Question

Which one of the following is a state property?
A. Heat
B. Work
C. Internal energy
D. Potential energy

Answer 1

State property does not depend upon the path followed by the process. State property depends only upon the initial and final state of the system.

Complete answer:
The thermodynamic properties which do not depend upon the path followed by the thermodynamic process are known as state properties. The thermodynamic properties which depend upon the path followed by the thermodynamic process are known as path properties.
Let us discuss the options one by one:
Heat is the mode of transfer of energy. Change in the heat depends upon the path followed by the thermodynamic process, so the heat is a path property.
So, option (A) is incorrect.
Work is also a mode of transfer of energy. Work also depends upon the path followed by the thermodynamic process, so the work is also a path function.
So, option (B) is incorrect.
Internal energy is the intrinsic property of the system. Internal energy only depends upon the initial and final state of the system, not on the path followed. So, the internal energy is a state function.
So, option (C) is correct.
Potential energy is the energy stored by a substance in a position. Potential energy does not depend upon the path followed. So, the potential energy is also a state function.
So, option (D) is correct.

Therefore, option (C) internal energy and potential energy (D) both are correct.

Note: The heat, heat capacity, and work only these are the path functions rest all thermodynamic properties are state functions. All forms of energy are state function. According to the first law, work can be state function at constant heat and heat can be a state function at constant volume.