The change in this quantity is equal to the maximum work accompanying a process, and a change in a system at constant temperature and volume is spontaneous if this decreases. 
The change in this quantity is equal to the maximum work accompanying a process, and a change in a system at constant temperature and volume is spontaneous if this decreases.  FTP, identify this thermodynamic quantity, defined as internal energy minus temperature times entropy, which is similar to the Gibbs free energy of a system.
The change in this quantity is equal to the maximum work accompanying a process, and a change in a system at constant temperature and volume is spontaneous if this decreases.  
Helmholtz energy