Maximum Work of Chemical Reaction

Work can be done during any thermodynamic process, which in general can be used to increase the volume of the system or to overcome the resistance of the various forces acting on the system (e.g. electrical forces, magnetic, etc.). 

Maximum work in the given circumstances can be performed if the transition takes place reversibly. Each irreversibility reduces the work which can be performed by the system. The chemical reaction is also a thermodynamic transition and therefore may be associated with the work done. 

Maximum work of the chemical reaction is the sum of work or increase in the volume of system, and work done against all the forces acting on the system where 

Similarly to thermal effect, specific values are introduced the maximum work of the isothermal-isobaric reaction Lp ax and maximum work of isothermal-isochoric reaction Lvmax- These reactions must therefore take place in a system in contact with an environment of constant temperature in the case of an isothermal-isobaric reaction the pressure in the system must be equal to environmental pressure. Spontaneous chemical reaction tends to be an irreversible process and its implementation as a reversible transformation requires special conditions. 

One possible implementation of a chemical reaction as a thermodynamically reversible process was proposed by van t Hoflf. This method involves applying semi-permeable membranes that allow only one of the reactants involved in the reaction to pass. The van t Hoflf chamber, the device in which there is a thermodynamically reversible reaction, is presented in Fig. 2.1. It will be considered in the example that hydrogen combustion occurs in the gas phase reaction given by Eq. 2.2. 

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