Sodium iodide

Sodium iodide ;
Names:	sodium iodide; sodium jodide PubChem: 5238; CAS: 7681-82-5; InChI Key: FVAUCKIRQBBSSJ-UHFFFAOYSA-M;
Formula:	NaI;
SMILES:	[Na+].[I-];
Molar mass:	149.890 g/mol;
Density:	3.665 g/cm3;
Crystal system:	cubic; a=3.24 Å, b=3.24 Å, c=3.24 Åα=90°, β=90°, γ=90°;
Shapes:	https://en.crystalls.info/w/uploads/media/3/30/Tetragonal_flat_prism.json Tetragonal flat prism https://en.crystalls.info/w/uploads/media/a/af/Tetragonal_prism.json Tetragonal prism ;
Color:	colorless;
Melting point:	662 °C935.15 K <br />1,223.6 °F <br />1,683.27 °R <br />;
Boiling point:	1304 °C1,577.15 K <br />2,379.2 °F <br />2,838.87 °R <br />;
Refractive index:	1.7745 ;
Magnetic properties:	diamagnetic; χ=-5.70 · 10-5cm³/mol;
Radiation properties:	scintillator;
Stability:	slightly hygroscopic;
Hardness:	strong;
Toxicity:	non-toxic; LD50=4340mg/kg

Description

Inorganic compound, salt of alkaline metal sodium and inorganic hydroiodic acid. Doesn't form water hydrates.

Precursors

Reaction between iodine, sodium hydroxide and hydrogen peroxide

Chemical equation:

2NaOH + I₂ + H₂O₂ = 2NaI + 2H₂O + O₂↑

For preparation of 100.00g of sodium iodide а 26.68g of hydroxide, 378.21g of

3%3%
30%

peroxide and 84.66g of iodine is required.

Add to the flask with hydroxide solution hydrogen peroxide and then add small parts of iodine with stirring until oxide emission will stop. For purifying compound from hydroxide add large amount of cold ethanol, acetone or toluene to solution, salt will settle to the bottom in the form of fine crystals or powder. Filter precipitate and wash it with small amount of the same solvent, then filter the solution and use it for crystal growing.

Reaction between sodium hydroxide or carbonate фтв hydroiodic acid

Chemical equation:

NaOH + HI = NaI + H₂O

Na₂CO₃ + 2HI = 2NaI + H₂O + CO₂↑

For preparation of 100.00g of sodium iodide а 26.68g of hydroxide or 35.36g of carbonate and 149.71g of 57%57% hydrobromic acid is required.

Add acid to the flask, then add small parts of sodium compound with stirring until heating will stop (attention, the solution may boil!) or, if you use carbonate, until carbon dioxide emission will stop.

Influence of temperature

Dissolving is endothermic, solution cools much, so use hot water or using heat.
Rapid cooling causes prismatic crystals growth.

Influence of impurities

Excess of iodine causes reddening of solution, excess of potassium hydroxide causes slowing down crystal growth or finally stops it.

Notes

Reacts with humid air with forming iodine at the crystal surface, so crystals becomes more dark-colored.
Too big solubility in water is intervenes growing process, so using organic solvents should be preferred.

Storage conditions

Store in its original form or under several layers of varnish at average humidity and room temperature. Do not store in matchboxes or cotton wool and do not heat.

Solubility

TableGraph

Temperature	гр/`100,00` гр water	гр/`100,00` гр ethanol	гр/`100,00` гр methanol	гр/`100,00` гр acetone	гр/`100,00` гр DMSO	гр/`100,00` гр furfural	гр/`100,00` гр formic acid	гр/`100,00` гр propanol	гр/`100,00` гр 2-butanone	гр/`100,00` гр ammonia	гр/`100,00` гр hydrazine	гр/`100,00` гр ethylenediamine	гр/`100,00` гр acetamide	гр/`100,00` гр dimethylformamide	гр/`100,00` гр N-methylformamide	гр/`100,00` гр nitromethane	гр/`100,00` гр acetonitrile	гр/`100,00` гр propionitrile	гр/`100,00` гр allyl alcohol	гр/`100,00` гр amyl alcohol	гр/`100,00` гр benzyl alcohol
0°C273.15 K <br />32 °F <br />491.67 °R <br />	`158.7`			`13.1`						`131.9`						`0.3`	`28.32`	`11.6`
10°C283.15 K <br />50 °F <br />509.67 °R <br />	`167`		`65`	`~21.6`
15°C288.15 K <br />59 °F <br />518.67 °R <br />	`~173`		`~68.9`	`~25.8`
20°C293.15 K <br />68 °F <br />527.67 °R <br />	`179.3`	`46`	`72.7`	`30`			`62.71`		`15`		`61`
25°C298.15 K <br />77 °F <br />536.67 °R <br />	`184.2`	`43.3`	`78`	`39.9`	`30`	`21.6`	`61.81`	`28.22`		`146.3`		`34.6`		`14.4`	`61`	`0.42`	`23.63`	`7.96`	`28.49`	`16.3`	`14.4`
30°C303.15 K <br />86 °F <br />545.67 °R <br />	`190`		`~78.9`	`~38.5`
40°C313.15 K <br />104 °F <br />563.67 °R <br />	`205`		`80.7`	`~35.6`
50°C323.15 K <br />122 °F <br />581.67 °R <br />	`227.8`		`~80.1`	`~32.8`					`8.9`
60°C333.15 K <br />140 °F <br />599.67 °R <br />	`257`		`79.4`	`29.9`
70°C343.15 K <br />158 °F <br />617.67 °R <br />	`294`			`~25.9`
80°C353.15 K <br />176 °F <br />635.67 °R <br />	`295`			`21.8`									`5.62`
90°C363.15 K <br />194 °F <br />653.67 °R <br />	`~299`
100°C373.15 K <br />212 °F <br />671.67 °R <br />	`302`

Highly soluble in glycerol. Soluble in pyridine. Insoluble in isopropanol.

Gallery

Growing with rapid solution cooling methodSodium iodide, Maxim Martinov, VKontakteMaxim MartinovVKontakte
Growing with rapid solution cooling methodSodium iodide, Maxim Martinov, VKontakteMaxim MartinovVKontakte
Sodium iodideChemlegin, BlogChemleginBlog

Sources

Navigation

Iodides
Salts	Germanium iodide (GeI₄) • Cadmium iodide (CdI₂) • Lead(II) iodide (PbI₂) • Potassium iodide (KI) • Sodium iodide (NaI) • Tin(II) iodide (SnI₂)
Complexes	Potassium tetraiodobismuthate (К[BiI₄]) • Potassium tetraiodomercurate(II) (K₂[HgI₄])

Sodium compounds
Salts	Sodium acetate (NaCH₃COO) • Sodium bromide (NaBr) • Sodium citrate (Na₃C₃H₅O(COO)₃) • Sodium chlorate (NaClO₃) • Sodium chloride (NaCl) • Sodium cyclamate (C₆H₁₂NNaO₃S) • Sodium decavanadate (Na₆V₁₀O₂₈) • Sodium ethilate (NaC₂H₅O) • Sodium glutamate (NaC₅H₈NO₄) • Sodium hydrocarbonate (NaHCO₃) • Sodium hydrosulfate (NaHSO₄) • Sodium iodide (NaI) • Sodium metavanadate (NaVO₃) • Sodium niobate (NaNbO₃) • Sodium nitrate (NaNO₃) • Sodium oxalate (Na₂C₂O₄) • Sodium para-aminosalicylate (C₇H₆NNaO₃) • Sodium perchlorate (NaClO₄) • Sodium saccharinate (C₇H₄NaNO₃S) • Sodium sulfate (Na₂SO₄) • Sodium sulfide (Na₂S) • Sodium tetraborate (Na₂B₄O₇) • Sodium thiosulfate (Na₂S₂O₃) • Sodium trichloracetate (NaCCl₃COO) • Sodium trioxalatoaluminate (Na₃[Al(C₂O₄)₃]) • Sodium tungstate (Na₂WO₄)
Double salts	Potassium-sodium tartrate (KNaC₄H₄O₆) • Sodium-ammonium sulfate (NaNH₄SO₄) • Uranyl-sodium acetate (NaUО2(CH₃COO)₃) • Uranyl-zinc-sodium acetate (NaZn(UO₂)₃(CH₃COO)₉) • Zinc-sodium sulfate (Na₂Zn(SO₄)₂)
Adducts	Glucose and sodium bromide complex (2C₆H₁₂O₆ · NaBr) • Glucose and sodium chloride complex (2C₆H₁₂O₆ · NaCl) • Urea and sodium chloride complex (CO(NH₄)₂ · NaCl)
Complex compounds	Sodium dicarbonatocuprate(II) (Na₂[Cu(CO₃)₂]) • Sodium dioxalatocuprate(II) (Na₂[Cu(C₂O₄)₂]) • Sodium ethylenediaminetetraacetate-ferrate(III) (Na[Fe((OOCCH₂)₂N(CH₂)₂N(CH₂COO)₂)]) • Sodium hexacyanoferrate(II) (Na₄[Fe(CN)₆]) • Tripotassium-sodium hexacyanoferrate(II) (K₃Na[Fe(CN)₆]) • Sodium hexafluorosilicate (Na₂[SiF₆]) • Sodium nitroprusside (Na₂[Fe(CN)₅NO]) • Sodium trioxalatochromate(III) (Ns₃[Cr(C₂O₄)₃]) • Dipotassium-sodium trioxalatoferrate(III) (K₂Na[Fe(C₂O₄)₃]) • Potassium-sodium trioxalatoferrate(III) (K₅Na[Fe(C₂O₄)₃]₂) • Sodium trioxalatoferrate(III) (Na₃[Fe(C₂O₄)₃])

Sodium iodide
Names:	sodium iodide sodium jodide PubChem: 5238 CAS: 7681-82-5 InChI Key: FVAUCKIRQBBSSJ-UHFFFAOYSA-M
Formula:	NaI
SMILES:	[Na+].[I-]
Molar mass:	149.890 g/mol
Density:	3.665 g/cm³
Crystal system:	cubic a=3.24 Å, b=3.24 Å, c=3.24 Åα=90°, β=90°, γ=90°
Shapes:	Tetragonal flat prism Tetragonal prism
Color:	colorless
Melting point:	662 °C935.15 K <br />1,223.6 °F <br />1,683.27 °R <br />
Boiling point:	1304 °C1,577.15 K <br />2,379.2 °F <br />2,838.87 °R <br />
Refractive index:	1.7745
Magnetic properties:	diamagnetic χ=-5.70 · 10^-5cm³/mol
Radiation properties:	scintillator
Stability:	slightly hygroscopic
Hardness:	strong
Toxicity:	non-toxic LD₅₀=4340mg/kg