and H₂ O(l) are -74.8 kJ mol ⁻¹ , -393.5 kJ mol ⁻¹ and -285.8 kJ mol ⁻¹ respectively. Then the enthalpy change for the give 2026For an ideal gas undergoing an isothermal change, there is 2026Ozone is formed by the reaction O _ 2(g) + O _ (g) O _ 3(g) , H = -107.2 kJ . Given O=O bond energy is 498.0 kJ mol ⁻¹ , the average bond energy of ozone is: 2026H and S for a reaction are 35.5 kJ mol ⁻¹ and 83.6 J K ⁻¹ respectively. Assuming that H and S do not vary with temperature, the reaction is spontaneous when: 2026The heat of combustion of carbon to CO ₂ is -393.5 kJ mol ⁻¹ . The heat released on the formation of 35.2 g of CO ₂ by combustion of C is: 20265 moles of a gas is allowed to pass through a series of changes as shown in the graph, in a cyclic process. The processes C A , B C and A B respectively are 20251 mole of an ideal gas is allowed to expand isothermally and reversibly from 1 L to 5 L at 300 K. The change in enthalpy (in kJ ) is ( R =8.3 ~J ~K ⁻¹ ~mol ⁻¹ ) 2025 Full Thermodynamics (C) list All MHT CET PYQs