Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Cadmium Chloride, Anhydrous 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 Cadmium Chloride, Anhydrous 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, Nitrate, Nitrite, Sulfate, Ammonium, Calcium, Copper, Lead, Potassium, Sodium, and Zinc, and Iron.
CdCl2
Formula Wt 183.31
CAS No. 10108-64-2
GENERAL DESCRIPTION Typical appearance . . . . . . . . . . . . . . . . . . . hygroscopic solid Applications . . . . . . . . . . . . . . . . . . . . . . . . preparation of cadmium standard; analysis of sulfides; testing of pyridine bases Change in state (approximate) . . . . . . . . . . . . melting point, 568 °C Aqueous solubility . . . . . . . . . . . . . . . . . . . . freely soluble
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . ≥99.0% CdCl2 Maximum Allowable Insoluble matter . . . . . . . . . . . . . . . . . . . . . 0.01% Nitrate and nitrite (as NO3) . . . . . . . . . . . . . . 0.003% Sulfate (SO4) . . . . . . . . . . . . . . . . . . . . . . . 0.01% Ammonium (NH4) . . . . . . . . . . . . . . . . . . . . 0.01% Calcium (Ca) . . . . . . . . . . . . . . . . . . . . . . . 0.01% Copper (Cu) . . . . . . . . . . . . . . . . . . . . . . . . 0.001% Lead (Pb) . . . . . . . . . . . . . . . . . . . . . . . . . 0.005% Potassium (K) . . . . . . . . . . . . . . . . . . . . . . . 0.02% Sodium (Na) . . . . . . . . . . . . . . . . . . . . . . . . 0.05%
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4070 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
Zinc (Zn) . . . . . . . . . . . . . . . . . . . . . . . . . . 0.05% Iron (Fe) . . . . . . . . . . . . . . . . . . . . . . . . . . 0.001%
TESTS Assay (By complexometric titration of cadmium). Weigh accurately about 0.4 g of sample, and dissolve in about 200 mL of water. Add 15 mL of a hexamethylenetetramine reagent solution and 50 mg of xylenol orange indicator mixture. Titrate with standard 0.1 M EDTA volumetric solution to a color change of red-purple to lemon yellow. One milliliter of 0.1 M EDTA corresponds to 0.01833 g of CdCl2.
Insoluble Matter [Part 2: Gravimetric Methods; Insoluble Matter]. Use 10 g dissolved in 150 mL of water. Retain the filtrate and washings for the test for sulfate.
Nitrate and Nitrite [Part 2: Colorimetry and Turbidimetry; Nitrate; Procedure for Nitrate, Method 1 (Brucine Sulfate)].
For the Determination of Nitrate and Nitrite
S a m p l e S o l u t i o n A . In a 50 mL centrifuge tube, dissolve 0.30 g in 3 mL of water by heating on a hot plate (~100 °C). Add 20 mL of nitrate-free sulfuric acid (2:1), and cool in an ice bath. Centrifuge for 10 min, decant the solution into a 50 mL volumetric flask, and dilute to 50 mL with brucine sulfate reagent solution. C o n t r o l S o l u t i o n B . In a 50 mL centrifuge tube, dissolve 0.30 g in 2 mL of water and 1 mL of nitrate ion (NO3) standard solution by heating on a hot plate (~100 °C). Add 20 mL of nitrate-free sulfuric acid (2:1), and cool in an ice bath. Centrifuge for 10 min, decant the solution into a 50 mL volumetric flask, and dilute to 50 mL with brucine sulfate reagent solution.
Continue with the procedure, starting with the preparation of blank solution C.
Sulfate [Part 2: Colorimetry and Turbidimetry; Sulfate; Procedure for Sulfate, Method 1]. Use 1/20 of sample retained from the test for insoluble matter. Allow 30 min for turbidity to form.
Ammonium Dissolve 1.0 g in 80 mL of water, and add with stirring 20 mL of freshly boiled 10% sodium hydroxide reagent solution. After allowing the precipitate to settle, dilute 10 mL of the clear supernatant liquid with water to 50 mL, and add 2 mL of Nessler reagent. Any color should not exceed that produced by 0.01 mg of ammonium ion (NH4) in an equal volume of solution containing 4 mL of 10% sodium hydroxide reagent solution and 2 mL of the Nessler reagent.
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4070 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
Calcium, Copper, Lead, Potassium, Sodium, and Zinc (By flame AAS, [Part 2: Trace and Ultratrace Elemental Analysis; Atomic Absorption Spectroscopy; Analysis; Procedure for Flame AAS]).
For the Determination of Calcium, Copper, Lead, Potassium, Sodium, and Zinc
S a m p l e S t o c k S o l u t i o n . Dissolve 10.0 g of sample in a 100 mL volumetric flask, add 5 mL of nitric acid, and dilute to the mark with water (1 mL = 0.1 g).
For the Determination of Calcium, Copper, Lead, Potassium, Sodium, and Zinc
Element
Wavelength (nm)
Sample Wt (g)
Standard Added (mg)
Flame Type*
Background Correction
Ca
422.7
0.20
0.02; 0.04
N/A
No
Cu
324.7
2.0
0.02; 0.04
A/A
Yes
Pb
217.0
2.0
0.10; 0.20
A/A
Yes
K
766.5
0.20
0.02; 0.04
A/A
No
Na
589.0
0.04
0.01; 0.02
A/A
No
Zn
213.9
0.04
0.01; 0.02
A/A
Yes
*A/A is air/acetylene; N/A is nitrous oxide/acetylene.
Iron [Part 2: Colorimetry and Turbidimetry; Iron; Procedure for Iron, Method 1 (Ammonium Thiocyanate)]. Use 1.0 g.
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4070 ACS Reagent Chemicals, Part 4
