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Standard solutions are generally prepared by dissolving a solute of known mass into a solvent to a precise volume, or by diluting a solution of known concentration with more solvent. [1] A standard solution ideally has a high degree of purity and is stable enough that the concentration can be accurately measured after a long shelf time. [2]
The analytical (total) concentration of a reactant R at the i th titration point is given by = + [] + where R 0 is the initial amount of R in the titration vessel, v 0 is the initial volume, [R] is the concentration of R in the burette and v i is the volume added. The burette concentration of a reactant not present in the burette is taken to be ...
Back titration is a titration done in reverse; instead of titrating the original sample, a known excess of standard reagent is added to the solution, and the excess is titrated. A back titration is useful if the endpoint of the reverse titration is easier to identify than the endpoint of the normal titration, as with precipitation reactions
Active mass was defined in the 1879 paper as "the amount of substance in the sphere of action". [14] For species in solution active mass is equal to concentration. For solids, active mass is taken as a constant. , a and b were regarded as empirical constants, to be determined by experiment.
An actual thermometric titration plot for the determination of a strong base with a strong acid is illustrated in Figure 3. Fig. 4b. Thermometric probe for Metrohm 859 Titrotherm thermometric titration system. The most practical sensor for measuring temperature change in titrating solutions has been found to be the thermistor.
The law of definite proportion was given by Joseph Proust in 1797. [2]I shall conclude by deducing from these experiments the principle I have established at the commencement of this memoir, viz. that iron like many other metals is subject to the law of nature which presides at every true combination, that is to say, that it unites with two constant proportions of oxygen.
The first potentiometric titration was carried out in 1893 by Robert Behrend at Ostwald's Institute in Leipzig. He titrated mercurous solution with potassium chloride, potassium bromide, and potassium iodide. He used a mercury electrode along with a mercury/mercurous nitrate reference electrode. He found that in a cell composed of mercurous ...
The chief advantage over other types of titration is the selectivity offered by the electrode potential, as well as by the choice of titrant. For instance, lead ion is reduced at a potential of -0.60 V (relative to the saturated calomel electrode), while zinc ions are not; this allows the determination of lead in the presence of zinc. Clearly ...