Quantitative Applications - Precipitation Titration

 Quantitative Applications

Precipitation titrimetry is rarely listed as a standard method of analysis, but may still be useful as a secondary analytical method for verifying results obtained by other methods. Most precipitation titrations involve Ag+ as either an analyte or titrant. 

Those titrations in which Ag+ is the titrant are called argentometric titra- tions. Table 9.22 provides a list of several typical precipitation titrations.


Quantitative Calculations 

The stoichiometry of a precipitation reaction is given by the conservation of charge between the titrant and analyte; thus


Example 9.17 shows how this equation is applied to an analysis based on a direct titration.


The analysis for I– using the Volhard method requires a back titration. A typical calculation is shown in the following example.


Comments

Post a Comment

Popular posts from this blog

Where to Sample the Target Population

Image
  Where to Sample the Target Population Sampling   errors   occur   when   a   sample’s   composition   is   not   identical   to   that   of   the population   from   which   it   is   drawn.   When   the   material   being   sampled   is   homoge- neous,   individual   samples   can   be   taken   without   regard   to   possible   sampling   errors. Unfortunately,   in   most   situations   the   target   population   is   heterogeneous   in   either time   or   space.   As   a   result   of   settling,   for   example,   medications   available   as   oral   sus- pensions   may   have   a   higher   concentration   of   their   active   in...
Read more

Basic Components of Spectroscopic Instrumentation

Image
  Basic Components of Spectroscopic Instrumentation The   instruments   used   in   spectroscopy   consist   of   several   common   components, including   a   source   of   energy   that   can   be   input   to   the   sample,   a   means   for   isolat- ing   a   narrow   range   of   wavelengths,   a   detector   for   measuring   the   signal,   and   a   sig- nal   processor   to   display   the   signal   in   a   form   convenient   for   the   analyst.   In   this section   we   introduce   the   basic   components   used   to   construct   spectroscopic   in  struments. Sources of Energy All   forms   of   spectroscopy   require   a ...
Read more

Quantitative Applications - Coulometric Methods of Analysis

Image
  Quantitative Applications Coulometry   may   be   used   for   the   quantitative   analysis   of   both   inorganic   and   organic compounds. Examples of controlled-potential and controlled-current   coulometric methods   are   discussed   in   the   following   sections. Controlled-Potential Coulometry  The majority of controlled-potential coulometric analyses   involve   the   determination   of   inorganic   cations   and   anions,   including   trace metals   and   halides.   Table   11.8   provides   a   summary   of   several   of   these   methods. The ability to control selectivity by carefully selecting the working electrode’s potential,   makes   controlled-potential   coulometry   particularly   useful   for   the   analy...
Read more