Calorimetric methods isoperibol calorimeter

One important factor, which influences the selection of the measurement method, is the duration of the chemical reaction investigated. For fast reactions, i.e. when the reaction is over at least within 30 min, the most suitable calorimeter is the isoperibolic calorimeter, since the heat effect can be determined quite precisely. The reaction proceeds in the calorimetric vessel, provided with a thermocouple, the drop-device of one component into the other, and the stirrer. The calorimetric cover is heated to a constant temperature. At the measurement of heats of mixing, respectively of heats of dissolution, both liquid components must be thoroughly heated before mixing to the same temperature before mixing. This can be made in such a way that the one component is placed just above the other one in a second crucible, which is then overturned or immersed and both components are mixed. 

Basically, the methods consist of a variety of calorimetric methods and a few non-calorimetric methods. In calorimetry the following methods are nsed adiabatic, isoperibol, isothermal, heat condnction, drop and differential scanning calorimeters, and differential thermal analysis. Cryoscopic, vapor pressure, and enthalpy of solution methods are considered to be non-calorimetric methods. 

Titration calorimetry is a method in which one reactant inside a calorimetric vessel is titrated with another delivered from a burette at a controlled rate. This technique has been adapted to a variety of calorimeters, notably of the isoperibol and heat flow types [194-198]. The output of a titration calorimetric experiment is usually a plot of the temperature change or the heat flow associated with the reaction or physical interaction under study as a function of time or the amount of titrant added. 

Heat-flow Calorimeters.— In calorimeters of the adiabatic or isoperibol types, heat-exchange between the calorimeter and its surroundings is either eliminated or is restricted to a small, accurately determined amount. An alternative method is to transfer the heat of reaction completely to a heatsink, so that both the calorimeter and the heat-sink remain essentially isothermal and the calorimetric determination consists of measuring the heat transferred. Two main types have been employed. 

---