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Dichromate titration of thallium(I)
S R Sagi1, G S Raju, K V Ramana
1Department of Chemistry Andhra University Waltair, India.
Talanta
|January 1, 1975
Summary
Formal redox potentials for the thallium(III)-thallium(I) couple were determined. Thallium(I) can be directly titrated using potassium dichromate in 6M hydrochloric acid, provided atmospheric oxygen is excluded.
Area of Science:
- Analytical Chemistry
- Electrochemistry
Background:
- The thallium(III)-thallium(I) redox couple is relevant in various chemical analyses.
- Understanding redox potentials is crucial for developing accurate titration methods.
Purpose of the Study:
- To report the formal redox potentials of the thallium(III)-thallium(I) couple in acids of varying strengths.
- To establish optimal conditions for the direct titration of thallium(I) with potassium dichromate.
Main Methods:
- Determination of formal redox potentials.
- Direct titration of thallium(I) using potassium dichromate.
- Utilized ferroin as an indicator in hydrochloric acid solutions.
- Controlled atmosphere by excluding atmospheric oxygen.
Main Results:
- The study reports formal redox potentials for the thallium(III)-thallium(I) couple.
- A minimum concentration of 5M hydrochloric acid is required for direct titration.
- Successful direct titration of thallium(I) with potassium dichromate was achieved in 6M hydrochloric acid at room temperature.
Conclusions:
- Direct titration of thallium(I) with potassium dichromate is feasible under specific conditions.
- 6M hydrochloric acid provides a suitable medium for this titration when ferroin is used as an indicator and oxygen is excluded.
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