Question

Which one of the following statements is false?
a) Work is a state function.
b) Temperature is a state function.
c) Change in the state is completely defined when the initial and final states are specified.
d) Work appears at the boundary of the system.

Answer 1

Hint: A state function is a property whose value does not depend on the path taken to reach that specific value. On the other hand, path function is a property whose values depend on the path of transition of a system from the initial state to the final state.

Complete step by step answer:
1. Work appears only as change in the state at the boundary of the system. It does depend on the path taken in going from state one to state two. So, work done is a path function. Hence, the statement is false.
2. Temperature measures a property of a state of a system irrespective of how it got there. That means temperature is a state function. Temperature is a state function that means No matter how many times we heat, cool, expand, compress, or otherwise change the system, the net change in the temperature only depends on the initial and final states of the system. So, the second statement is true.
3. When all the parameters like Pressure(V), Volume(V) and Temperature(T) are given for both the initial and the final states we can easily define the change in the state, that means the third statement is also true.
4. We have already discussed in the first statement that Work appears only as change in the state at the boundary of the system. It is a path function and It can be defined as any quantity of energy that flows across the boundary between the system and surroundings. So, the fourth option is also true.

Therefore, from the above statements we can conclude that the only option false here is (a).

Note: The other state functions are:
a) Enthalpy: It is defined in terms of state functions for example U, P, and V are all state functions. Their values depend only on the state of the system and not on the paths taken to reach their values.
b) Entropy: We cannot measure entropy; we always measure the change of entropy. Entropy is disorderness, which is also path independent and depends on its initial and final points. So, entropy is a state function.