Iodometeric Titration Experiment solutions/Procedure [IOE TU]

Iodometeric Titration Experiment 

Here in this post you will get the experiment solution of iodometeric titration by using this experiment we will determine the amount of residual chlorine in water by iodometeric titration.

The iodometric titration experiment is a type of redox titration used to determine the concentration of oxidizing agents such as chlorine, bromine, or dissolved oxygen in a solution. This method relies on the reaction between iodide ions (I⁻) and an oxidizing agent to produce iodine (I₂) in an acidic medium, followed by titration with a standardized solution of sodium thiosulfate (Na2S2O3).

Here is a general procedure for iodometric titration:

Materials and Chemicals used in Iodometeric Titration 

- Oxidizing agent solution

- Sodium thiosulfate (standardized solution)

- Potassium iodide (KI)

- Starch solution (indicator)

- Dilute sulfuric acid (H2SO4)

- Burette, pipettes, volumetric flasks, and other necessary lab equipment

Procedure:

Preparation:

1. Standardization of Sodium Thiosulfate Solution:

Prepare a standardized solution of sodium thiosulfate by titrating it against a known concentration of iodine solution.

 

The reaction involves iodine and thiosulfate, following a balanced equation:

       

            2S2O3²⁻ + I2 → S4O6²⁻ + 2I⁻.

 

Calculate the exact concentration of the thiosulfate solution based on the iodine solution's known concentration.

2.Preparation of Sample:

 

Prepare the solution containing the oxidizing agent (chlorine, bromine, etc.) in a flask.

Titration Procedure:

3.Adding Acid:

If the solution is not acidic, add a few drops of dilute sulfuric acid (H2SO4) to acidify the solution.

  

4.Adding Potassium Iodide:

Add excess potassium iodide (KI) to the solution. The iodide ions will react with the oxidizing agent, converting it to iodine.The reaction depends on the specific oxidizing agent present.

  

5.Titration with Sodium Thiosulfate:

Add the standardized sodium thiosulfate solution slowly to the iodine-containing solution until the yellow color of iodine fades to a pale straw color. At this point, add a few drops of starch solution as an indicator.The starch forms a blue-black complex with free iodine, aiding in detecting the endpoint.

6.Endpoint Determination:

Continue adding the thiosulfate solution drop by drop while swirling the flask until the blue-black color disappears, indicating the complete reaction of iodine with the thiosulfate.The disappearance of the blue-black color signifies the endpoint of the titration.

7.Calculations:

Use the volume and concentration of the thiosulfate solution consumed during titration to calculate the amount of iodine produced.Convert the amount of iodine produced back to the original oxidizing agent concentration using stoichiometry.

Safety Precautions:

Wear appropriate protective gear, including goggles and gloves.Work in a well-ventilated area due to the use of chemicals.Handle chemicals with care and follow laboratory safety guidelines.

Please note that the specific details and concentrations may vary based on the oxidizing agent being tested and the experimental conditions. Always refer to specific laboratory procedures and protocols for accurate and safe execution of the iodometric titration experiment.