Types of Titrations

Acid-Base Titrations

• Process: Involve the neutralization reaction between an acid and a base.

• Example: Determining the concentration of $HCl$ using $NaOH$ as the titrant.

Redox Titrations

• Process: Based on oxidation-reduction reactions where electrons are transferred between the analyte and the titrant.

• Example: Determining the concentration of $Fe^{2+}$ using $KMnO_4$ (Potassium Permanganate).

Complexometric Titrations

• Process: Involve the formation of a stable complex ion.

• Example: Determining metal ions (like $Ca^{2+}$ or $Mg^{2+}$) using EDTA as the complexing agent.

Precipitation Titrations

• Process: Based on a reaction that forms an insoluble precipitate.

• Example: Determining $Cl^-$ concentration using $AgNO_3$ (Argentometric titration), which forms a white $AgCl$ precipitate.

Key Terms

• Equivalence Point: The point at which the moles of acid equal the moles of base. For strong acid-strong base titrations, this occurs at $pH = 7$.

• End Point: The point where the indicator changes color, ideally very close to the equivalence point.

• Indicators: Substances chosen to change color at the specific pH of the equivalence point.

  • Phenolphthalein: Colorless in acid, pink in base ($pH$ range 8.2–10).

  • Methyl Orange: Red in acid, yellow in base ($pH$ range 3.1–4.4).