B.pharma 1st semester Notes pharmaceutical analysis unit - 4th- Redox Titrations
// Redox Titrations \\
• A Redox titration is a type of titration in which titrant and titrand react through and oxidation reduction reaction.
• The end point of a Redox titration is detected by using indicators.
Principles of Redox titration;
Reduction—
• The subtances can undergo reduction by followin.
• The addition of hydrogen.
•The removal of oxygen.
• The acceptance of electrons.
Example- fe³+→fe ²+
Oxidation—
• Addition of oxygen.
• Removal of hydrogen.
• Loss/ donation of electrons.
Example- fe²+ → fe³+
 |
Oxidising agents;
•An oxidising agent is a chemical species that causes that other reactant in a redox reaction to be oxidized, and it is always reduced in the process.
Example- Ag + , O², O³
Reducing agent;
• A reducing agent is a chemical species that causes the other reactant in a Redox reaction to be reduced and it is always oxidized in the process.
Example- Cu+ , fe²+ , Li+ , I-
Types of Redox Titrations;
Redox Titrations are following types;
1. Iodimetry
2. Iodometry
3. Bromatometry
4. Cerimetry.
5. Di chrometry
Iodimetry;
• When an analyte that is a reducing agent is titrated directly with a standard iodine solution the method is called iodimetry
• It is direct method of titration.
• I² is a weak oxidant and it can be reduced by the reductant .
 |
| Method of iodimetry |
Step involved—
• Take standard solution of iodine in the iodine flask.
• Add 1 ml of indicators solution.
i.e. - starch or Na Starch glycollate.
• Titrate the above solution by using an Elite solution present in the burette i.e.- Na²S²O³.
• at the equivalent point all I² will react with Na²S ²O³ and solution present in the iodine flask will be colourless.
In + 2I → No reaction
Iodometry;
•when an analyte i.e. an oxidizing agent is added to excess iodide to produce iodine called iodometry methods.
Steps.
Thankyou👍🙏
.
Comments