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In analytical chemistry, potentiometric titration is a technique similar to direct titration of a redox reaction. It is a useful means of characterizing an acid . No indicator is used; instead the electric potential is measured across the analyte , typically an electrolyte solution.
The main compartment of the titration cell contains the anode solution plus the analyte. The anode solution consists of an alcohol (ROH), a base (B), sulfur dioxide (SO 2) and KI. Typical alcohols that may be used include ethanol, diethylene glycol monoethyl ether, or methanol, sometimes referred to as Karl Fischer grade. A common base is ...
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]
Iodometry, known as iodometric titration, is a method of volumetric chemical analysis, a redox titration where the appearance or disappearance of elementary iodine indicates the end point. Note that iodometry involves indirect titration of iodine liberated by reaction with the analyte, whereas iodimetry involves direct titration using iodine as ...
The term also has two other, conflicting meanings. In titration, the titer is the ratio of actual to nominal concentration of a titrant, e.g. a titer of 0.5 would require 1/0.5 = 2 times more titrant than nominal. This is to compensate for possible degradation of the titrant solution.
If boric acid (or some other weak acid) was used, direct acid–base titration is done with a strong acid of known concentration. HCl or H 2 SO 4 can be used. Indirect back titration is used instead if strong acids were used to make the standard acid solution: strong base of known concentration (like NaOH) is used to neutralize the solution. In ...
Some examples of primary standards for titration of solutions, based on their high purity, are provided: [4] Arsenic trioxide for making sodium arsenite solution for standardisation of sodium periodate solution (until Ph. Eur. 3, Appendix 2001 also for iodine and cerium(IV) sulfate solutions, since Ph. Eur. 4, 2002 standardised by sodium ...
An example of back titration, the Volhard method, named after Jacob Volhard, involves the addition of excess silver nitrate to the analyte; the silver chloride is filtered, and the remaining silver nitrate is titrated against ammonium thiocyanate, [1] with ferric ammonium sulfate as an indicator which forms blood-red [Fe(OH 2) 5 (SCN)] 2+ at the end point: