1. Standard state and thermodynamic functions

The tables presented in these forms give standard thermodynamic quantities, marked with a superscript "°", for example :

Δ _f H ° : standard enthalpy of formation

Δ _f G°: standard free enthalpy of formation

S°: entropy of formation

As a standard quantity is a function of temperature, standard quantities are often given, by convention, at a temperature of 298.15 K (abbreviated to 298 in the formulas for simplicity).

When writing a chemical reaction, when it is necessary to specify the state of the constituents, the following symbolism is used:

< > : solid

( ) : liquid

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