Van’t Hoff equilibrium box

Solution Figure 15.2 shows a large box containing the reactant and product species in equilibrium at temperature T and pressure P. It is known as a van t Hoff equilibrium box. Material is added and withdrawn through semipermeable membranes that separate the four piston/cylinder assemblies from the box. Each semipermeable membrane permits the passage of only the pure species in its adjacent cylinder. 

A useful expression for the temperature dependence of the equilibrium constant is the van t Hoff equation (equation 3.23), which may be derived as outlined in Box 3.3. A more general form of this equation is -AH ... 

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