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Hydriodic acid structure

CAS No. 10034-85-2 chemical Name: Hydriodic acid Synonyms Hydriodic;55-57 wt.%;caswellno482c;Hydrideiodine;hydrogenHydrogeniodid;Hydroidic acid;Jodwasserstoff;HYDRIODIC ACID;HYDRIOTIC mountain CBNumber: CB7852570 molecular Formula: hi Formula Weight: 127.91 MOL File: 10034-85-2.mol
melt point: -50.8° cook point: 127 °C(lit.) thickness 1.96 g/mL at 20 °C flash point: 126-127°C warehouse temp. 2-8°C pka -10(at 25℃) kind colorless or yellow gas shade Colorless come brown odor Pungent smell PH variety 1 Water Solubility soluble perceptible Hygroscopic Merck 14,4776 Stability: Stable. Incompatible through bases, amines. Corrodes steel. May discolour ~ above exposure to air and also light. Indirect Additives supplied in Food contact Substances HYDRIODIC acid CAS DataBase referral 10034-85-2(CAS DataBase Reference) EWG"s Food Scores 1 FDA UNII 694C0EFT9Q NIST Chemistry recommendation Hydrogen iodide(10034-85-2) EPA substance Registry mechanism Hydriodic mountain (10034-85-2)

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Hydriodic mountain Chemical Properties,Uses,Production


hydriodic acid is a solid acid. Chemistry Formula is HI. The molecular load is 127.91. Colorless gas, pale yellow fluid or blob solid. There is a solid pungent odor. Melting allude is-50.8 ℃, the boiling allude is-35.38 ℃, relative density is 5.660 (gas), 2.85-4.7 (liquid), the refractive index is 1.46616. And kind a white mountain mist through water vapor in the air, conveniently soluble in water and emit a many of warm to create Hydriodic acid. Slightly soluble in ethanol. Unstable, heated come decompose into hydrogen and also iodine under the light. Considerably decomposition over 300 ℃. Its constant boiling solution is colorless or irradiate yellow fuming liquid, boiling suggest is 127 ℃, relative thickness is 1.7015, strong acid (degree that dissociation of 0.1 mol·L-1 hydroiodic systems up to 95%), the solubility the Hydriodic mountain in an organic solvent is much smaller than in water, present in non-electrolytes or weak electrolytes, that ionization continuous in pyridine is 3 × 10-3. Easily break down into hydrogen and also iodine in the air. With a solid reduction, It has actually the strongest reducibility in hydrohalic acids, may be oxidated to cost-free iodine by Cl2, Br2, concentrated sulfuric acid. Oxidation by air at room temperature, can be oxidated by concentrated nitric acid, focused sulfuric acid. The reacts v most metals to form the corresponding iodide and also hydrogen. Method: by heater reaction of salt iodide and also phosphoric acid or reaction that phosphorus through iodine, water was added dropwise ~ above a mixture the phosphorus and iodine, can likewise be obtained by suspending iodine in water and ventilation with hydrogen sulfide. Its constant boiling solution is acquired by ventilating Hydriodic acid gas right into the water. Uses: its constant boiling solution is regularly used as a reducing agent, a disinfectant, analysis reagents, preparation of iodized salt, artificial drugs, dyes, perfumes and also so on. It is synthesized through iodine vapor and hydrogen under platinum catalytic problems or obtained by hydrolysis of phosphorus triiodide.The over information is edited by Yan Yanyong that

Chemical Properties

Hydroiodic acid is aqueous solution of Hydriodic acid. When fresh, the is colorless, quickly precipitates iodine with yellow to brown in air and also sunlight. Azeotrope (56.9% HI), the relative density is 1.70. Boiling point is 127 ℃. Items hydroiodic are divided into 3 types: 57% HI, relative density is 1.70. 47% HI, relative density is 1.5. 1% HI, relative density is 1.1. Add 1.5% hypophosphorous mountain to make it bleach. The an important temperature is 150 ℃: the an essential pressure is 8.3MPa. The dielectric continuous is 3.57 at-45 ℃. Conductivity is 8.5 × 10-10S · cm-1. Heat of vaporization is 19.76 Kj/mol, melting warm is 2.87 Kj/mol. Quickly soluble in water, dissolve in necessary solvents.Hydriodic mountain is offered as a catalyst in the to produce of acetic acid, together a pharmaceutical intermediate, in assorted disinfectant/sanitization formulations consisting of teat dips because that mastitis control, and also in the ready of organic and also inorganic iodides.

Production method

Slowly include iodine and also red phosphorus come a reactor filled v water, and react under stirring, filter the reaction solution, and distill the filtrate, collect fractions the 125~130 ℃, acquire Hydroiodic. 2P + 5I2 → 2PI5 PI5 + 4H2O → 5HI + H3PO4


it is extremely corrosive to many metals, Non-combustible. Yet it reaction violently through fluorine, potassium nitrate, potassium chlorate and so on. As hydrochloric acid, it has actually a strong irritation, gases or vapors deserve to irritate the eyes and respiratory system. Liquid have the right to burn the skin. The patient that inhaled vapors should automatically keep away from the contaminated area, put to rest and also keep warm. Coincidentally splashed into the eyes, rinse immediately with many of water because that 15min. Call with skin, wash instantly with many of water. Swallowed immediately rinse mouth, rushed to the hospital because that treatment.


1. Supplied for creating organic iodide. As basic reagents and pharmaceutical intermediates. 2. Used as the analysis reagents, also used in the ready of the iodide. 3. Supplied as a reduce agent, additionally used in the synthetic of alkyl iodine and also other alkyl iodide. 4. Offered for decision of methoxy, ethoxy and selenium, resolution of acid-insoluble inorganic substance, such together an alkaline planet metal sulfate and mercury iodide and also so on. Supplied as a reduce agent. Supplied for the preparation of iodide. 5. Offered for decision of methoxy, resolution of acid-insoluble (especially hot) not natural substance, such as an alkaline earth metal sulfate and also mercury iodide and so on. Provided as a reduce agent.


Compressed gas and liquefied gas.

Explosive hazardous characteristics

Contacting through alkali metals have the right to be explosive, thermal decomposition into toxic iodine vapor in the situation of heat, create toxic hydroiodic in the instance of water.

Flammability danger characteristics

flammability in case of N,N-dinitroso pentamethylene tetramine, release hydrogen cyanide gas in situation of cyanide toxic, thermal decomposition of toxic iodide gases.

Storage Characteristics

Treasury ventilation, low-temperature drying and also stored individually from cyanide, N,N-dinitroso pentamethylene tetramine, bases.

Extinguishing agent



‘Iodine’ is derived from iodes, a Greek word an interpretation violet. The isa member that the halide family and also hydrogen iodide isconsidered a strong acid.

Chemical Properties

Hydrogen iodide is a colourless come yellow/brown through an acrid odour non-flammable gas. Hydrogen iodide is incompatible with water and other halides. Hydrogen iodide, upon contact with moisture in air, releases dense vapours. Hydrogen iodide reacts v water to kind corrosive acids and reacts violently with alkalis. Most metals corrode swiftly on call with wet hydrogen iodide, and prolonged exposure that hydrogen iodide to fire or intense heat has been reported to cause the container to rupture and also rocket.

Physical properties

This is a strong acid, do by dissolving hi gas inwater. However, hydrogen iodide and hydroiodic aciddiffer in that the previous is a gas under traditional conditionswhereas the various other is an aqueous solution of saidgas. They space noninterconvertible. That is, when theacid is created with water, it cannot be recovered likeHCl or HBr. Hydroiodic acid is used in organic and inorganicsynthesis as one of the major sources that iodineand as a to reduce agent.With moist air, hi gas provides a mist (or fumes) ofhydroiodic acid. The is exceptionally dissolve in water.One liter that water will dissolve 425 l of HI, the finalsolution include only 4 water molecules every moleculeof HI. As stated, return chemically related,hydroiodic acid is not pure HI but a mixture comprise it. Advertisement “concentrated” hydroiodic mountain usuallycontains 90–98% hello by mass.


Hydriodic mountain is offered in the manufactureof iodides, together a to reduce agent, and also indisinfectants and pharmaceuticals.


reducing agent, produce of inorganic iodides, pharmaceuticals, disinfectants. The 57% acid is also used for analytical purposes, such together methoxyl determinations.


Hydriodic mountain (HI) is a colorless solution created when hydrogen iodide gas is dissolved in water, commercially of stamin 10% HI, frequently colored brown by iodine. There is a maximum consistent boiling allude 127 °C (774 mm) in ~ 57% hi (distillate) because that mixtures of hydriodic acid and water. Hydriodic mountain is provided in the ready of iodides, and also as crucial reagent in essential chemistry.


hydrogen iodide: A colourless gas,HI; m.p. –51°C; b.p. –35.38°C. That canbe do by direct combination ofthe elements using a platinum catalyst.It is a strong acid dissociating extensivelyin systems (hydroiodic mountain or hydriodic acid). That is also a reducingagent.


Hydrogen iodide is prepared by direct mix of hydrogen and also iodinevapor in the presence of platinum catalyst:H2 + I2 → 2HIThe link is produced in commercial scale by reaction the iodine withhydrazine or hydrogen sulfide:2I2 + N2H4 → 4HI + N2I2 + H2S → 2HI + SHydriodic acid might be all set by dissolving hydrogen iodide gas in water.The acid likewise may be obtained by electrolysis that iodine equipment or through passinghydrogen sulfide right into a suspension the iodine in water and also boiling to expelexcess sulfide. After boiling, the precipitation sulfur is removed by filtrationthrough fritted glass key or glass wool.Hydriodic acid in small quantities might be ready by including water care-fully come a solid mixture the red phosphorus and also iodine.Technical great hydriodic acid is a 47% hello solution and usually has actually abrown color due to the existence of totally free iodine, developed by air oxidation that HI.Hydriodic acid have to be save in the dark to protect against photochemical decom-position, and complimentary from wait to avoid oxidation. The addition of 1.5%hypophosphorus mountain (H3PO2) prevents oxidative decomposition.Hydriodic acid also is commercially marketed at 57% (azeotropic concentration)and 10% aqueous solutions.

General Description

A colorless come yellow liquid with a pungent odor. Is composed of a solution of hydrogen iodide in water. Fumes wake up the eyes and mucous membranes. Corrosive to metals and to tissue.It is prepared by the reaction that iodine and also hydrosulfuric mountain or through the reaction of phosphorus add to iodine to add water complied with by distillation. Focused hydroiodic acid reacts through the oxygen of the waiting to kind free iodine, which provides a brownish shade to the solution. It also gives one idea of the reducing nature of this acid. It is vital reagent in essential chemistry and is used commercially in the ready of iodides.

Air & Water Reactions

soluble in water v release the heat.

Reactivity Profile

HYDROIODIC acid reacts exothermically through organic bases (amines, amides) and also inorganic bases (oxides and also hydroxides the metals). Reacts exothermically through carbonates (including limestone and also building materials containing limestone) and also hydrogen carbonates to generate carbon dioxide. Reacts through sulfides, carbides, borides, and also phosphides to generate toxic or flammable gases. Reaction with many metals (including aluminum, zinc, calcium, magnesium, iron, tin and every one of the alkali metals) to create flammable hydrogen gas. Reacts violently through acetic anhydride, 2-aminoethanol, ammonium hydroxide, calcium phosphide, chlorosulfonic acid, 1,1-difluoroethylene, ethylenediamine, ethyleneimine, oleum, perchloric acid, b-propiolactone, propylene oxide, silver perchlorate/carbon tetrachloride mixture, salt hydroxide, uranium(IV) phosphide, vinyl acetate, calcium carbide, rubidium carbide, cesium acetylide, rubidium acetylide, magnesium boride, mercury(II) sulfate . Mixture with focused sulfuric acid deserve to evolve toxic hydrogen iodide gas in ~ a danger rate. Decomposes at high temperature to emit toxic products. Reacts through fluorine, dinitrogen trioxide, nitrogen dioxide/dinitrogen tetraoxide, and fuming nitric acid.


solid irritant. Poison.

Health Hazard

TOXIC; inhalation, gulp down or skin call with material may cause severe injury or death. Contact with molten substance may cause severe burns come skin and also eyes. Avoid any type of skin contact. Impacts of call or inhalation may be delayed. Fire may create irritating, corrosive and/or toxic gases. Runoff from fire regulate or dilution water might be corrosive and/or toxic and also cause pollution.

Health Hazard

Hydriodic acid is a corrosive liquid thatcan produce burns on contact with the skin.Contact that acid with the eyes deserve to causesevere irritation. The gas, hydrogen iodide, isa solid irritant to the eyes, skin, and mucousmembranes. No exposure limit has been setfor this gas.

Fire Hazard

Non-combustible, substance chin does no burn but may decompose upon heating to create corrosive and/or toxicity fumes. Some space oxidizers and also may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals might evolve flammable hydrogen gas. Containers may explode as soon as heated.

Purification Methods

Iodine can be eliminated from aqueous HI, most likely as the amine hydrogen triiodide, by three succeeding extractions making use of a 4% systems of Amberlite LA-2 (a long-chain aliphatic amine) in CCl4, toluene or pet ether (10mL per 100mL the acid). Extraction v tributyl phosphate in CHCl3 or various other organic solvents is also suitable. Alternatively, a De-acidite FF anion-exchange resin pillar in the OH--form utilizing 2M NaOH, then right into its I--form by passing dilute KI solution through, have the right to be used. I of an HI systems under CO2 with such a column clears polyiodide. The column can be regenerated v NaOH. . The earlier method was to reflux with red phosphorus and distil in a stream of N2. The colourless product is save in ampoules in the dark . The fumes in moist air. HARMFUL VAPOURS.

Toxicity evaluation

Hydroiodic acid is a solid irritant. When used as an expectorant,hydroiodic mountain is believed to act by irritating the gastricmucosa, which climate stimulates respiratory tract secretion.

Hydriodic acid Preparation Products and Raw materials

Raw materials