QUANTITATIVE DETERMINATION OF COPPER CONCENTRATION IN AQUEOUS SOLUTION BY IODOMETRIC TITRATION
EXPERIMENT 8
QUANTITATIVE DETERMINATION
IODOMETRIC TITRATION
OF COPPER CONCENTRATION IN
AQUEOUS SOLUTION B Y
RESULTS AND DISCUSSION
Considered as moderately weak oxidizing agent, Iodine was used for the determination of strong reductants. Standard iodine solutions were found to have smaller electrode potentials as compared with the other oxidants, gaining them the advantage of imparting a degree of selectivity essential in the determination of strong reducing agents amid the presence of weak agents. Although regular re-standardization was essential for Iodine solution due to its lack of stability, it was still suitable for titrations due to its advantage of having sensitive and reversible indicator [5].
Reduction-oxidation titrations involving iodine were classified mainly into two; Iodimetry and Iodometry. Iodimetry was a direct method involving only one reaction between the titrant and the analyte [6].
(
)(
(
)
)(
(
(
)
)
)
In Reaction 1, the analyte of unknown concentration was titrated against the standard Iodine solution.
It reduced the titrant, Iodine (I2), into Iodide; while the titrant acted as oxidizing agent to the analyte.
The reduction of iodine was dependent on the strength of its reducing agents; weakest reducing agents do not proceed to completion due to Iodine’s comparatively weak oxidizing capacity; stronger reducing agents were favored only under neutral conditions. However, even in acidic solutions, strong reducing agents could proceed into completion without difficulty. Reducing agents: sulfide, sulfite, thiosulfate, arsenite, ferrocyanide, stannous, and antimonous ions were determined to be strong reducing agents, enough to reduce Iodine; this limit therefore, implicates the few titrations which involve Iodimetry [6].
Iodometry, on the other hand was an indirect method which allowed the reaction of oxidizing agents with neutral or acidic solution of a soluble Iodide. In this method,
QUANTITATIVE DETERMINATION
IODOMETRIC TITRATION
OF COPPER CONCENTRATION IN
AQUEOUS SOLUTION B Y
RESULTS AND DISCUSSION
Considered as moderately weak oxidizing agent, Iodine was used for the determination of strong reductants. Standard iodine solutions were found to have smaller electrode potentials as compared with the other oxidants, gaining them the advantage of imparting a degree of selectivity essential in the determination of strong reducing agents amid the presence of weak agents. Although regular re-standardization was essential for Iodine solution due to its lack of stability, it was still suitable for titrations due to its advantage of having sensitive and reversible indicator [5].
Reduction-oxidation titrations involving iodine were classified mainly into two; Iodimetry and Iodometry. Iodimetry was a direct method involving only one reaction between the titrant and the analyte [6].
(
)(
(
)
)(
(
(
)
)
)
In Reaction 1, the analyte of unknown concentration was titrated against the standard Iodine solution.
It reduced the titrant, Iodine (I2), into Iodide; while the titrant acted as oxidizing agent to the analyte.
The reduction of iodine was dependent on the strength of its reducing agents; weakest reducing agents do not proceed to completion due to Iodine’s comparatively weak oxidizing capacity; stronger reducing agents were favored only under neutral conditions. However, even in acidic solutions, strong reducing agents could proceed into completion without difficulty. Reducing agents: sulfide, sulfite, thiosulfate, arsenite, ferrocyanide, stannous, and antimonous ions were determined to be strong reducing agents, enough to reduce Iodine; this limit therefore, implicates the few titrations which involve Iodimetry [6].
Iodometry, on the other hand was an indirect method which allowed the reaction of oxidizing agents with neutral or acidic solution of a soluble Iodide. In this method,