Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Lanthanum Chloride, Hydrated 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
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ABSTRACT This monograph for Lanthanum Chloride, Hydrated 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, Calcium and Magnesium.
LaCl3 • (6–7)H2O
CAS No. 10099-58-8
Note: This reagent is available in degrees of hydration ranging from 6 to 7 molecules of water.
GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . .
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colorless or white solid matrix modification melting point, 91 °C, with decomposition very soluble
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64.5–70.0% LaCl3 Maximum Allowable Insoluble matter . . . . . . . . . . . . . . . . . . . . . 0.01% Calcium (Ca) . . . . . . . . . . . . . . . . . . . . . . . 10 ppm Magnesium (Mg) . . . . . . . . . . . . . . . . . . . . . 10 ppm
© 2017 American Chemical Society
A
ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4185 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
TESTS Assay
Downloaded by CORNELL UNIV on May 7, 2017 | http://pubs.acs.org Publication Date (Web): February 28, 2017 | doi: 10.1021/acsreagents.4185
(By gravimetric determination of La). Weigh accurately about 0.8 g, dissolve in 25 mL of water, filter any undissolved material, and wash with water. Add 100 mL of 5% oxalic acid solution, digest on a hot plate (~100 °C) until the supernatant solution is clear. Filter through a fine ashless filter paper, wash the precipitate with 10 mL portions of 1% oxalic acid solution, and dry. Ignite in a muffle furnace at 900 °C for 30 min. Cool and weigh as La2O3. One gram of lanthanum oxide corresponds to 1.506 g of LaCl3.
Insoluble Matter [Part 2: Gravimetric Methods; Insoluble Matter]. Use 20.0 g dissolved in 100 mL of water.
Calcium and Magnesium (By flame AAS, [Part 2: Trace and Ultratrace Elemental Analysis; Atomic Absorption Spectroscopy; Analysis; Procedure for Flame AAS]).
For the Determination of Calcium and Magnesium
S a m p l e S t o c k S o l u t i o n . Dissolve 5.0 g of sample in 40 mL of water, transfer to a 50 mL volumetric flask, and dilute to the mark with water (1 mL = 0.10 g).
For the Determination of Calcium and Magnesium
Element
Wavelength (nm)
Sample Wt (g)
Standard Added (mg)
Flame Type*
Background Correction
Ca
422.7
1.0
0.01; 0.02
N/A
No
Mg
285.2
1.0
0.005; 0.01
A/A
Yes
*A/A is air/acetylene; N/A is nitrous oxide/acetylene.
© 2017 American Chemical Society
B
ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4185 ACS Reagent Chemicals, Part 4
