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Acid-Base Titrations

Indicator Range Table

Definitions

• Acid-Base Titration
  
• • The process of using a known volume and concentration of acid (or base) to determine the [unknown] concentration of a known volume of a sample of base (or acid).


• Titrant
  
• The solution of known concentration and volume.
• The buret contains the titrant.
• Volume of titrant (your known volume) is determined by changes in the buret reading.


• Indicator
  
• The means for determining the state of the reaction system.
• Many indicators are chemical compounds that change color according to the state of the reaction environment.
• Indicators should be present in amounts that do not greatly effect the reaction under consideration.
• Usually they are present in concentrations that are several orders of magnitude smaller than that of the reactants. i.e. negligably small concentrations relative to the reactants and products.





Acid-Base Indicator Equilibrium: HIn H+ + In-

• Endpoint
  
  
  • The point at which the indicator changes state.
  • Usually associated with a change of color in the indicator.

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