TITRATION

Titration Techniques

Overview

• Titration is a volumetric technique used to determine the unknown concentration of an analyte by reacting it with a solution of known concentration.

• Common types include:

  • Acid-base titration

  • Redox titration

  • Complexometric titration

  • Karl Fischer titration

Key Variants and Indicators

• Indicators: Chemical compounds that change color at a particular pH, helping to identify the endpoint of titration.

  • Common ones: Phenolphthalein, Methyl Orange.

• Karl Fischer Titration: Used to determine water content in organic compounds.

• Winkler Test: Determines dissolved oxygen in water using iodometric titration.

Processes Involved

• Acid-base Titration: Involves the neutralization between an acid and a base.

  • At the equivalence point, moles of acid equal moles of base.

• Complexometric Titration: Uses chelating agents (like EDTA) to bind metal ions in solution.

• Redox Titration: Involves oxidation-reduction reactions, often utilizing permanganate as self-indicating.

General Procedure

• Use a buret to dispense titrant into the analyte solution gradually.

• The endpoint is indicated by a color change due to the chosen indicator.

• The equivalence point is where the reaction is complete, ideally identified during the titration curve.

Important Concepts

• Exact Volumes: Ensuring minimal dilution during titration for accuracy is critical.

• pH at Equivalence Point: Varies by the strength of reactants involved (strong acid/base will have a neutral pH).

• Half-equivalence Point: pH equals pKa for weak acids.

Practical Applications

• Titration can quantify concentrations of chemicals in various contexts, including biochemistry, environmental science (e.g. Winkler test), and pharmaceuticals.

• It serves as a fundamental technique in laboratory settings for quantitative analysis.