Uranyl Acetate Dihydrate - ACS Reagent Chemicals (ACS Publications)

Monograph pubs.acs.org/doi/book/10.1021/acsreagents

Uranyl Acetate Dihydrate 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

Downloaded by CORNELL UNIV on May 10, 2017 | http://pubs.acs.org Publication Date (Web): February 28, 2017 | doi: 10.1021/acsreagents.4417

ABSTRACT This monograph for Uranyl Acetate Dihydrate 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, Insoluble Matter, Chloride, Sulfate, Alkalis, Alkaline Earths, Heavy Metals, Iron, and Substances Reducing Permanganate.

UO2(CH3COO)2 • 2H2O

Formula Wt 424.14

CAS No. 6159-44-0

Note: The formula weight of this reagent is likely to deviate from the value cited because the natural distribution of uranium isotopes is often altered in current sources of uranium compounds.

GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . .

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greenish-yellow to bright yellow solid precipitant for sodium dehydrates, 110 °C 7.7 g in 100 mL at 15 °C; but solution slowly becomes cloudy due to formation of insoluble basic salt

SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98.0–102.0% UO2(CH3COO)2 · 2H2O Maximum Allowable Insoluble matter . . . . . . . . . . . . . . . . . . . . . 0.01% Chloride (Cl) . . . . . . . . . . . . . . . . . . . . . . . 0.003% Sulfate (SO4) . . . . . . . . . . . . . . . . . . . . . . . 0.01% Alkalis and alkaline earths (as sulfates) . . . . . . 0.05% Heavy metals (as Pb) . . . . . . . . . . . . . . . . . . 0.002%

© 2017 American Chemical Society

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ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.

DOI:10.1021/acsreagents.4417 ACS Reagent Chemicals, Part 4

ACS Reagent Chemicals

Monograph

pubs.acs.org/doi/book/10.1021/acsreagents

Iron (Fe) . . . . . . . . . . . . . . . . . . . . . . . . . . 0.001% Substances reducing permanganate (as UIV) . . . . 0.06%

TESTS Assay


(Total uranium by oxidimetry). Weigh accurately about 0.6 g, dissolve in 100 mL of 1 N sulfuric acid volumetric solution, and add enough 0.1 N potassium permanganate volumetric solution to give a distinct pink color. Pass 100 mL of 1 N sulfuric acid through a Jones reductor [Part 3: Reagents, Buffers, and Indicators; Solutions and Mixtures; Jones Reductor], followed by 100 mL of water, and discard. Pass the sample through the reductor, followed in succession by 100 mL each of 1 N sulfuric acid and water, and collect the effluent in a titration flask. Bubble air through the solution for 5–10 min, then titrate with 0.1 N potassium permanganate volumetric solution to a pink color. Run a reagent blank, and subtract it from the sample titration. One milliliter of 0.1 N potassium permanganate corresponds to 0.02121 g of UO2(CH3COO)2 · 2H2O.

Insoluble Matter Dissolve 10.0 g in 185 mL of water plus 5 mL of glacial acetic acid at room temperature. Filter through a tared, preconditioned filtering crucible, wash thoroughly with water, and dry at 105 °C.

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For the Determination of Chloride, Sulfate, Alkalis and Alkaline Earths, Heavy Metals, and Iron

S a m p l e S o l u t i o n A . Dissolve 15 g in 275 mL of water plus 5 mL of glacial acetic acid, add 10 mL of 30% hydrogen peroxide, and heat to coagulate the precipitate. Decant through a fritted-glass filter, without washing, and dilute with water to 300 mL (1 mL = 0.05 g).

Chloride† [Part 2: Colorimetry and Turbidimetry; Chloride]. Dilute 6.7 mL of sample solution A (0.34 g sample) with water to 20 mL.

Sulfate† [Part 2: Colorimetry and Turbidimetry; Sulfate; Procedure for Sulfate, Method 1]. Use 10 mL of sample solution A (0.5 g sample).

Alkalis and Alkaline Earths† To 40 mL of sample solution A (2 g sample), add 0.10 mL of sulfuric acid, evaporate to dryness, and gently ignite at about 450 °C. Digest the residue with 25 mL of hot water, filter, evaporate the filtrate to dryness in a tared, preconditioned dish, and ignite at 600 ± 25 °C for 15 min.


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Monograph

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Heavy Metals

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[Part 2: Colorimetry and Turbidimetry; Heavy Metals (as Lead); Procedure for Heavy Metals, Method 1]. Evaporate 20 mL of sample solution A (1 g sample) to dryness, dissolve the residue in about 20 mL of water, and dilute with water to 25 mL.

Iron† [Part 2: Colorimetry and Turbidimetry; Iron; Procedure for Iron, Method 1 (Ammonium Thiocyanate)]. Evaporate 20 mL of sample solution A (1 g sample) to dryness, dissolve the residue in 2 mL of hydrochloric acid, and dilute with water to 50 mL. Use the solution without further acidification.


Substances Reducing Permanganate Prepare two solutions, each containing 3.0 g in 200 mL of dilute sulfuric acid (1:99). Titrate one solution with 0.1 N potassium permanganate volumetric solution. Not more than 0.20 mL of permanganate should be required to cause a color change that can be observed by comparison with the solution not titrated. The 0.20 mL includes the 0.05 mL allowed to produce the color change in the absence of uranous compounds.


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Uranyl Acetate Dihydrate - ACS Reagent Chemicals (ACS Publications)

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