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KCET2026ChemistryThermodynamics (C)

Which of the following is a correct statement for a thermodynamic system?

Options

  1. AThe internal energy changes in all processes
  2. BInternal energy and entropy are state functions
  3. CWork is a state function
  4. DThe work done in an adiabatic process is always zero

Correct answer

B. Internal energy and entropy are state functions

Step-by-step solution

Internal energy ( U ) and entropy ( S ) depend only on the initial and final states of the system and are independent of the path followed. Therefore, they are state functions. Internal energy does not change in an isothermal process for an ideal gas or in a cyclic process, so it does not change in all processes. Work and heat are path functions, not state functions. In an adiabatic process, the heat exchange is zero ( q = 0 ), but the work done is not necessarily zero since U = w . Thus, the only correct statement

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