Thermodynamics and Thermochemistry 1 Question 39
42. An ideal gas in thermally insulated vessel at internal pressure , volume and absolute temperature expands irreversibly against zero external pressure, as shown in the diagram. The final internal pressure, volume and absolute temperature of the gas are and , respectively. For this expansion
(a)
(b)
(c)
(d)
(2014 Adv.)
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Solution:
- PLAN This problem includes concept of isothermal adiabatic irreversible expansion.
Process is adiabatic because of the use of thermal insolution therefore,
Internal energy can be written as
The change in internal energy of an ideal gas depends only on temperature and change in internal energy
and
(d)
Hence, only (a), (b) and (c) are correct choices.