Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Potassium Periodate (Potassium Metaperiodate) Part 4, Monographs for Reagent Chemicals: General Descriptions, Specifications, and Tests eISBN: 9780841230460 Tom Tyner Chair, ACS Committee on Analytical Reagents James Francis Secretary, ACS Committee on Analytical Reagents
ABSTRACT This monograph for Potassium Periodate provides, in addition to common physical constants, a general description including typical appearance, applications, change in state (approximate), and aqueous solubility. The monograph also details the following specifications and corresponding tests for verifying that a substance meets ACS Reagent Grade specifications including: Assay, Other Halogens, and Manganese.
KIO4
Formula Wt 230.00
CAS No. 7790-21-8
GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . .
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white solid oxidizing agent; determination of manganese melting point, 582 °C, with decomposition 0.42 g in 100 mL at 20 °C
SPECIFICATIONS Assay (dried basis). . . . . . . . . . . . . . . . . . . . 99.8–100.3% KIO4 Maximum Allowable Other halogens (as Cl) . . . . . . . . . . . . . . . . . 0.01% Manganese (Mn) . . . . . . . . . . . . . . . . . . . . . 1 ppm
TESTS Assay (By titration of oxidative capacity). Weigh accurately about 1 g, previously dried over magnesium perchlorate or phosphorus pentoxide for 6 h. Dissolve in water, and dilute with water to 500 mL in a volumetric flask. To 50.0 mL in a glass-stoppered
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4300 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
flask, add 10 g of potassium iodide and 10 mL of a cooled solution of 25% sulfuric acid reagent solution. Allow to stand for 5 min, add 100 mL of cold water, and titrate the liberated iodine with 0.1 N sodium thiosulfate volumetric solution, adding starch indicator solution near the end point. Carry out a complete blank test and make any necessary correction. One milliliter of 0.1 N sodium thiosulfate corresponds to 0.002875 g of KIO4.
Other Halogens Dissolve 0.50 g in a mixture of 10 mL of water, and 16 mL of sulfurous acid and boil for 3 min. Cool, add 5 mL of ammonium hydroxide and 20 mL of 2.5% silver nitrate solution, and filter. Dilute the filtrate with water to 100 mL, and to 20 mL of this solution add 1.5 mL of nitric acid. Any turbidity should not exceed that produced by 0.01 mg of chloride ion (Cl) in an equal volume of solution containing 0.5 mL of ammonium hydroxide, 1.5 mL of nitric acid, and 1 mL of silver nitrate reagent solution.
Manganese Add 5.5 g to 85 mL of 10% sulfuric acid reagent solution. For the control, add 0.5 g of the sample and 0.005 mg of manganese ion (Mn) to 85 mL of 10% sulfuric acid reagent solution. Add 10 mL of nitric acid and 5 mL of phosphoric acid to each, boil gently for 10 min, and cool. Any pink color in the solution of the sample should not exceed that in the control.
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4300 ACS Reagent Chemicals, Part 4
