Volumetric Methods

What is Volumetric Analysis?

Volumetric analysis is a technique used in analytical chemistry to quantify the concentration of an unknown substance in a solution. It involves adding a known volume of a solution with a known concentration (the titrant) to a solution containing the unknown substance (the analyte) until a chemical reaction occurs to completion.

How to Perform Volumetric Analysis

1. Prepare the analyte solution: Accurately measure a known mass or volume of the analyte and dissolve it in a suitable solvent.
2. Prepare the titrant solution: Accurately measure a known mass or volume of the titrant and dissolve it in a suitable solvent. The concentration of the titrant must be known precisely.
3. Calibrate the burette: Rinse the burette with the titrant solution and discard the rinsate. Fill the burette with the titrant solution and zero the burette reading.
4. Add the analyte solution to the titration flask: Transfer the analyte solution to a titration flask. Add a few drops of indicator, which will change color once the reaction is complete.
5. Titrate the analyte solution: Slowly add the titrant solution from the burette to the analyte solution while swirling the flask constantly. Observe the color change of the indicator.
6. Record the volume of titrant used: Continue adding the titrant solution until the indicator changes color permanently. Record the final volume of titrant used.
7. Calculate the concentration of the analyte: Use the volume of titrant used and the concentration of the titrant to calculate the concentration of the analyte in the solution.

Applications of Volumetric Analysis

• Determination of the concentration of acids and bases
• Analysis of metal ions
• Titration of oxidizing and reducing agents
• Determination of the purity of compounds