Sodium iodide [131I] (Natrii iodidum [131I])

Sodium iodide Scintillators NaI (Tl)Identifiers Number of CAS

• 7681-82-5 Y
• 13517-06-1 (dihydrate) N

3D model (JSmol)

• Interactive image

CHEBY

• CHEBI: 33167 Y

CHAMBL

• ChEMBL1644695 N

ChemSpider

• 5048 Y

ECHA InfoCard100.028.800 PubChem CID

• 5238

RTECS number

• WB6475000

UNII

• F5WR8N145C Y

CompTox Dashboard (EPA)

• DTXSID2041125

InCHI

• InChI = 1S / HI.Na / h1H; /q; +1/p-1Y

  Key: FVAUCKIRQBBSSJ-UHFFFAOYSA-M Y

• InChI = 1/HI.Na/h1H; /q; +1/p-1

  Key: FVAUCKIRQBBSSJ-REWHXWOFAL

Smiles

• . [I-]

Characteristics Chemical formula NaI Molar mass 149.894 [1] Appearance white solid, soluble in air [1] Odor odorless Density 3.67 g cm−3 [1] Melting point 661 °C (1222 °F, 934 K) [1] Boiling point 1304 °C ( 2379 °F, 1577 K) [1] Water solubility 1587 g/l (0 °C) 1842 g/l (25 °C) 2278 g/l (50 °C) 2940 g/l (70 °C) 3020 g / l (100 ° C) [2] [3] Solubility ethanol, acetone [1] Band gap 5.89 eV [4] [5] Magnetic susceptibility (χ)−57 × 10 −6 cm 3 mol −1 [6] Refractive index ( n

D)

1.93 (300 nm) 1.774 (589 nm) 1.71 (10 µm) [7] Structure [8] Crystal structure Halite, cF8 Space group Fm 3 m, No. 225 Lattice constant A

= 0.6462 nm

Unit formula ( Z

)

4 Coordination geometry Octahedral Thermochemistry [9] Heat capacity ( C

)

52.1 J mol −1 K −1 Standard molar entropy ( S

o 298)

98.5 J mol −1 K −1 Std formation enthalpy (Δ F H

⦵ 298 )

−287.8 kJ mol −1 Gibbs free energy (Δ f G

˚)

−286.1 kJ mol −1 HazardsPrincipal HazardsIrritating, may harm the unborn child Safety Data Sheet[1]GHS PictogramsGHS Signal WordDanger Hazard statements GHSH315, H319, H400 Precautionary statements GHSP273, P305 + 351 + 338 [10]NFPA 704 (fire diamond) 1

0

1

flash point Non-flammable Related compounds Other anions Sodium fluoride Sodium chloride Sodium bromide Sodium astatide Other cations Lithium iodide Potassium iodide Rubidium iodide Cesium iodide France iodide Unless otherwise stated, data are for materials in their standard state (at 25 °C [77 °F], 100 kPa) .N check (what is there?)YNLinks to infoboxes

Sodium iodide

(chemical formula
NaI
) is an ionic compound formed from the chemical reaction of the metal sodium and iodine. Under standard conditions, it is a white, water-soluble solid containing a 1:1 mixture of sodium cations (Na + ) and iodide anions (I - ) in a crystal lattice. It is used primarily as a food additive and in organic chemistry. It is produced industrially as a salt formed by the reaction of acid iodides with sodium hydroxide.[11] It is a chaotropic salt.

Uses [edit]

Dietary supplement[edit]

Sodium iodide as well as potassium iodide are commonly used to treat and prevent iodine deficiency. Iodized table salt contains 10 ppm iodide. [eleven]

Organic synthesis[edit]

Monoatomic NaI chains grown inside double carbon nanotubes. [12]

Sodium iodide is used to convert alkyl chlorides to alkyl iodides. This method, the Finkelstein reaction,[13] relies on the insolubility of sodium chloride in acetone, which drives the reaction:[14]

R – Cl + NaI → R – I + NaCl

Nuclear medicine[edit]

Some radioactive sodium iodide salts, including Na125I and Na131I, have radiopharmaceutical uses, such as in the treatment of thyroid cancer and hyperthyroidism or as radiolabeled tracers in imaging (see Isotopes of Iodine > Radioiodine I-123 , I-124, I-125 and I-131 in medicine and biology).

NaI (Tl) scintillators doped with thallium[edit]

Sodium iodide is activated with thallium, NaI (Tl), when exposed to ionizing radiation emits photons (i.e. scintillation) and is used in scintillation detectors, traditionally in nuclear medicine, geophysics, nuclear physics and environmental measurements. NaI (Tl) is the most widely used scintillation material. The crystals are usually coupled to a photomultiplier tube in a sealed assembly because sodium iodide is hygroscopic. Fine tuning of some parameters (for example, radiation resistance, afterglow, transparency) can be achieved by varying the crystal growth conditions. Crystals with higher doping levels are used in X-ray detectors with high spectrometric quality. For this purpose, sodium iodide can be used either as single crystals or as polycrystals. The maximum emission wavelength is 415 nm. [15]

Sodium iodide

1. General information.

Formula:

NaJ

Sodium iodide NaI.

Colorless transparent crystals. It dissolves well in water and alcohol. There are a number of crystalline hydrates (NaJ.2H2O, NaJ.5H2O, etc.) and polyiodides NaI3 and NaI5. The molar electrical conductivity at infinite dilution at 25°C is 126.9 S.cm2/mol [4].

-288.06 kJ/mol;

-284.84 kJ/mol;

98.6 J/mol.K [3].

Boiling point: 1300 ºC

Melting point: 651° C

Density: 3.66

Solubility in water, g/100 ml at 20°C: 179.320

1. Receipt.

Sodium iodide (sodium iodide) is obtained by reacting I2 or an iodine-air mixture with sodium hydroxide solutions, followed by reduction of the resulting NaIO3 with hydrogen sulfide, hydrogen peroxide, or others, or by reacting sodium hydroxide, soda or sodium sulfate with hydroiodic acid.

1. Qualitative analysis.

1. Analytical reactions for sodium cation.

1. Reaction with zinc dioxouran(VI) acetate Zn(UO 2 ) 3 (CH 3 COO) 8

with the formation of a yellow crystalline precipitate (pharmacopoeial reaction - GF) or yellow crystals of tetrahedral and octahedral shape, insoluble in acetic acid (MCA). To increase the sensitivity of the reaction, the test mixture should be heated on a glass slide.

NaCl

+ Zn(UO2)3(CH3COO)8 + CH3COOH + 9 H2O

NaZn(UO2)3(CH3COO)9 9 H2O + HCl

Interfering ions: excess K+ ions, heavy metal cations (Hg22+, Hg2+, Sn2+, Sb3+, Bi3+, Fe3+, etc.). The reaction is used as a fractional reaction after removing interfering cations.

2. Coloring the colorless burner flame yellow (YF).

3. Reaction with picric acid to form yellow, needle-shaped sodium picrate crystals emanating from one point (ISS).

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The reaction is used as a fractional reaction only in the absence of interfering ions (K+, NH4+, Ag+).

4. Reaction with potassium hexahydroxostibate(V) K[Sb(OH) 6 ]

with the formation of a white crystalline precipitate, soluble in alkalis.

NaCl

+ K[Sb(OH)6] Na[Sb(OH)6] + KCl

Reaction conditions: a) sufficient concentration of Na+; b) neutral reaction of the solution; c) carrying out the reaction in the cold; d) rubbing a glass rod against the wall of the test tube. Interfering ions: NH4+, Mg2+, etc.

In an acidic environment, the reagent is destroyed with the formation of a white amorphous precipitate of metaantimony acid HSbO3.

K[Sb(OH)6] + HCl KCl + H3SbO4 + 2 H2O

H3SbO4 HSbO3 + H2O

3.2. Analytical reactions for iodide ion.

1. With a group reagent - AgNO3(GF) solution.

Methodology:

to 2 drops of iodide solution acidified with nitric acid, add 1-2 drops of silver nitrate solution, a yellow cheesy precipitate is formed, insoluble in ammonia solution and diluted HNO3.

2. With iron(III) chloride or sodium nitrite in an acidic medium (extraction method) (GF).

2 I—

+ 2 Fe3+ I2 + 2 Fe2+

2 I—

+ 2 NO2- + 4 H+ I2 + 2 NO + 2 H2O

Methodology:

To 2-3 drops of a solution containing iodide ions, add 1-2 drops of dilute sulfuric acid, 0.5 cm3 of chloroform, 2-3 drops of a solution of iron(III) chloride or sodium nitrite, shake vigorously. The chloroform layer turns pinkish-violet. When starch solution is added, a blue color appears.

NOTE: The detection of iodide ions with iron(III) chloride is interfered with by thiocyanate and acetate ions.

Sodium nitrite can be used to open iodide ions using the drop method:

Methodology:

1 drop of solutions of starch, 2 mol/dm3 CH3COOH, iodide and KNO2 is applied successively to the filter paper. A blue spot or ring is observed.

The reaction with sodium nitrite in an acidic environment is specific and makes it possible to detect iodide ions in the presence of chloride, bromide, and acetate ions.

3. With concentrated sulfuric acid (HF).

2 HI

+ H2SO4(conc.) I2 + SO2 + 2 H2O

Methodology:

When 0.1 g of a substance is heated with 1 cm3 of concentrated H2SO4, violet iodine vapor is released.

4. With chloramine B (chlorine water) with the release of molecular iodine.

5. With lead(II) salts to form a yellow precipitate.

2 I

— + Pb2+ PbI2

1. Quantitative analysis.

3.1. Argentometry.

Determination of the mass fraction of sodium iodide in a solution using the Faience argentometric method (direct titration option)

The determination is based on the precipitation of iodide ions with a solution of silver nitrate in acetic acid in the presence of the adsorption indicator eosin.

1. K I
+ AgNO 3  Ag I  + KNO 3
2. {(Ag I ) n
n I - (nx) K} x-

xK +
3. [(AgI) n ] 

4. {(AgI) n
nAg + (nx) NO 3 - } x+

x NO 3
-

at the end point of the titration:

5. {(Ag I ) n
nAg + (nx) Jnd - } x+

x NO 3 -
M (KI) = 166.01 g/mol

M (NaI) = 149.89 g/mol

Methodology:

The exact volume of potassium iodide solution (individual assignment) is placed in a titration flask, 2-3 drops of eosin indicator solution, 10 drops of diluted (30%) acetic acid are added and titrated with 0.05 M silver nitrate solution until the precipitate turns bright pink. .

1. Application.

Sodium iodide (Sodium iodide) is used • for the production of single crystals, • in the pharmaceutical industry and medicine, • in veterinary medicine and agriculture, • as a scintillator, an electrolyte component in chemical current sources and electrochemical converters, etc.

1. Bibliography.

1. Lurie Yu.Yu. Handbook of Analytical Chemistry. Moscow, 1972;
2. Methodological instructions “Instrumental methods of analysis”, Perm, 2004;
3. Methodological instructions “Qualitative chemical analysis”, Perm, 2003;
4. Methodological instructions “Quantitative chemical analysis”, Perm, 2004;
5. Rabinovich V.A., Khavin Z.Ya. Brief chemical reference book, Leningrad, 1991;
6. "Great Soviet Encyclopedia";
7. https://ru.wikipedia.org/.

Solubility data[edit]

Sodium iodide is highly soluble in some organic solvents, unlike sodium chloride or even sodium bromide:

Solvent	Solubility of NaI (g NaI/kg solvent at 25 °C) [16]
H2O	1842
Liquid ammonia	1620
Liquid sulfur dioxide	150
Methanol	625–830
Formic acid	618
Acetonitrile	249
Acetone	504
Formamide	570–850
Acetamide	323 (41.5 °C)
Dimethylformamide	37–64
Dichloromethane	0,09 [17]

Use and application

About 2/3 of all iodine and its compounds are used in sanitation systems or in the production of various antiseptics and medicines. The substance is also used to make dyes, photographic film and special soaps. It is used in some industries as a catalyst, a substance used to speed up or slow down a chemical reaction. It does not undergo any changes during the reaction.

An element can have both beneficial and unfavorable effects on living organisms. It tends to kill bacteria and other disease-causing organisms. This property of the substance leads to its use in sanitation systems and as an antiseptic, a chemical that stops the growth of microbes.

Tincture of iodine has always been one of the most popular antiseptic drugs. It was applied to cuts and wounds to prevent infection. Today it is often replaced by other antiseptics.

One of the reasons that tincture is used less frequently today is that it can also cause problems. In higher doses, iodine can irritate or burn the skin. It can also be quite poisonous if taken orally, so it is important to use it as directed.

Other important uses of iodine are:

• Because it is converted to thyroxine in the thyroid gland, small amounts are essential for the body, which contains an average of 14 mg (0.00049 oz) of the element. Thyroxine is a hormone necessary to maintain normal metabolism in all cells of the body. It is capable of stimulating the nervous system, especially the cerebral cortex and diencephalon. In many places, drinking water contains enough iodine for this purpose.
• The element and its compounds are widely used in analytical chemistry. Many procedures are based on the release or absorption of iodine and its subsequent titration with sodium thiosulfate (iodometry). The unsaturation of fats (that is, the number of double or triple bonds between carbon atoms) is determined by the addition of free iodine (iodine value).
• Used in photography as silver iodide and potassium iodide.
• Silver iodide is also used to plant clouds to cause rain.
• Used in the production of dyes.

Links[edit]

1. ^ B s d e e Haynes, pp. 4.86
2. Seidell, Atherton (1919). Solubility of inorganic and organic compounds c. 2. D. Van Nostrand Company. paragraph 655.
3. Jump up
   ↑ Haynes, p. 5.171
4. Miyata, Takeo (1969). "Exciton structure of NaI and NaBr". Journal of the Physical Society of Japan
   .
   27
   (1): 266. Bibcode: 1969JPSJ ... 27..266M. DOI: 10.1143/JPSJ.27.266.
5. Guizzetti, G.; Nosenzo, L.; Reguzzoni, E. (1977). "Optical properties and electronic structure of alkali metal halides by thermal reflection." Physical Review
   B.
   15
   (12):5921–5926. Bibcode: 1977PhRvB..15.5921G. DOI: 10.1103/PhysRevB.15.5921.
6. Jump up
   ↑ Haynes, p. 4,130
7. Jump up
   ↑ Haynes, p. 10,250
8. Davey, Wheeler P. (1923). "Precision measurements of alkali metal halide crystals". Physical Review
   .
   21
   (2): 143–161. Authorization code: 1923PhRv…21..143D. DOI: 10.1103/PhysRev.21.143.
9. Jump up
   ↑ Haynes, p. 5.36
10. "Sodium iodide 383112". Sigma Aldrich
    .
11. ^ab Lyday, Phyllis A. (2005). "Iodine and iodine compounds". Ullman Encyclopedia of Industrial Chemistry
    . Weinheim: Wiley-VCH. pp. 382–390. DOI: 10.1002/14356007.a14_381.
12. Senga, Ryosuke; Suenaga, Kazu (2015). "Spectroscopy of monatomic electron energy loss of light elements". Nature Communications
    .
    6
    : 7943. Bibcode: 2015NatCo... 6.7943S. DOI: 10.1038/ncomms8943. PMC 4532884. PMID 26228378.
13. Finkelstein, Hank (1910). "Darstellung organischer Jodide aus den entsprechenden Bromiden und Chloriden". Ber. Dtsch. Chem. Ges.
    (German).
    43
    (2):1528–1532. DOI: 10.1002/cber.19100430257.
14. Streitwieser, Andrew (1956). "Solvolytic displacement reactions on saturated carbon atoms". Chemical Reviews
    .
    56
    (4):571–752. DOI: 10.1021/cr50010a001.
15. "Scintillation Materials and Assemblies" (PDF). Crystals of Saint-Gobain. 2016. Retrieved June 21, 2022.
16. Burgess, John (1978). Metal ions in solution
    . Ellis Horwood Series in Chemical Sciences. New York: Ellis Horwood. ISBN 9780470262931.
17. De Namor, Angela F. Danil; Traboulssi, Rafik; Salazar, Franz Fernandez; De Acosta, Vilma Dianderas; De Viscardo, Iboni Fernandez; Portugal, Jaime Muñoz (1989). "Transfer and distribution of free energies of 1:1 electrolytes in the solvent system water - dichloromethane at 298.15 K." Journal of the Chemical Society, Proceedings of Faraday 1
    .
    85
    (9):2705–2712. DOI: 10.1039/F19898502705.

History of discovery

Iodine was discovered in 1811 by the French chemist Bernard Courtois (1777-1838). One of his first jobs in the early 1800s was to help his father make sodium and potassium compounds (potassium nitrate, KNO3) from seaweed.

Courtois and his father collected seaweed on the coasts of Normandy and Brittany in France. They then burned them and soaked the algae ashes in water to dissolve the sodium and potassium compounds. One day in 1811, Bernard added sulfuric acid and saw violet vapors that condensed, forming crystals with a metallic luster. Courtois guessed that it was a new element, which he named after its color (in Greek, the word "iodes" means "purple").

Courtois gave a small amount of this substance to Charles-Bernard Desormes and Nicolas Clément, who carried out a systematic investigation. In November 1813 they exhibited iodine at the Imperial Institute in Paris. That this was indeed a new element was proven by Joseph Gay-Lussac and confirmed by Humphry Davy, who sent a report to the Royal Institution in London, which incorrectly assumed that he was the discoverer, a belief that persisted for over 50 years.