red powder(s); enthalpy of formation ?58.2 kJ/mol; entropy 213.0 J/(mol · K); enthalpy of vaporization 59.3 kJ/mol; decomposes slowly in air at 100°C, rapidly at 200°C, to give As, I2, As2O3; made by precipitation from a hot AsCl3-HCl solution by the addition of KI [KIR78] [STR93]
Formerly the compound was used in dermatitides.
Arsenic(III) iodide is useful for preparing organoarsenic compounds.
Arsenic triiodide is prepared by treating elemental arsenic with a solution of iodine in carbon disulfide. Alternatively, it can be precipitated out from a hot solution of arsenic trioxide or arsenic trisulfide in hydrochloric acid on treatment with potassium or sodium iodide. Also, it is made by the reaction of arsenic trichloride with potassium iodide.
Includes any unique chemical substance that contains arsenic as part of the infrastructure of that chemical.
Orange-red rhombohedral crystals (from acetone). Density 4.69 g / cm3. Melting point 285.6°F (140.9°C). Red as a liquid.
Reacts slowly with oxygen from the air, liberating iodine [Merck]. Water soluble. Aqueous solutions are strongly acidic (pH of 0.1N solution about 1.1) and ultimately form HI and As2O3, although an equilibrium AsI3 + 3H2O = H3AsO3 + 3HI has been observed [Merck 1989].
ARSENIC IODIDE gives acidic solutions in water. These solutions neutralize bases exothermically. Can react as either an oxidizing agent or reducing agent.
Highly toxic, may be fatal if inhaled, swallowed or absorbed through skin. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.
Combustible material: may burn but does not ignite readily. Containers may explode when heated. Runoff may pollute waterways. Substance may be transported in a molten form.
Inorganic compounds
are confirmed human carcinogens
producing tumors of the mouth, esophagus,
larynx, bladder, and paranasal sinus.
Recognized carcinogens of the skin, lungs,
and liver. Used as insecticides, herbicides,
silvicides, defoliants, desiccants, and
rodenticides. Poisoning from arsenic
compounds may be acute or chronic. Acute
poisoning usually results from swallowing
arsenic compounds; chronic poisoning from
either swallowing or inhaling. Acute allergic
reactions to arsenic compounds used in
medical therapy have been fairly common,
the type and severity of reaction depending
upon the compound. Inorganic arsenicals
are more toxic than organics. Trivalent is
more toxic than pentavalent. Acute arsenic
poisoning (from ingestion) results in marked
irritation of the stomach and intestines with
nausea, vomiting, and darrhea. In severe
cases, the vomitus and stools are bloody and
the patient goes into collapse and shock
with weak, rapid pulse, cold sweats, coma,
and death. Chronic arsenic poisoning,
whether through ingestion or inhalation,
may manifest itself in many different ways.
There may be disturbances of the digestive
system such as loss of appetite, cramps,
nausea, constipation, or diarrhea. Liver
damage may occur, resulting in jaundice.
Disturbances of the blood, kidneys, and
nervous system are not infrequent. Arsenic
can cause a variety of skin abnormalities
including itching, pigmentation, and even
cancerous changes. A characteristic of
arsenic poisoning is the great variety of
sympt-oms that can be produced.
Dangerous; when heated to decomposition,
or when metallic arsenic contacts acids or
acid fumes, or when water solutions of
arsenicals are in contact with active metals
such as Fe, Al, or Zn, highly toxic fumes of
arsenic are emitted.
It crystallises from acetone and sublimes below 100o. It is very slowly hydrolysed by H2O (much more slowly than the chloride). POISONOUS. [Schenk in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol I p 597-598 1963.]
