Helmholtz free energy

(Also called Helmholtz function, work function.) A thermodynamic function of state that, in a reversible isothermal process, increases with work done on the system.

In typical notation the Helmholtz free energy is

where F is the Helmholtz free energy (sometimes designated as A), U is the internal energy, T is temperature, and S is the entropy. By use of the first law of thermodynamics for reversible processes, the rate of change of the Helmholtz free energy is given by

where W is the work done by the system.
Compare Gibbs function.

INDEX
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
0
1
2
3
4
5
6
7
8
9