OnlineCBT
Chemistry · THERMODYNAMICS
हिन्दीConsider the following statements regarding the thermodynamic expansion of an ideal gas: (A) In a free expansion of an ideal gas into vacuum under isothermal conditions, \( w = 0 \), \( q = 0 \), and \( \Delta U = 0 \). (B) The magnitude of reversible isothermal expansion work is always greater than the magnitude of irreversible expansion work against a constant external pressure between the same initial and final states. (C) For an ideal gas expanding at constant volume, work done is zero and the heat absorbed is exactly equal to the change in enthalpy \( \Delta H \). (D) A reversible process proceeds through a series of equilibrium states such that the system and surroundings are always in near equilibrium with each other. How many of the above statements are correct?
Correct answer · Option 3
Only three
Explanation
Statement (C) is incorrect because at constant volume, \( q_v = \Delta U \), not \( \Delta H \) (heat at constant pressure \( q_p = \Delta H \)). Statements (A), (B), and (D) are correct; thus exactly three statements are correct.
