Question

Which of the following is not a state function?

• A. Work
• B. Entropy
• C. Enthalpy
• D. Internal energy

Answer 1

The correct option is A

Work

Explanation for correct option

(A) Work

State function

• “Variables like pressure, volume, and temperature are called state variables or state functions because their values depend only on the state of the system and not on how it is reached.”

Path function

• It depends on the path between the initial and final state is known as the path function.
• Work and heat are examples of path functions.

Hence, work is a path function, not a state function.

Explanation for incorrect option

• Internal energy, entropy, and enthalpy are all state functions, which means that the state determines its values rather than the path is taken.
• Hence, options (B), (C), and (D) are incorrect.

Hence, option (A) is the correct option. Work is not a state function.