Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Barium Carbonate 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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A u t h o r i t a t i v e Ve r s i o n : This version is current as of 01 Feb 2019.
ABSTRACT This monograph for Barium Carbonate 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 in Dilute Hydrochloric Acid, Chloride, Water-Soluble Titrable Base, Oxidizing Substances, Sulfide, Calcium, Potassium, Sodium, Strontium, Heavy Metals, and Iron.
O
Ba2+
BaCO3
-O
O-
Formula Wt 197.34
CAS No.513-77-9
SUPPLEMENTS & UPDATES Published
Authoritative
01 Aug 2018
01 Feb 2019
28 Feb 2017
01 Jun 2016
Expired
01 Feb 2019
Type
Summary
Other Versions
Update
The Heavy Metals specification and test, including sample size, were updated to use ICP−OES.
Original
First on-line publication, based on 11th ed.
GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . .
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© 2018 American Chemical Society
white solid preparation of barium standard solutions decomposes at about 1300 °C into barium oxide and carbon dioxide insoluble
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ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI: 10.1021/acsreagents.4045.20190201 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99.0–101.0% BaCO3
Insoluble in dilute hydrochloric acid Chloride (Cl) . . . . . . . . . . . . . . . Water-soluble titrable base . . . . . . Oxidizing substances (as NO3). . . . . Sulfide (S) . . . . . . . . . . . . . . . . . Calcium (Ca) . . . . . . . . . . . . . . . Potassium (K) . . . . . . . . . . . . . . . Sodium (Na) . . . . . . . . . . . . . . . . Strontium (Sr) . . . . . . . . . . . . . . Heavy metals (by ICP−OES) . . . . . . Iron (Fe) . . . . . . . . . . . . . . . . . .
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Maximum Allowable 0.015% 0.002% 0.002 meq/g 0.005% 0.001% 0.05% 0.005% 0.02% 0.7% 0.001% 0.002%
TESTS Assay (By acid–base titrimetry). Weigh to the nearest 0.1 mg, 4 g of sample. Transfer to a 250 mL beaker, add 50 mL of water, and mix. Cautiously add exactly 50.0 mL of 1 N hydrochloric acid, boil, and cool. Add a few drops of bromphenol blue indicator solution, and titrate the excess acid with 1 N sodium hydroxide volumetric solution to the blue end point. One milliliter of 1 N hydrochloric acid corresponds to 0.0987 g of BaCO3. % BaCO3 =
[(50.0 × N HCl) − (mL × N NaOH)] × 9.87 Sample wt (g)
Insoluble in Dilute Hydrochloric Acid Cautiously dissolve 10 g in 100 mL of dilute hydrochloric acid (1:9), and dilute with water to 200 mL. Ignore any slight haze that is produced. Filter through a tared, preconditioned filtering crucible, wash thoroughly with dilute hydrochloric acid (1:9), and dry at 105 °C.
Chloride To 1.0 g, add 20 mL of water, and add dropwise, with stirring, about 2–3 mL of nitric acid. Filter if necessary through a chloride-free filter, wash with a little hot water, and dilute with water to 50 mL. To 25 mL of the solution, add 1 mL of silver nitrate reagent solution. Any turbidity should not exceed that produced by 0.01 mg of chloride ion (Cl) in an equal volume of solution containing the quantities of reagents used in the test.
Water-Soluble Titrable Base Shake 5.0 g for 5 min with 50 mL of carbon dioxide-free water, cool, and filter. To 25 mL of the filtrate, add 0.10 mL of phenolphthalein indicator solution. If a pink color is produced, it should be discharged by 0.50 mL of 0.01 N hydrochloric acid.
© 2018 American Chemical Society
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ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI: 10.1021/acsreagents.4045.20190201 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
Oxidizing Substances Place 0.10 g in a dry beaker. Cool the beaker thoroughly in an ice bath, and add 22 mL of sulfuric acid that has been cooled to ice-bath temperature. Allow the mixture to warm to room temperature, and swirl the beaker at intervals to effect gentle dissolution with slow evolution of carbon dioxide. When dissolution is complete, add 3 mL of diphenylamine reagent solution, and digest on a hot plate (~100 °C) for 90 min. Prepare a standard by evaporating to dryness a solution containing 0.005 mg of nitrate (0.5 mL of the nitrate standard solution) and 0.01 g of sodium carbonate. Treat the residue exactly like the sample. Any color produced in the solution of the sample should not exceed that in the standard.
Sulfide Dissolve 1.0 g in 10 mL of dilute acetic acid (1:4). As soon as dissolution is complete, add 1 mL of silver nitrate reagent solution. Any color after 5 min should not exceed that produced by 0.01 mg of sulfide ion (S) in an equal volume of solution containing the quantities of reagents used in the test.
Calcium, Potassium, Sodium, and Strontium (By flame AAS, [Part 2: Trace and Ultratrace Elemental Analysis; Atomic Absorption Spectroscopy; Analysis; Procedure for Flame AAS]).
For the Determination of Calcium, Potassium, Sodium, and Strontium
S a m p l e S t o c k S o l u t i o n A . Cautiously dissolve 10.0 g of sample in 50 mL of dilute hydrochloric acid (1:3) in a beaker. Transfer to a 100 mL volumetric flask, and dilute with water to the mark (1 mL = 0.10 g). S a m p l e S t o c k S o l u t i o n B . Pipette 10.0 mL of sample stock solution A into a 100 mL volumetric flask, and dilute to the mark with water (1 mL = 0.01 g). Add 2.0 mL of a 2.5% potassium chloride reagent solution to the flask for calcium and strontium.
For the Determination of Calcium, Potassium, Sodium, and Strontium
Element
Wavelength (nm)
Sample Wt (g)
Standard Added (mg)
Flame Type*
Background Correction
Ca
422.7
0.05
0.025; 0.05
N/A
Yes
K
766.5
0.40
0.02; 0.04
A/A
No
Na
589.0
0.05
0.01; 0.02
A/A
No
Sr
460.7
0.01
0.035; 0.07
N/A
Yes
*A/A is air/acetylene; N/A is nitrous oxide/acetylene.
Heavy Metals [Part 2: Trace and Ultratrace Elemental Analysis; Inductively Coupled Plasma−Optical Emission Spectroscopy (ICP−OES)]. Sample size 1 g.
Iron Cautiously dissolve 1.0 g in 15 mL of dilute hydrochloric acid (1:2). For the standard, add 0.02 mg of iron (Fe) to 15 mL of dilute hydrochloric acid (1:2). Evaporate both solutions to dryness on a hot plate (~100 °C). Dissolve each residue in about 20 mL of water, add 4 mL of hydrochloric acid, and dilute with water to 100 mL. To 50 mL of each solution, add 0.10 mL of 0.1 N potassium permanganate, allow to stand for 5 min, and add 3 mL of ammonium thiocyanate reagent solution. Any red color in the solution of the sample should not exceed that in the standard.
© 2018 American Chemical Society
C
ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI: 10.1021/acsreagents.4045.20190201 ACS Reagent Chemicals, Part 4
