Ion-Exchange Heat Measurement

FIGURE 7.7 Thermostat of the heat-flow microcalorimeter showing the sample cell with the solution and the ion exchanger separated by a membrane to prevent ion exchange and to guarantee the initial state of the experiment. 

In the final state, that is, after the exchange, nB moles of the cation B pass from the solid to the solution, and n A moles pass from the solution to the zeolite. 

The Physical Chemistry of Materials Energy and Environmental Applications 

Besides, it is possible to define the differential heat of ion exchange [39] as 

From the results reported in Table 7.1, it is possible to conclude that in the case of heulandite and mordenite zeolites with a relatively high Si/Al ratio (see Table 7.1), the selectivity sequence K NH4 Na Ca is related to the hydration heats (see Table 7.2 [43]) with the exception of the pairs NH4-K and Mg-Ca. These conclusions were verified by independent calorimetric studies carried out by other authors [42], 

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