Chemistry - Thermodynamics - I Question with Solution | TestHub
Statement-1 : The magnitude of work done by an ideal gas in adiabatic reversible expansion from the same initial pressure and volume to the same final volume is less than that in isothermal reversible process.
Statement-2: If an ideal gas is expanded reversibly from the same initial pressure and volume to the same final volume, then the final pressure in adiabatic process is less than that in the isothermal process.
Options:
Answer:
Solution:
For reversible expansion of an ideal gas, both statements are correct.
In adiabatic expansion, temperature drops, so pressure falls faster than in isothermal process, hence final pressure is lower in adiabatic case (Statement-2 is correct).
Because pressure is lower during the path, the area under P–V curve (work done) is also smaller in adiabatic expansion compared to isothermal expansion (Statement-1 is correct).
Thus, Statement-2 correctly explains why Statement-1 is true.
So, both statements are correct and Statement-2 is the correct explanation of Statement-1.
Hence, Option (A).