Electromotoric force

The electromotoric force (emf) of a cell depends on the ionic concentration of the solutions. To locate the equivalence point, the variation in emf is monitored as the concentration of the analyte changes. When the measured emf is plotted against the total volume of titrant added, the curve produced is similar to that of a titration curve Fig. 4. This technique has all the advantages of the conductometric method and gives an experimental curve from which the endpoint can be detected accurately. 

The standard electrode potentials (electromotoric forces, EMK, for different reduction reactions are tabulated in most textbooks on physical chemistry. - ... 

A galvanic cell consists, as we have seen, in principle of an oxidation component in a container that draws electrons through a wire from a reduction component in another solution. The driving force causing the transfer is called the cell potential or sometimes the electromotoric force (in short EMK). The unit for cell potentials is volt (in short V) defined as joules of work coulomb charge transferred. The electromotoric force is defined as ... 

Figure 7.34 Zr02 oxygen sensor, (a) Functional principle (b) Linear dependence of electromotoric force on oxygen partial pressure and temperature (Heywang, 1984).

Determination of the change of standard free enthalpy from the electromotoric force of a galvanic element... 

Such a reversible cell may be used as a source of external work by attaching its poles to the two plates of an electrostatic air-condenser, or to an ideal electromotor. Slight motions of the parts of these systems in one direction or the other against the external forces holding them in equilibrium, will yield or absorb external work, and cause corresponding currents to pass round the system. 

Fig. 15.25. Farinograph (according to Rohrlich and Thomas, 1967). The apparatus consists of a ther-mostated mixer or kneader (1), its blades are driven by an electromotor (2). The reaction torque acts through a lever system (4) of analytical balance precision on the indicator scale (5) simultaneously recorded on a strip chart recorder (6). The movement of the lever system is damped by an oil dash pot (3). The farinogram is a diagram of force versus time...

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