Welcome to Chem Zipper.com......: What are the "State functions or State variables" ?

## Thursday, October 1, 2020

### What are the "State functions or State variables" ?

State Functions or State Variables are the physical quantity having a definite value at a particular (present state) state and value is independent from the fact how the system achieved that state.

Mathematical Condition for a function to be a state function:-
There are three conditions that must be satisfied simultaneously for a function to be state      function.

(i) If ∆φ is a state function

It means change in depends only on end states and not on the path which it followed       during the process.

(ii) If ∆φ is a state function

It implies, in cyclic integral as the end states are same, so ∆φ value will be zero.

(iii) If ∆φ = f(x, y) is a state function, Euler's reciprocity theorem must be satisfied.

If dz=0 then, are we sure that z = 0 state function ?

"Change in state function (z) is fixed in between two states so ∆z is also
a state function example ∆P,∆T,∆V,∆H= state function is a wrong statement"