Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Stannous Chloride Dihydrate (Tin(II) Chloride Dihydrate)
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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 Stannous Chloride 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, Solubility in Hydrochloric Acid, Sulfate, Calcium, Iron, Lead, Potassium, and Sodium.
SnCl2 • 2H2O
Formula Wt 225.64
CAS No. 10025-69-1
GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . .
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white to off-white solid reducing agent melting point, 37–38 °C when heated rapidly 118 g in 100 mL at 0 °C
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98.0–103.0% SnCl2 · 2H2O Maximum Allowable Solubility in hydrochloric acid . . . . . . . . . . . . Passes test Sulfate (SO4) . . . . . . . . . . . . . . . . . . . . . . . Passes test Calcium (Ca) . . . . . . . . . . . . . . . . . . . . . . . 0.005% Iron (Fe) . . . . . . . . . . . . . . . . . . . . . . . . . . 0.003% Lead (Pb) . . . . . . . . . . . . . . . . . . . . . . . . . 0.01% Potassium (K) . . . . . . . . . . . . . . . . . . . . . . . 0.005% Sodium (Na) . . . . . . . . . . . . . . . . . . . . . . . . 0.01%
© 2017 American Chemical Society
A
ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4378 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 26, 2017 | http://pubs.acs.org Publication Date (Web): February 28, 2017 | doi: 10.1021/acsreagents.4378
(By titration of reductive capacity of SnII). In a weighing bottle, weigh accurately about 2.0 g. Transfer to a 250 mL volumetric flask, first with three 5 mL portions of hydrochloric acid and then with water through which high-purity nitrogen gas has been freshly bubbled to expel oxygen. Dilute to volume with similar water. Displace air from the headspace with nitrogen gas. Stopper and mix thoroughly. Place a 50.0 mL aliquot of this solution in a 500 mL conical flask filled with nitrogen gas. Add 5 g of potassium sodium tartrate tetrahydrate and 60 mL of a cold saturated solution of sodium bicarbonate. Titrate promptly with 0.1 N iodine volumetric solution to a blue color with starch indicator. One milliliter of 0.1 N iodine corresponds to 0.01128 g of SnCl2 · 2H2O.
Solubility in Hydrochloric Acid Dissolve 5.0 g in 5 mL of hydrochloric acid, heat to 40 °C if necessary, and dilute with 5 mL of water. The salt should dissolve completely.
Sulfate Dissolve 5.0 g in 5 mL of hydrochloric acid, dilute the solution with water to 50 mL, filter if necessary, and heat to boiling. Add 5 mL of 12% barium chloride reagent solution, digest in a covered beaker on a hot plate (~100 °C) for 2 h, and allow to stand for at least 8 h. No precipitate should be formed. (Limit about 0.003%.)
Calcium, Iron, Lead, Potassium, and Sodium (By flame AAS, [Part 2: Trace and Ultratrace Elemental Analysis; Atomic Absorption Spectroscopy; Analysis; Procedure for Flame AAS]).
For the Determination of Calcium, Iron, Lead, Potassium, and Sodium
S a m p l e S t o c k S o l u t i o n . Dissolve 20.0 g of sample in a mixture of 50 mL of water and 20 mL of hydrochloric acid. Heat to 50 °C if necessary. Cool to room temperature, transfer to a 100 mL volumetric flask, and dilute to the mark with water (1 mL = 0.20 g).
For the Determination of Calcium, Iron, Lead, Potassium, and Sodium
Element
Wavelength (nm)
Sample Wt (g)
Standard Added (mg)
Flame Type*
Background Correction
Ca
422.7
1.0
0.05; 0.10
N/A
No
Fe
248.3
4.0
0.12; 0.24
A/A
Yes
Pb
217.0
1.0
0.10; 0.20
A/A
Yes
K
766.5
0.20
0.01; 0.02
A/A
No
Na
589.0
0.20
0.01; 0.02
A/A
No
*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.4378 ACS Reagent Chemicals, Part 4
