Sodium perchlorate

Structural formula
General
Surname	Sodium perchlorate
other names	Irenate
Molecular formula	NaClO 4
Brief description	colorless and odorless, crystalline solid
External identifiers / databases
CAS number 7601-89-0 (anhydrous) 7791-07-3 (monohydrate) EC number 231-511-9 ECHA InfoCard 100,028,647 PubChem 522606 ChemSpider 22668 Wikidata Q408491
Drug information
ATC code	H03 BC
properties
Molar mass	122.44 g mol −1 (anhydrous) 140.46 g mol −1 (monohydrate)
Physical state	firmly
density	2.52 g cm −3 (anhydrous) 2.02 g cm −3 (monohydrate)
Melting point	Decomposition from 482 ° C (anhydrous) Decomposition from 130 ° C (monohydrate)
solubility	easy in water (2090 g l −1 at 15 ° C) good in DMSO (242 g l −1 at 25 ° C)
safety instructions
Please note the exemption from the labeling requirement for drugs, medical devices, cosmetics, food and animal feed GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary danger H and P phrases H: 271-302-319-373 P: 220-305 + 351 + 338
Thermodynamic properties
ΔH f 0	−382.75 kJ mol −1 .
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Sodium perchlorate is the sodium salt of perchloric acid .

Extraction and presentation

The industrial production takes place in so-called perchlorate cells. Sodium chlorate dissolved in water is electrolytically oxidized to sodium perchlorate . Sodium chloride can also be used as the starting substance, the cell first being operated as a chlorate cell and later (if the concentration of sodium chlorate is sufficient) as a perchlorate cell.

properties

Sodium perchlorate forms hygroscopic colorless crystals. The crystal system is orthorhombic , space group Cmcm (space group no.63 ) , with the lattice parameters a = 7.085, b = 6.526 and c = 7.048  Å at 299 K. A high temperature form is also known in which the perchlorate ions are disordered ( NaCl - Structure, lattice parameter a = 7.08 Å (588 K)).

Sodium perchlorate is very soluble in water and easily soluble in polar organic solvents.

Solubility in various solvents at 25 ° C
solvent		water	Methanol	Ethanol	n-propanol	acetone	Ethyl acetate
solubility	in g / 100 g solvent	209.6	51.36	14.71	4,888	51.745	9,649

use

The main purpose of all perchlorate salts is their use as an oxygen supplier in solid fuels . Instead of sodium perchlorate, however, ammonium perchlorate is usually used, which is industrially produced in an ion exchange reaction by reacting the sodium salt with an ammonium salt :

${\displaystyle \mathrm {NaClO_{4}+NH_{4}Cl\longrightarrow NH_{4}ClO_{4}+NaCl} }$

The different solubilities of the salts make them easy to separate. The resulting sodium chloride can in turn be used as a starting product for the perchlorate cell.

Use in medicine

Perchlorate is a monovalent anion with an ion volume similar to that of iodide and pertechnetate (about 4 × 10 ⁻²³ cm ³ ); it competes with iodide on the sodium iodide symporter . Sodium perchlorate ( trade name Irenat ^® ) therefore competitively inhibits the uptake of iodine and also that of technetium in the thyroid gland . It was therefore previously used to treat hyperthyroidism . The only use of sodium perchlorate today is to block the thyroid gland when iodine-containing contrast media or thyroid-permeable radiopharmaceuticals ( ¹²³ I, ¹³¹ I, ^99m Tc) are administered in order to keep the radiation exposure of the thyroid low, unless the thyroid itself is to be exposed.

In the context of the perchlorate depletion test , sodium perchlorate is also used to diagnose disorders of iodine utilization.

Safety instructions / risk assessment

Sodium perchlorate is oxidizing. There is an acute risk of fire or explosion if it is contaminated or mixed with other substances. Toxic, aggressive vapors are formed during decomposition.

Sodium perchlorate was included in the EU's ongoing action plan ( CoRAP ) in 2015 in accordance with Regulation (EC) No. 1907/2006 (REACH) as part of substance evaluation . The effects of the substance on human health and the environment are re-evaluated and, if necessary, follow-up measures are initiated. Ingestion of sodium perchlorate was driven by concerns about worker exposure , other hazard-related concerns, and widespread use, and the potential hazard posed by carcinogenic properties and as a potential endocrine disruptor . The reassessment took place from 2015 and was carried out by Germany . A final report was then published. Sodium perchlorate was classified as an endocrine disruptor and a potential SVHC compound.

Individual evidence

1. ↑ ^{a b c d e} Entry on sodium perchlorate in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .
2. ↑ ^{a b} Data sheet sodium perchlorate monohydrate (PDF) from Merck , accessed on February 3, 2018.
3. ↑ Sodium perchlorate data sheet at Acros, accessed on February 3, 2018.
4. ↑ Dimethyl Sulfoxide (DMSO) Solubility Data. Gaylord Chemical Company, LLC; Bulletin 102, June 2014, p. 14. (PDF)
5. ↑ Entry on sodium perchlorate in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers and / or distributors can expand the harmonized classification and labeling .
6. ↑ Chase, MW, Jr .: NIST-JANAF Themochemical Tables , Fourth Edition, J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951.
7. ↑ Making Sodium Chlorate. Production of sodium perchlorate. Archived from the original on October 27, 2009 ; accessed on July 29, 2012 . 
8. ↑ R. Wartchow, HJ Barthold: Refinement of the crystal structure of sodium perchlorate NaClO ₄ . In: Zeitschrift für Kristallographie, Kristallgeometrie, Kristallphysik, Kristallchemie , 147, 1978, pp. 307-317, doi : 10.1524 / zkri.1978.147.14.307
9. ↑ HJ Berthold, BG Kruska, R. Wartchow: The crystal structure of the disordered cubic high-temperature phase of sodium perchlorate NaClO ₄ . In: Journal of Nature Research B . 34, 1979, pp. 522-523 ( online ).
10. ↑ ^{a b} Long, JR: Perchlorate safety: Reconciling inorganic and organic guidelines in Chem. Health Safety 9 (2002) 12-18, doi : 10.1016 / S1074-9098 (02) 00294-0 .
11. ↑ Willard, HH; Smith, GF: The Perchlorates of the Alkali and Alkaline Earth Metals and Ammonium. Their Solubility in Water and Other Solvents in J. Am. Chem. Soc. 45 (1923) 286-297, doi : 10.1021 / ja01655a004 .
12. ^ T. Kuwert. Thyroid. In: T. Kuwert, F. Grünwald, U. Haberkorn, T. Krause: Nuclear medicine. Stuttgart, New York 2008, ISBN 978-3-13-118504-4 .
13. ↑ Community rolling action plan ( CoRAP ) of the European Chemicals Agency (ECHA): sodium perchlorate , accessed on March 26, 2019.
14. ↑ European Chemicals Agency (ECHA): Substance Evaluation Conclusion and Evaluation Report .