Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
MHT CET202619 April 2026Morning ShiftChemistryThermodynamics (C)Actual

An ideal gas expands from initial volume 5 dm ^3 to 15 dm ^3 against a constant external pressure of 2 atm. What is the work done by the gas ?

Options

  1. A-1202.6 J
  2. B-2026.4 J
  3. C-1101.32 J
  4. D-1013.2 J

Correct answer

B. -2026.4 J

Step-by-step solution

The work done by a gas during expansion against a constant external pressure is given by the formula: W = -P_ ext V Given: P_ ext = 2 atm V_i = 5 dm ^3 = 5 L V_f = 15 dm ^3 = 15 L Change in volume: V = V_f - V_i = 15 - 5 = 10 L Substituting the values into the formula: W = -2 atm 10 L = -20 L atm To convert the work done into Joules, use the conversion factor 1 L atm = 101.32 J : W = -20 101.32 J = -2026.4 J Answer: -2026.4 J

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