Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Potassium Chlorate 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 Chlorate provides, in addition to common physical constants, a general description including typical appearance, applications, change in state (approximate), aqueous solubility, and density. The monograph also details the following specifications and corresponding tests for verifying that a substance meets ACS Reagent Grade specifications including: Assay, Insoluble Matter, Bromate, Chloride, Sulfate, Heavy Metals, Iron, Calcium, Magnesium, and Sodium.
KClO3
Formula Wt 122.55
CAS No. 3811-04-9
GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . . Density . . . . . . . . . . . . . . . .
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white or colorless solid source of oxygen melting point, 368 °C 7 g in 100 mL at 20 °C 2.3
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . ≥99.0% KClO3
Insoluble matter . . . Bromate (BrO3) . . . . Chloride (Cl) . . . . . Sulfate (SO4) . . . . . Heavy metals (as Pb) Iron (Fe) . . . . . . . . Calcium (Ca) . . . . .
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© 2017 American Chemical Society
Maximum Allowable 0.005% 0.015% 0.001% Passes test 5 ppm 3 ppm 0.002%
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DOI:10.1021/acsreagents.4282 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
Magnesium (Mg) . . . . . . . . . . . . . . . . . . . . . 0.002% Sodium (Na) . . . . . . . . . . . . . . . . . . . . . . . . 0.01%
TESTS Assay (By oxidation–reduction titration of chlorate). Weigh, to the nearest 0.1 mg, about 0.05 g of sample, and dissolve it with 10 mL of water in a 250 mL glass-stoppered flask. Add 50.0 mL of 0.1 N ferrous ammonium sulfate volumetric solution, cover the flask to prevent exposure to the air, and boil for 10 min. Cool, add 10 mL of 10% manganese sulfate solution (described below) and 5 mL of phosphoric acid, and titrate the excess ferrous ammonium sulfate with 0.1 N potassium permanganate volumetric solution. Run a blank in the same manner. One milliliter of 0.1 N ferrous ammonium sulfate corresponds to 0.002043 g of KClO3.
For the Assay
M a n g a n e s e S u l f a t e S o l u t i o n , 1 0 % . Dissolve 10.0 g of manganese sulfate monohydrate in 100 mL of water.
Insoluble Matter [Part 2: Gravimetric Methods; Insoluble Matter]. Use 20 g dissolved in 250 mL of water.
Bromate [Part 2: Direct Electrometric Methods; Specific Polarographic Procedures; Polarographic Procedure for Bromate and Iodate]. Use 1.0 g of sample and 0.5 g of calcium chloride dihydrate in 25 mL of solution. For the standard, add 0.15 mg of bromate ion (BrO3). Also prepare a reagent blank.
Chloride Dissolve 2.0 g in 40 mL of warm water, and filter if necessary through a chloride-free filter. Add 0.25 mL of nitric acid, free from lower oxides of nitrogen, and 1 mL of silver nitrate reagent solution. Any turbidity should not exceed that produced by 1.2 mg of chloride ion (Cl) in an equal volume of solution containing the quantities of reagents used in the test.
Sulfate Dissolve 5.0 g in 150 mL of water, filter if necessary, and add 1 mL of 10% hydrochloric acid reagent solution and 5 mL of 12% barium chloride reagent solution. No precipitate should be produced on standing for at least 8 h. (Limit about 0.002%.)
Heavy Metals [Part 2: Colorimetry and Turbidimetry; Heavy Metals (as Lead); Procedure for Heavy Metals, Method 1]. Dissolve 5.0 g in 20 mL of dilute hydrochloric acid (1:1). Evaporate the solution to dryness on a hot plate (~100 °C), add 5 mL more of dilute
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4282 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
hydrochloric acid (1:1), and again evaporate to dryness. Dissolve the residue in about 20 mL of water, and dilute with water to 25 mL. For the control, add 0.02 mg of lead ion (Pb) to 1.0 g of sample, and treat exactly as the 5.0 g of sample.
Iron [Part 2: Colorimetry and Turbidimetry; Iron; Procedure for Iron, Method 1 (Ammonium Thiocyanate)]. Dissolve 3.3 g in 20 mL of dilute hydrochloric acid (1:1), and evaporate to dryness on a hot plate (~100 °C). Add 5 mL of dilute hydrochloric acid (1:1), and again evaporate to dryness. Dissolve in 50 mL of dilute hydrochloric acid (1:25), and use the solution without further acidification. In preparing the control, use the residue from evaporation of 15 mL of hydrochloric acid.
Calcium, Magnesium, and Sodium (By flame AAS, [Part 2: Trace and Ultratrace Elemental Analysis; Atomic Absorption Spectroscopy; Analysis; Procedure for Flame AAS]).
For the Determination of Calcium, Magnesium, and Sodium
S a m p l e S t o c k S o l u t i o n . Dissolve 5.0 g in 25 mL of dilute hydrochloric acid (1:3), and digest in a covered beaker on a hot plate (~100 °C) until the reaction ceases. Uncover the beaker, and evaporate to dryness. Add 10 mL of dilute hydrochloric acid (1:3), and dilute to 100 mL with the hydrochloric acid (1:99) in a volumetric flask (1 mL = 0.05 g).
For the Determination of Calcium, Magnesium, and Sodium
Element
Wavelength (nm)
Sample Wt (g)
Standard Added (mg)
Flame Type*
Background Correction
Ca
422.7
1.0
0.02; 0.04
N/A
No
Mg
285.2
0.20
0.004; 0.008
A/A
Yes
Na
589.0
0.20
0.01; 0.02
A/A
No
*A/A is air/acetylene; N/A is nitrous oxide/acetylene.
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4282 ACS Reagent Chemicals, Part 4
