Adiabatic calorimetry

The pair of insulated vessels in Fig. 11.21 are equipped with, in addition to temperature measuring devices (thermocouples, not thermometers as shown), provisions for heating or cooling the contents. The vessel (or cell) on the left contains a reference aqueous solution, meaning one without the reactive substance that is dissolved in the right-hand cell. The system can be operated in either of two modes.

Titration mode

In the first mode, reactant is periodically injected into the right-hand cell and, at a constant cooling rate, the AT between the left and right cells is recorded. As seen in Fig. 11.21, the temperature spikes at each reactant injection (if the reaction is exothermic), and returns to the base temperature by the continuous cooling. Each temperature pulse represents the heat evolved by partial uptake of the injected reactant (often a ligand) by the reactant in the vessel (a macromolecule). As the number of injections increases, the reaction sites on the macromolecule become saturated, and the height of the spikes decreases and eventually vanishes.

What follows is a theoretical model of the "data" shown in Fig. 11.22. For this analysis, the conditions of the experiment are assumed and the thermodynamic properties of the ligand binding reaction with the sites on the macromolecule are calculated. For the purposes of illustrating the method, the simplest system consisting of identical and independent binding sites analyzed in Sect. 11.6.1 is treated.

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Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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