Names | |
---|---|
Other names
| |
Identifiers | |
| |
3D model (JSmol) | |
ChemSpider | |
ECHA InfoCard | 100.030.704 |
EC Number |
|
PubChem CID | |
RTECS number |
|
UNII |
|
UN number | 1564 |
CompTox Dashboard (EPA) | |
| |
| |
Properties | |
BaCl2 | |
Molar mass | 208.23 g/mol (anhydrous) 244.26 g/mol (dihydrate) |
Appearance | White powder, or colourless or white crystals (anhydrous) Colourless rhomboidal crystals (dihydrate) [2] [3] |
Odor | Odourless |
Density | 3.856 g/cm3 (anhydrous) 3.0979 g/cm3 (dihydrate) |
Melting point | 962 °C (1,764 °F; 1,235 K) (960 °C, dihydrate) |
Boiling point | 1,560 °C (2,840 °F; 1,830 K) |
| |
Solubility | Soluble in methanol, insoluble ethyl acetate, slightly soluble in hydrochloric acid and nitric acid, very slightly soluble in ethanol. [4] [3] The dihydrate of barium chloride is soluble in methanol, almost insoluble in ethanol, acetone and ethyl acetate. [3] |
−72.6·10−6 cm3/mol | |
Structure | |
PbCl2-type orthorhombic (anhydrous) monoclinic (dihydrate) | |
Thermochemistry | |
Std molar entropy (S⦵298) | 123.9 J/(mol·K) |
Std enthalpy of formation (ΔfH⦵298) | −858.56 kJ/mol |
Hazards | |
Occupational safety and health (OHS/OSH): | |
Main hazards | Highly toxic, corrosive |
GHS labelling: | |
Danger | |
H301, H302, H332 | |
P261, P264, P270, P271, P301+P310, P304+P312, P304+P340, P312, P321, P330, P405, P501 | |
NFPA 704 (fire diamond) | |
Flash point | Non-flammable |
Lethal dose or concentration (LD, LC): | |
LD50 (median dose) | 78 mg/kg (rat, oral) 50 mg/kg (guinea pig, oral) [5] |
LDLo (lowest published) | 112 mg/kg (as Ba) (rabbit, oral) 59 mg/kg (as Ba) (dog, oral) 46 mg/kg (as Ba) (mouse, oral) [5] |
NIOSH (US health exposure limits): | |
PEL (Permissible) | TWA 0.5 mg/m3 [6] |
REL (Recommended) | TWA 0.5 mg/m3 [6] |
IDLH (Immediate danger) | 50 mg/m3 [6] |
Safety data sheet (SDS) | NIH BaCl |
Related compounds | |
Other anions | |
Other cations | |
Supplementary data page | |
Barium chloride (data page) | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Barium chloride is an inorganic compound with the formula Ba Cl 2. It is one of the most common water-soluble salts of barium. Like most other water-soluble barium salts, it is a white powder, highly toxic, and imparts a yellow-green coloration to a flame. It is also hygroscopic, converting to the dihydrate BaCl2·2H2O, which are colourless crystals with a bitter salty taste. It has limited use in the laboratory and industry. [7] [3]
On an industrial scale, barium chloride is prepared via a two step process from barite (barium sulfate). [8] The first step requires high temperatures.
The second step requires reaction between barium sulfide and hydrogen chloride:
or between barium sulfide and calcium chloride:
In place of HCl, chlorine can be used. [7] Barium chloride is extracted out from the mixture with water. From water solutions of barium chloride, its dihydrate (BaCl2·2H2O) can be crystallized as colorless crystals. [2]
Barium chloride can in principle be prepared by the reaction between barium hydroxide or barium carbonate with hydrogen chloride. These basic salts react with hydrochloric acid to give hydrated barium chloride.
BaCl2 crystallizes in two forms (polymorphs). At room temperature, the compound is stable in the orthorhombic cotunnite (PbCl2) structure, whereas the cubic fluorite structure (CaF2) is stable between 925 and 963 °C. [9] Both polymorphs accommodate the preference of the large Ba2+ ion for coordination numbers greater than six. [10] The coordination of Ba2+ is 8 in the fluorite structure [11] and 9 in the cotunnite structure. [12] When cotunnite-structure BaCl2 is subjected to pressures of 7–10 GPa, it transforms to a third structure, a monoclinic post-cotunnite phase. The coordination number of Ba2+ increases from 9 to 10. [13]
In aqueous solution BaCl2 behaves as a simple salt; in water it is a 1:2 electrolyte[ clarification needed ] and the solution exhibits a neutral pH. Its solutions react with sulfate ion to produce a thick white solid precipitate of barium sulfate.
This precipitation reaction is used in chlor-alkali plants to control the sulfate concentration in the feed brine for electrolysis.
Oxalate effects a similar reaction:
When it is mixed with sodium hydroxide, it gives barium hydroxide, which is moderately soluble in water.
BaCl2·2H2O is stable in the air at room temperature, but loses one water of crystallization above 55 °C (131 °F), becoming BaCl2·H2O, and becomes anhydrous above 121 °C (250 °F). [2] BaCl2·H2O may be formed by shaking the dihydrate with methanol. [3]
BaCl2 readily forms eutectics with alkali metal chlorides. [3]
Although inexpensive, barium chloride finds limited applications in the laboratory and industry.
Its main laboratory use is as a reagent for the gravimetric determination of sulfates. The sulfate compound being analyzed is dissolved in water and hydrochloric acid is added. When barium chloride solution is added, the sulfate present precipitates as barium sulfate, which is then filtered through ashless filter paper. The paper is burned off in a muffle furnace, the resulting barium sulfate is weighed, and the purity of the sulfate compound is thus calculated.
In industry, barium chloride is mainly used in the purification of brine solution in caustic chlorine plants and also in the manufacture of heat treatment salts, case hardening of steel. [7] It is also used to make red pigments such as Lithol red and Red Lake C. Its toxicity limits its applicability.[ citation needed ]
Barium chloride, along with other water-soluble barium salts, is highly toxic. [14] It irritates eyes and skin, causing redness and pain. It damages kidneys. Fatal dose of barium chloride for a human has been reported to be about 0.8-0.9 g. Systemic effects of acute barium chloride toxicity include abdominal pain, diarrhea, nausea, vomiting, cardiac arrhythmia, muscular paralysis, and death. The Ba 2+ ions compete with the K + ions, causing the muscle fibers to be electrically unexcitable, thus causing weakness and paralysis of the body. [3] Sodium sulfate and magnesium sulfate are potential antidotes because they form barium sulfate BaSO4, which is relatively non-toxic because of its insolubility in water.
Barium chloride is not classified as a human carcinogen. [3]
Magnesium carbonate, MgCO3, is an inorganic salt that is a colourless or white solid. Several hydrated and basic forms of magnesium carbonate also exist as minerals.
Magnesium chloride is an inorganic compound with the formula MgCl2. It forms hydrates MgCl2·nH2O, where n can range from 1 to 12. These salts are colorless or white solids that are highly soluble in water. These compounds and their solutions, both of which occur in nature, have a variety of practical uses. Anhydrous magnesium chloride is the principal precursor to magnesium metal, which is produced on a large scale. Hydrated magnesium chloride is the form most readily available.
Barium hydroxide is a chemical compound with the chemical formula Ba(OH)2. The monohydrate (x = 1), known as baryta or baryta-water, is one of the principal compounds of barium. This white granular monohydrate is the usual commercial form.
Barium sulfate (or sulphate) is the inorganic compound with the chemical formula BaSO4. It is a white crystalline solid that is odorless and insoluble in water. It occurs in nature as the mineral barite, which is the main commercial source of barium and materials prepared from it. Its opaque white appearance and its high density are exploited in its main applications.
Barium carbonate is the inorganic compound with the formula BaCO3. Like most alkaline earth metal carbonates, it is a white salt that is poorly soluble in water. It occurs as the mineral known as witherite. In a commercial sense, it is one of the most important barium compounds.
Lead(II) chloride (PbCl2) is an inorganic compound which is a white solid under ambient conditions. It is poorly soluble in water. Lead(II) chloride is one of the most important lead-based reagents. It also occurs naturally in the form of the mineral cotunnite.
In chemistry, water(s) of crystallization or water(s) of hydration are water molecules that are present inside crystals. Water is often incorporated in the formation of crystals from aqueous solutions. In some contexts, water of crystallization is the total mass of water in a substance at a given temperature and is mostly present in a definite (stoichiometric) ratio. Classically, "water of crystallization" refers to water that is found in the crystalline framework of a metal complex or a salt, which is not directly bonded to the metal cation.
Manganese(II) chloride is the dichloride salt of manganese, MnCl2. This inorganic chemical exists in the anhydrous form, as well as the dihydrate (MnCl2·2H2O) and tetrahydrate (MnCl2·4H2O), with the tetrahydrate being the most common form. Like many Mn(II) species, these salts are pink, with the paleness of the color being characteristic of transition metal complexes with high spin d5 configurations.
Strontium chloride (SrCl2) is a salt of strontium and chloride. It is a 'typical' salt, forming neutral aqueous solutions. As with all compounds of strontium, this salt emits a bright red colour in flame, and is commonly used in fireworks to that effect. Its properties are intermediate between those for barium chloride, which is more toxic, and calcium chloride.
Copper(II) chloride, also known as cupric chloride, is an inorganic compound with the chemical formula CuCl2. The monoclinic yellowish-brown anhydrous form slowly absorbs moisture to form the orthorhombic blue-green dihydrate CuCl2·2H2O, with two water molecules of hydration. It is industrially produced for use as a co-catalyst in the Wacker process.
Chromium(III) chloride (also called chromic chloride) is an inorganic chemical compound with the chemical formula CrCl3. It forms several hydrates with the formula CrCl3·nH2O, among which are hydrates where n can be 5 (chromium(III) chloride pentahydrate CrCl3·5H2O) or 6 (chromium(III) chloride hexahydrate CrCl3·6H2O). The anhydrous compound with the formula CrCl3 are violet crystals, while the most common form of the chromium(III) chloride are the dark green crystals of hexahydrate, CrCl3·6H2O. Chromium chlorides find use as catalysts and as precursors to dyes for wool.
Nickel(II) chloride (or just nickel chloride) is the chemical compound NiCl2. The anhydrous salt is yellow, but the more familiar hydrate NiCl2·6H2O is green. Nickel(II) chloride, in various forms, is the most important source of nickel for chemical synthesis. The nickel chlorides are deliquescent, absorbing moisture from the air to form a solution. Nickel salts have been shown to be carcinogenic to the lungs and nasal passages in cases of long-term inhalation exposure.
Iron(II) chloride, also known as ferrous chloride, is the chemical compound of formula FeCl2. It is a paramagnetic solid with a high melting point. The compound is white, but typical samples are often off-white. FeCl2 crystallizes from water as the greenish tetrahydrate, which is the form that is most commonly encountered in commerce and the laboratory. There is also a dihydrate. The compound is highly soluble in water, giving pale green solutions.
Cadmium chloride is a white crystalline compound of cadmium and chloride, with the formula CdCl2. This salt is a hygroscopic solid that is highly soluble in water and slightly soluble in alcohol. The crystal structure of cadmium chloride (described below), is a reference for describing other crystal structures. Also known are CdCl2•H2O and the hemipentahydrate CdCl2•2.5H2O.
Selenic acid is the inorganic compound with the formula H2SeO4. It is an oxoacid of selenium, and its structure is more accurately described as O2Se(OH)2. It is a colorless compound. Although it has few uses, one of its salts, sodium selenate is used in the production of glass and animal feeds.
Sodium molybdate, Na2MoO4, is useful as a source of molybdenum. This white, crystalline salt is often encountered as the dihydrate, Na2MoO4·2H2O.
Barium chlorate, Ba(ClO3)2, is the barium salt of chloric acid. It is a white crystalline solid, and like all soluble barium compounds, irritant and toxic. It is sometimes used in pyrotechnics to produce a green color. It also finds use in the production of chloric acid.
Chromium(III) sulfate usually refers to the inorganic compounds with the formula Cr2(SO4)3.x(H2O), where x can range from 0 to 18. Additionally, ill-defined but commercially important "basic chromium sulfates" are known. These salts are usually either violet or green solids that are soluble in water. It is commonly used in tanning leather.
Barium bromide is the chemical compound with the formula BaBr2. It is ionic and hygroscopic in nature.
Radium compounds are compounds containing the element radium (Ra). Due to radium's radioactivity, not many compounds have been well characterized. Solid radium compounds are white as radium ions provide no specific coloring, but they gradually turn yellow and then dark over time due to self-radiolysis from radium's alpha decay. Insoluble radium compounds coprecipitate with all barium, most strontium, and most lead compounds.