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TITRIMETRIC METHODS OF ANALYSIS

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					TITRIMETRIC METHODS OF
       ANALYSIS



  BASICS OF ANALYTICAL CHEMISTRY
   PROF.DR.ENDANG ASIJATI M.Sc.
         Titrimetric Methods


• Includes a group of analytical methods that
  are based upon determining the quantity of a
  reagent of unknown strength that is required
  to react completely with the analyte.
            Titrimetric Methods
• Volumetric titrimetry
   – A type of titrimetry in which the standard reagent is
     measured volumetrically.
• Gravimetric titrimetri
   – A type of titrimetry in which the mass of the standard
     reagent is measured.
• Coulometric titrimetry
   – A type in which the quantity of charge in coulombs
     required to complete a reaction with the analyte is
     maesured.
                  Titration?
• A process in which a standard reagent is
  added to a solution of an analyte until the
  reaction between the analyte and the reagent
  is judge to be complete.
• Back-titration
  – A process in which the excess of a standard
    solution used to react with an analyte is
    determined by titration with a second standard
    solution.
     Equivalence and end Points
• Equivalence point
  – Related to the amount (mol/mek)
• End point
  – Related to the physical sign that associate with the
    condition of chemical equivalence.
  The end point is express in range, the range should
    address to the equivalence point.
                  Standard?
• Standard Solution
  – A primary standard
  – A secondary standard
• Standardization
  – A process in which concentration of a volumetric
    solution is determined by using it to titrate a
    known mass of a primary standard.
          PRIMARY STANDARD
•   HIGH PURITY
•   ATMOSPHERIC STABILITY
•   INDEPENDENT OF HUMIDITY
•   MODEST COST
•   LARGE MOLAR MASS
      ALGEBRAIC RELATIONSHIP
• AT THE EQUIVALENCE POINT
  – Equivalent A = Equivalent B
  – Mol A = Mol B (if the reaction is 1:1)
 TITRATION CURVES FOR WEAK ACIDS
• At the beginning, the solution contains only a weak
  acid or a weak base, and the pH is calculated from
  the concentration of that and its dissociation
  constant.
• After various increment of titrant have been added,
  the solution consists of a series of buffers. The pH of
  each buffer can be calculated from the analytical
  concentration of the conjugate base or acid and the
  residual concentration of the weak acid or base.
 TITRATION CURVES FOR WEAK ACIDS
• At equivalence point, the solution contains only the
  conjugate of the weak acid or base being titrated,
  and the pH is calculated from the concentration of
  this product
• Beyond the equivalence point, the excess of strong
  acid or base titrate represses the acidic or basic
  character of the reaction product to such an extent
  that the pH is governed largely by the concentration
  of the excess titrant.

				
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Description: TITRIMETRIC METHODS OF ANALYSIS