Barium oxide

Last updated
Barium oxide
Barium-oxide-3D-vdW.png
Barium oxide.JPG
Names
Other names
  • Neutral barium oxide (1:1)
  • Barium protoxide
  • Calcined baryta
  • Baria
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.013.753 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 215-127-9
PubChem CID
RTECS number
  • CQ9800000
UNII
UN number 1884
  • InChI=1S/Ba.O Yes check.svgY
    Key: QVQLCTNNEUAWMS-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/Ba.O/rBaO/c1-2
    Key: QVQLCTNNEUAWMS-FXUTYLCTAB
  • [Ba]=O
Properties
BaO
Molar mass 153.326 g/mol
Appearancewhite solid
Density 5.72 g/cm3, solid
Melting point 1,923 °C (3,493 °F; 2,196 K)
Boiling point ~2,000 °C (3,630 °F; 2,270 K)
  • 3.48 g/100 mL (20 °C)
  • 90.8 g/100 mL (100 °C)
  • Reacts to form Ba(OH)2
Solubility soluble in ethanol, dilute mineral acids and alkalies; insoluble in acetone and liquid ammonia
-29.1·10−6 cm3/mol
Structure
cubic, cF8
Fm3m, No. 225
Octahedral
Thermochemistry
47.7 J/K mol
Std molar
entropy (S⦵298)
70 J·mol−1·K−1 [1]
−582 kJ·mol−1 [1]
Hazards
GHS labelling:
GHS-pictogram-acid.svg GHS-pictogram-skull.svg GHS-pictogram-exclam.svg
Danger
H301, H302, H314, H315, H332, H412
P210, P220, P221, P260, P261, P264, P270, P271, P273, P280, P283, P301+P310, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P312, P304+P340, P305+P351+P338, P306+P360, P310, P312, P321, P330, P332+P313, P362, P363, P370+P378, P371+P380+P375, P405, P501
NFPA 704 (fire diamond)
NFPA 704.svgHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
3
0
0
Flash point Non-flammable
Related compounds
Other anions
Other cations
Supplementary data page
Barium oxide (data page)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Barium oxide, also known as baria, is a white hygroscopic non-flammable compound with the formula BaO. It has a cubic structure and is used in cathode-ray tubes, crown glass, and catalysts. It is harmful to human skin and if swallowed in large quantity causes irritation. Excessive quantities of barium oxide may lead to death.

Contents

It is prepared by heating barium carbonate with coke, carbon black or tar or by thermal decomposition of barium nitrate.[ citation needed ]

Uses

Barium oxide is used as a coating for hot cathodes, for example, those in cathode-ray tubes. It replaced lead(II) oxide in the production of certain kinds of glass such as optical crown glass. While lead oxide raised the refractive index, it also raised the dispersive power, which barium oxide does not alter. [2] Barium oxide also has use as an ethoxylation catalyst in the reaction of ethylene oxide and alcohols, which takes place between 150 and 200 °C. [3]

It is most known for its use in the Brin process, named after its inventors, a reaction that was used as a large scale method to produce oxygen before air separation became the dominant method in the beginning of the 20th century, as BaO can be a source of pure oxygen through heat fluctuation.

BaO(s) + ½O2(g) ⇌ BaO2(s)

It oxidises to BaO2 by formation of a peroxide ion ([O−O]2−, or O2−2) — with the same charge of O2−, and therefore keeping the electrochemical balance with the most stable Ba2+. Using the Kröger-Vink notation,

½O2(g) + O2–
O ⇌ [O
2]2–
O

where J
O is the species J in the oxygen position within the rock-salt lattice. The complete peroxidation of BaO to BaO2 occurs at moderate temperatures by oxygen uptake within the BaO rock-salt lattice:

Barium oxide peroxidation from oxygen uptake, adapted from Middleburgh et al, 2012. Oxygen incorporation into BaO.png
Barium oxide peroxidation from oxygen uptake, adapted from Middleburgh et al, 2012.




Calculations using Density Functional Theory (DFT) suggest that the oxygen incorporation reaction is exothermic, and that the most energetically favoured occupation site is indeed the peroxide ion at the oxide lattice — other than interstitial positions, for instance. However, the increased entropy of the system is what leads BaO2 to decompose to BaO and release O2 between 800 and 1100 K (520 and 820 °C). [4] The reaction was used as a large scale method to produce oxygen before air separation became the dominant method in the beginning of the 20th century. The method was named the Brin process, after its inventors. [5]

Preparation

Barium oxide from metalic barium readly forms from its exothermic oxidation with dioxygen in air:

2 Ba(s) + O2(g) → 2 BaO(s).

It's most commonly made by heating barium carbonate at temperatures of 1000–1450 °C.

BaCO3(s) → BaO(s) + CO2(g)

Likewise, it is often formed through the thermal decomposition of other barium salts, [6] like barium nitrate. [7]

Safety issues

Barium oxide is an irritant. If it contacts the skin or the eyes or is inhaled it causes pain and redness. However, it is more dangerous when ingested. It can cause nausea and diarrhea, muscle paralysis, cardiac arrhythmia, and can cause death. If ingested, medical attention should be sought immediately.

Barium oxide should not be released environmentally; it is harmful to aquatic organisms. [8]

See also

Related Research Articles

<span class="mw-page-title-main">Barium</span> Chemical element with atomic number 56 (Ba)

Barium is a chemical element; it has symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found in nature as a free element.

<span class="mw-page-title-main">Hydrogen peroxide</span> Chemical compound

Hydrogen peroxide is a chemical compound with the formula H2O2. In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution in water for consumer use and in higher concentrations for industrial use. Concentrated hydrogen peroxide, or "high-test peroxide", decomposes explosively when heated and has been used as both a monopropellant and an oxidizer in rocketry.

<span class="mw-page-title-main">Oxide</span> Chemical compound where oxygen atoms are combined with atoms of other elements

An oxide is a chemical compound containing at least one oxygen atom and one other element in its chemical formula. "Oxide" itself is the dianion of oxygen, an O2– ion with oxygen in the oxidation state of −2. Most of the Earth's crust consists of oxides. Even materials considered pure elements often develop an oxide coating. For example, aluminium foil develops a thin skin of Al2O3 that protects the foil from further oxidation.

<span class="mw-page-title-main">Manganese dioxide</span> Chemical compound

Manganese dioxide is the inorganic compound with the formula MnO
2. This blackish or brown solid occurs naturally as the mineral pyrolusite, which is the main ore of manganese and a component of manganese nodules. The principal use for MnO
2 is for dry-cell batteries, such as the alkaline battery and the zinc–carbon battery. MnO
2 is also used as a pigment and as a precursor to other manganese compounds, such as KMnO
4. It is used as a reagent in organic synthesis, for example, for the oxidation of allylic alcohols. MnO
2 has an α-polymorph that can incorporate a variety of atoms in the "tunnels" or "channels" between the manganese oxide octahedra. There is considerable interest in α-MnO
2 as a possible cathode for lithium-ion batteries.

<span class="mw-page-title-main">Barium nitrate</span> Chemical compound

Barium nitrate is the inorganic compound with the chemical formula Ba(NO3)2. It, like most barium salts, is colorless, toxic, and water-soluble. It burns with a green flame and is an oxidizer; the compound is commonly used in pyrotechnics.

<span class="mw-page-title-main">Sodium chlorate</span> Chemical compound

Sodium chlorate is an inorganic compound with the chemical formula NaClO3. It is a white crystalline powder that is readily soluble in water. It is hygroscopic. It decomposes above 300 °C to release oxygen and leaves sodium chloride. Several hundred million tons are produced annually, mainly for applications in bleaching pulp to produce high brightness paper.

<span class="mw-page-title-main">Chemical decomposition</span> Breakdown of a chemical species into two or more parts; reverse process of a synthesis reaction

Chemical decomposition, or chemical breakdown, is the process or effect of simplifying a single chemical entity into two or more fragments. Chemical decomposition is usually regarded and defined as the exact opposite of chemical synthesis. In short, the chemical reaction in which two or more products are formed from a single reactant is called a decomposition reaction.

<span class="mw-page-title-main">Thermal decomposition</span> Chemical decomposition caused by heat

Thermal decomposition, or thermolysis, is a chemical decomposition of a substance caused by heat. The decomposition temperature of a substance is the temperature at which the substance chemically decomposes. The reaction is usually endothermic as heat is required to break chemical bonds in the compound undergoing decomposition. If decomposition is sufficiently exothermic, a positive feedback loop is created producing thermal runaway and possibly an explosion or other chemical reaction. Thermal decomposition is a chemical reaction where heat is a reactant. Since heat is a reactant, these reactions are endothermic meaning that the reaction requires thermal energy to break the chemical bonds in the molecule.

<span class="mw-page-title-main">Uranium trioxide</span> Chemical compound

Uranium trioxide (UO3), also called uranyl oxide, uranium(VI) oxide, and uranic oxide, is the hexavalent oxide of uranium. The solid may be obtained by heating uranyl nitrate to 400 °C. Its most commonly encountered polymorph is amorphous UO3.

<span class="mw-page-title-main">Uranate</span> Uranium oxyanion associated with a monovalent or divalent cation

A uranate is a ternary oxide involving the element uranium in one of the oxidation states 4, 5 or 6. A typical chemical formula is MxUyOz, where M represents a cation. The uranium atom in uranates(VI) has two short collinear U–O bonds and either four or six more next nearest oxygen atoms. The structures are infinite lattice structures with the uranium atoms linked by bridging oxygen atoms.

<span class="mw-page-title-main">Barium peroxide</span> Chemical compound

Barium peroxide is an inorganic compound with the formula BaO2. This white solid is one of the most common inorganic peroxides, and it was the first peroxide compound discovered. Being an oxidizer and giving a vivid green colour upon ignition, it finds some use in fireworks; historically, it was also used as a precursor for hydrogen peroxide.

<span class="mw-page-title-main">Barium chlorate</span> Chemical compound

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 colour. It also finds use in the production of chloric acid.

<span class="mw-page-title-main">Strontium peroxide</span> Chemical compound

Strontium peroxide is an inorganic compound with the formula Sr O2 that exists in both anhydrous and octahydrate form, both of which are white solids. The anhydrous form adopts a structure similar to that of calcium carbide.

<span class="mw-page-title-main">Lithium cobalt oxide</span> Chemical compound

Lithium cobalt oxide, sometimes called lithium cobaltate or lithium cobaltite, is a chemical compound with formula LiCoO
2. The cobalt atoms are formally in the +3 oxidation state, hence the IUPAC name lithium cobalt(III) oxide.

<span class="mw-page-title-main">Barium ferrate</span> Chemical compound

Barium ferrate is the chemical compound of formula BaFeO4. This is a rare compound containing iron in the +6 oxidation state. The ferrate(VI) ion has two unpaired electrons, making it paramagnetic. It is isostructural with BaSO4, and contains the tetrahedral [FeO4]2− anion.

<span class="mw-page-title-main">Manganese(II) oxide</span> Chemical compound

Manganese(II) oxide is an inorganic compound with chemical formula MnO. It forms green crystals. The compound is produced on a large scale as a component of fertilizers and food additives.

<span class="mw-page-title-main">Bromous acid</span> Chemical compound

Bromous acid is the inorganic compound with the formula of HBrO2. It is an unstable compound, although salts of its conjugate base – bromites – have been isolated. In acidic solution, bromites decompose to bromine.

The lithium–air battery (Li–air) is a metal–air electrochemical cell or battery chemistry that uses oxidation of lithium at the anode and reduction of oxygen at the cathode to induce a current flow.

<span class="mw-page-title-main">Brin process</span> Chemical process

Brin process is a now-obsolete industrial scale production process for oxygen. In this process barium oxide reacts at 500–600 °C with air to form barium peroxide which decomposes at above 800 °C by releasing oxygen.

<span class="mw-page-title-main">Metal peroxide</span> Metal-containing compounds with peroxide (O2) ions/groups

In chemistry, metal peroxides are metal-containing compounds with ionically- or covalently-bonded peroxide groups. This large family of compounds can be divided into ionic and covalent peroxide. The first class mostly contains the peroxides of the alkali and alkaline earth metals whereas the covalent peroxides are represented by such compounds as hydrogen peroxide and peroxymonosulfuric acid. In contrast to the purely ionic character of alkali metal peroxides, peroxides of transition metals have a more covalent character.

References

  1. 1 2 Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. ISBN   978-0-618-94690-7.
  2. ↑ "Barium Oxide (chemical compound)". Encyclopædia Britannica. 2007. Retrieved 2007-02-19.
  3. ↑ Nield, Gerald; Washecheck, Paul; Yang, Kang (1980-07-01). "United States Patent 4210764" . Retrieved 2007-02-20.
  4. 1 2 Middleburgh, Simon C.; Lagerlof, Karl Peter D.; Grimes, Robin W. (2013). "Accommodation of Excess Oxygen in Group II Monoxides". Journal of the American Ceramic Society. 96 (1): 308–311. doi:10.1111/j.1551-2916.2012.05452.x. ISSN   1551-2916.
  5. ↑ Jensen, William B. (2009). "The Origin of the Brin Process for the Manufacture of Oxygen". Journal of Chemical Education. 86 (11): 1266. Bibcode:2009JChEd..86.1266J. doi:10.1021/ed086p1266.
  6. ↑ "Compounds of barium: barium (II) oxide". Web Elements. The University of Sheffield. 2007-01-26. Retrieved 2007-02-22.
  7. ↑ Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN   0-07-049439-8
  8. ↑ "Barium Oxide (ICSC)". IPCS. October 1999. Archived from the original on 26 February 2007. Retrieved 2007-02-19.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.