Titration Argentometry

Theory
Term of argentometry derived from the Latin Argentum, the the which means silver. So, argentometry is one way to determine the levels of substances in a solution That Is performed with titration based on the formation of precipitate with Ag + ionsOne way to determine the levels of acid-base balance in a solution is by volumetry. Argentometry a precipitation titration samples analyzed by using silver ions. Typically, the ions are determined in this titration is halide ions (Cl-, Br-, I-). There are three types of end points Used for the titration with AgNO3namely: 1.Indikator2.Amperometri3.Indikator kimiaTitik end based on the potentiometric silver electrode potential is dipped into the analyte solution. Amperometri end point involves determining the current passed Between mikroelektrode pair of silver in a solution of analytes. While the end point produced chemical indicator, usually consists of changing colors Appear absence of turbidity in the titrated solution. Terms of indicators for precipitation titration analogdengan neutralization titration indicators, namely:
 1. Should color changes occur in a limited range of p-function of reagent / analyte.Color2. The changes must occur in parts of the titration curve for the analyte. In the titration argentometry, substances have been Spiked That examination is mixed with salt indicator of the standard solution of silver nitrate (AgNO3). By measuring the volume standar liquid Used so That all the Ag + ions be precisely deposited Cans, Cans salt in content inspection solution be determined. The methods of titration argentometry:1. Mohr Method; this method is Cans be Used to determine chloride levels in the atmosphere danbromide neutral with a standard solution of silver nitrate with potassium chromate as an indicator of the Addition of the solution. At the beginning of the titration will from silver chloride precipitation occur from and after the equivalent point, then adding a little silver nitrate will be reacting with chromate to form a precipitate of silver chromate red That2. Volhard method; Silver Cans be determined accurately in an atmosphere of raw with acid solution of potassium or ammonium thiocyanate, thiocyanate Cans set in the clear advantages with salts of iron (III) nitrate or iron (III) ammonium sulphate as indicator That form the red color of the complex of iron (III) thiocyanate in the environment 0.5 N nitric acid 1.5 N. This Should Be titration carried out in an atmosphere of acid, Because the iron ions (III) will be deposited into Fe (OH) 3 if the atmosphere is alkaline, so the end of point Cans not be demonstrated3. Fajans Method: In this method the adsorption indicator, as the fact That at the equivalent point indicator adsorbed by sediment. This indicator Gives no discoloration to the solution, but on the surface sedimentation. sedimentation Should Be maintained as far as possible in the form of colloid.