Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Chloroplatinic Acid Hexahydrate (Hexachloroplatinic Acid Hexahydrate; Platinic Chloride Hexahydrate)
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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 Chloroplatinic Acid Hexahydrate 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, Solubility in Alcohol, Alkali, Other Salts, and Suitability for Potassium Determinations.
H2PtCl6·6H2O
Formula Wt 517.91
CAS No. 16941-12-1
GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . .
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brownish-yellow solid determination of potassium melting point, 60 °C soluble
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . ≥37.50% Pt Maximum Allowable Solubility in alcohol . . . . . . . . . . . . . . . . . . . Passes test Alkali and other salts (as sulfates). . . . . . . . . . 0.05% Suitability for potassium determinations. . . . . . Passes test
© 2017 American Chemical Society
A
ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4092 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
TESTS Assay
Downloaded by CORNELL UNIV on June 12, 2017 | http://pubs.acs.org Publication Date (Web): February 28, 2017 | doi: 10.1021/acsreagents.4092
(By electrolytic determination of platinum content). Using precautions to prevent absorption of moisture, weigh accurately 1 g, and transfer to a tared, preconditioned platinum dish of about 100 mL capacity. Dissolve in 80 mL of water, and add 2 mL of sulfuric acid. Cover the dish with a split watch glass, and electrolyze the solution for 4 h at a current of 0.5 A and a temperature 55–60 °C and then for 1½ h at 1 A, using a rotating platinum anode and the platinum dish as the cathode. Wash the cover several times during the electrolysis. When the electrolysis is complete, transfer the solution to a second tared, preconditioned platinum dish, and reserve for the alkali and other salts test. Rinse the platinum dish and deposited platinum with water, dry, and ignite at 600 °C for 5 min. The weight of the deposit should not be less than 37.50% of the sample weight. All weighings must be determined to ±0.00002 g.
Solubility in Alcohol Dissolve 1.0 g in 10 mL of alcohol, and allow to stand, with occasional stirring, for 15 min. The solution should contain no more than traces of insoluble matter.
Alkali and Other Salts Evaporate the solution retained from the assay in a tared, preconditioned dish, and ignite at 600 ± 25 °C for 30 min.
Suitability for Potassium Determinations Dissolve 7.456 g of potassium chloride, previously dried at 105 °C, in water, and dilute with water to 1 L in a volumetric flask. To a 10 mL aliquot of this solution, add 0.100–0.110 g of sodium chloride, and dilute with water to 100 mL. Heat on a hot plate (~100 °C), and add between 0.90 and 1.00 g of the chloroplatinic acid crystals dissolved in about 1 mL of water. Evaporate the solution on a hot plate (~100 °C) to a moist residue. (Do not evaporate to dryness, as this will render the sodium salt insoluble.) Cool, and add 10 mL of absolute ethyl alcohol, crush the crystals with a glass stirring rod flattened on the end, and allow the mixture to stand for 30 min. Filter by decantation through a previously dried and weighed frittedglass crucible. Add 10 mL of absolute ethyl alcohol to the residue, grind the residue in the beaker, and filter again by decantation. When the filtrate runs clear, transfer the precipitate to the crucible, and wash with three 10 mL portions of alcohol. Discard the filtrate. Dry the filtering crucible in an oven at 105 °C for 1 h, cool, and weigh. The weight of the residue must not be less than 0.2410 g nor more than 0.2450 g.
© 2017 American Chemical Society
B
ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4092 ACS Reagent Chemicals, Part 4
