Cell emf

Emf cells are standard tools to elucidate thermodynamic formation data. Table 9 gives various examples (the underlined compounds are the ones for which thermodynamic data have been measured). 

Calomel Electrode. In addition to pH measnrements, there are many other emf cell measurements for which it is convenient to nse the calomel electrode as a reference electrode against which a measuring electrode is compared. Actnally this electrode is really a half-cell that is connected via a KCl salt bridge to another half-cell containing the solution of interest. The saturated calomel electrode can be written as... 

Electromotive force (emf) cell potential when a cell is operated reversibly... 

The standard deviation of the emf cell (II) at the mid-temperature was estimated to be as much as 11.4 mV, since there were noticeable differences in the emf for mixtures with P/Th ratios of I.2I, 1.15 and I.OI, particularly the last. This may be due to non-stoichiometiy in ThP , or the greater effect of oxygen contamination near the stoichiometric composition of the monophosphide, or to slow attainment of equilibrium. 

There are three sets of measurements of the thorium-bismuth system two relatively corrsistent emf studies around 1000 K, and a Knudsen study which is more difficult to interpret. Wiswall and Egan [1963WIS/EGA] have reported thorium activities in un-satrrrated solutiorrs in bismuth, measured in an emf cell involving ThCp dissolved in... 

The Gibbs energy of formation of ThF4(cr) was determined at 873 K with emf cells using a Cap2 solid electrolyte and AI/AIF3, UF3/UF4 and U/UF3 counter electrodes. 

Calculate standard emfs (cell potentials), cell> from standard reduction potentials. (Section 20.4)... 

Two test series have to be done, including measurements in two nearly identical cells, an emf cell with transference and a cell without transference the ceU without transference includes a salt bridge. Both cells have different molal concentrations in their half cells that is the... 

Other types of salt bridges consist of electrolyte-saturated linen wicks or bundles of camel s hair. These are useful when one wishes to minimize the trauma to delicate tissues which occurs with electrode contact. Occasionally linen membranes are used in half-cells to maintain the physical position of the reactants, especially in standard emf cell construction. 

One important variation of the hydrogen concentration cell, the flowing emf cell was developed by Sweeten et al. for studies of volatile reactants. The cell, shown in Fig. 16, comprises of two electrode chambers and a hquid junchon chamber. The lateral holes in the bottom of each piece allow solution to come in from each electrode chamber and then flow upwards into grooves cut in... 

---