Which of the following are not state functions of state variables?
(i) Internal energy
(ii) Heat
(iii) Work
(iv) Volume

Options

A. (i),(ii),(iii),(iv)
B. (i),(iv)
C. (ii),(iii)
D. (ii),(iv)

Answer

C

Explanation

State function is a proterty of a system that depends only on its present state, which is completely determined by variables such as temperature and pressure. Thus. Internal energy and volume are state function. On the other hand, heat and work are not state functions becasue they are not properties of a system. We cannot say that a system has more heat or less heat, it has more work or less work. Heat and work manifest themselves only during a process (during a change of state). Thus, their values depend upon the path of the process and will vary accordingly.