Question
Define: (i) State variables (ii) State functions.
Solution
(i) State variables : The measurable properties required to describe the state of the system are called state variables. For example temperature, pressure, volume, composition etc. are state variables.
(ii) State functions: A state function is a property of the system whose value depends on only upon the state of the system and is independent of the path or manner by which the state is reached. For example, pressure, volume, temperature, internal energy (E), enthalpy (H), entropy (S) etc. are state functions.
