The standard Gibbs free energy of formation (''G''
f°) of a compound is the change of
Gibbs free energy
In thermodynamics, the Gibbs free energy (or Gibbs energy as the recommended name; symbol is a thermodynamic potential that can be used to calculate the maximum amount of Work (thermodynamics), work, other than Work (thermodynamics)#Pressure–v ...
that accompanies the formation of 1
mole
Mole (or Molé) may refer to:
Animals
* Mole (animal) or "true mole"
* Golden mole, southern African mammals
* Marsupial mole
Marsupial moles, the Notoryctidae family, are two species of highly specialized marsupial mammals that are found i ...
of a substance in its
standard state
The standard state of a material (pure substance, mixture or solution) is a reference point used to calculate its properties under different conditions. A degree sign (°) or a superscript ⦵ symbol (⦵) is used to designate a thermodynamic q ...
from its constituent elements in their standard states (the most stable form of the element at 1 bar of pressure and the specified temperature, usually 298.15 K or 25 °C).
The table below lists the standard Gibbs function of formation for several elements and chemical compounds and is taken from Lange's Handbook of Chemistry. Note that all values are in kJ/mol. Far more extensive tables can be found in the
CRC Handbook of Chemistry and Physics
The ''CRC Handbook of Chemistry and Physics'' is a comprehensive one-volume reference resource for science research. First published in 1914, it is currently () in its 105th edition, published in 2024. It is known colloquially among chemists as ...
and the NIST JANAF tables.
[M. W. Chase, NIST – JANAF Thermochemical Tables, 4th Edition, Journal of Physical and Chemical Reference Data, Monograph 9, 1998.] The
NIST
The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical s ...
Chemistry WebBook (see link below) is an online resource that contains
standard enthalpy of formation
In chemistry and thermodynamics, the standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy during the formation of 1 mole of the substance from its constituent elements in their reference state, w ...
for various compounds along with the
standard molar entropy
In chemistry, the standard molar entropy is the entropy content of one mole of pure substance at a standard state of pressure and any temperature of interest. These are often (but not necessarily) chosen to be the standard temperature and pressure ...
for these compounds from which the standard Gibbs free energy of formation can be calculated.
See also
*
Thermochemistry
Thermochemistry is the study of the heat energy which is associated with chemical reactions and/or phase changes such as melting and boiling. A reaction may release or absorb energy, and a phase change may do the same. Thermochemistry focuses on ...
*
Calorimetry
In chemistry and thermodynamics, calorimetry () is the science or act of measuring changes in '' state variables'' of a body for the purpose of deriving the heat transfer associated with changes of its state due, for example, to chemical reac ...
References
*
External links
NIST Chemistry WebBook
{{DEFAULTSORT:Gibbs free energy Of formation, Standard
Thermodynamic free energy