Task: Text Categorization
Input (English): First proposed by Lewis, it is related logarithmically to a gas's standard Gibbs free energy divided by the temperature and gas constant. At equilibrium, this quantity must be equal in both gas and liquid phases. Taking the derivative of the natural log of this function is equates it to the derivative of a reaction's chemical potential. Equal to the gas' pressure when the gas is ideal, FTP, identify this thermodynamic quantity which replaces partial pressure when working with real gases and describes the tendency of a substance to escape from its current phase, symbolized by f.
Output (English): Science