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2. Gibbs–Helmholtz equation - Wikipedia

   en.wikipedia.org/wiki/Gibbs–Helmholtz_equation

   The definition of the Gibbs function is = + where H is the enthalpy defined by: = +. Taking differentials of each definition to find dH and dG, then using the fundamental thermodynamic relation (always true for reversible or irreversible processes): = where S is the entropy, V is volume, (minus sign due to reversibility, in which dU = 0: work other than pressure-volume may be done and is equal ...

3. Enthalpy–entropy chart - Wikipedia

   en.wikipedia.org/wiki/Enthalpy–entropy_chart

   An enthalpy–entropy chart, also known as the H–S chart or Mollier diagram, plots the total heat against entropy, [1] describing the enthalpy of a thermodynamic system. [2] A typical chart covers a pressure range of 0.01–1000 bar, and temperatures up to 800 degrees Celsius. [3] It shows enthalpy in terms of internal energy , pressure and ...

4. Introduction to entropy - Wikipedia

   en.wikipedia.org/wiki/Introduction_to_entropy

   Thermodynamics. In thermodynamics, entropy is a numerical quantity that shows that many physical processes can go in only one direction in time. For example, cream and coffee can be mixed together, but cannot be "unmixed"; a piece of wood can be burned, but cannot be "unburned". The word 'entropy' has entered popular usage to refer to a lack of ...

5. Hess's law - Wikipedia

   en.wikipedia.org/wiki/Hess's_law

   Hess's law. Hess’ law of constant heat summation, also known simply as Hess' law, is a relationship in physical chemistry and thermodynamics [1] named after Germain Hess, a Swiss -born Russian chemist and physician who published it in 1840. The law states that the total enthalpy change during the complete course of a chemical reaction is ...

6. Fundamental thermodynamic relation - Wikipedia

   en.wikipedia.org/wiki/Fundamental_thermodynamic...

   The first law of thermodynamics states that: where and are infinitesimal amounts of heat supplied to the system by its surroundings and work done by the system on its surroundings, respectively. According to the second law of thermodynamics we have for a reversible process: Q {\displaystyle \mathrm {d} S= {\frac {\delta Q} {T}}\,} Hence:

7. Thermodynamic databases for pure substances - Wikipedia

   en.wikipedia.org/wiki/Thermodynamic_databases...

   Thermodynamic data is usually presented as a table or chart of function values for one mole of a substance (or in the case of the steam tables, one kg). A thermodynamic datafile is a set of equation parameters from which the numerical data values can be calculated. Tables and datafiles are usually presented at a standard pressure of 1 bar or 1 ...

8. Thermochemical equation - Wikipedia

   en.wikipedia.org/wiki/Thermochemical_equation

   Chemical equation showing the transfer of energy to/from outside the system. In thermochemistry, a thermochemical equation is a balanced chemical equation that represents the energy changes from a system to its surroundings. One such equation involves the enthalpy change, which is denoted with Δ H. In variable form, a thermochemical equation ...

9. Thermodynamic equations - Wikipedia

   en.wikipedia.org/wiki/Thermodynamic_equations

   The law was actually the last of the laws to be formulated. First law of thermodynamics. d U = δ Q − δ W {\displaystyle dU=\delta Q-\delta W} where. d U {\displaystyle dU} is the infinitesimal increase in internal energy of the system, δ Q {\displaystyle \delta Q} is the infinitesimal heat flow into the system, and.