Lithium oxide

Last updated

Lithium oxide
Lithium-oxide-unit-cell-3D-balls-B.png
Lithium-oxide-unit-cell-3D-ionic.png
CaF2 polyhedra.png
__ Li +     __ O 2−
Li2O.jpg
Names
IUPAC name
Lithium oxide
Other names
Lithia
Kickerite
Dilithium Monoxide
Dilithium Oxide
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.031.823 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
RTECS number
  • OJ6360000
UNII
  • InChI=1S/2Li.O/q2*+1;-2 Yes check.svgY
    Key: FUJCRWPEOMXPAD-UHFFFAOYSA-N Yes check.svgY
  • InChI=1S/2Li.O/q2*+1;-2
    Key: FUJCRWPEOMXPAD-UHFFFAOYAW
  • Key: FUJCRWPEOMXPAD-UHFFFAOYSA-N
  • [Li+].[Li+].[O-2]
Properties
Li
2
O
Molar mass 29.88 g/mol
Appearancewhite solid
Density 2.013 g/cm3
Melting point 1,438 °C (2,620 °F; 1,711 K)
Boiling point 2,600 °C (4,710 °F; 2,870 K)
Reacts to form LiOH
log P 9.23
1.644 [1]
Structure
Antifluorite (cubic), cF12
Fm3m, No. 225
Tetrahedral (Li+); cubic (O2−)
Thermochemistry
1.8105 J/g K or 54.1 J/mol K
Std molar
entropy
(S298)
37.89 J/mol K
-20.01 kJ/g or -595.8 kJ/mol
-562.1 kJ/mol
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Corrosive, reacts violently with water
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 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazard W: Reacts with water in an unusual or dangerous manner. E.g. sodium, sulfuric acid
3
0
1
W
Flash point Non-flammable
Related compounds
Other anions
Lithium sulfide
Lithium selenide
Lithium telluride
Lithium polonide
Other cations
Sodium oxide
Potassium oxide
Rubidium oxide
Caesium oxide
Related lithium oxides
Lithium peroxide
Lithium superoxide
Related compounds
Lithium hydroxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

Lithium oxide (Li
2
O) or lithia is an inorganic chemical compound. It is a white solid. Although not specifically important, many materials are assessed on the basis of their Li2O content. For example, the Li2O content of the principal lithium mineral spodumene (LiAlSi2O6) is 8.03%. [2]

Contents

Production

Burning lithium metal produces lithium oxide. Burninglithium.jpg
Burning lithium metal produces lithium oxide.

Lithium oxide forms along with small amounts of lithium peroxide when lithium metal is burned in the air and combines with oxygen at temperatures above 100 °C: [3]

4Li + O
2
→ 2Li
2
O
.

Pure Li
2
O
can be produced by the thermal decomposition of lithium peroxide, Li
2
O
2
, at 450 °C [3] [2]

2Li
2
O
2
→ 2Li
2
O
+ O
2

Structure

Solid lithium oxide adopts an antifluorite structure with four-coordinated Li+ centers and eight-coordinated oxides. [4]

The ground state gas phase Li
2
O
molecule is linear with a bond length consistent with strong ionic bonding. [5] [6] VSEPR theory would predict a bent shape similar to H
2
O
.

Uses

Lithium oxide is used as a flux in ceramic glazes; and creates blues with copper and pinks with cobalt. Lithium oxide reacts with water and steam, forming lithium hydroxide and should be isolated from them.

Its usage is also being investigated for non-destructive emission spectroscopy evaluation and degradation monitoring within thermal barrier coating systems. It can be added as a co-dopant with yttria in the zirconia ceramic top coat, without a large decrease in expected service life of the coating. At high heat, lithium oxide emits a very detectable spectral pattern, which increases in intensity along with degradation of the coating. Implementation would allow in situ monitoring of such systems, enabling an efficient means to predict lifetime until failure or necessary maintenance.

Lithium metal might be obtained from lithium oxide by electrolysis, releasing oxygen as by-product.

Reactions

Lithium oxide absorbs carbon dioxide forming lithium carbonate:

Li
2
O
+ CO
2
Li
2
CO
3

The oxide reacts slowly with water, forming lithium hydroxide:

Li
2
O
+ H
2
O
→ 2LiOH

See also

Related Research Articles

<span class="mw-page-title-main">Alkali metal</span> Group of highly reactive chemical elements

The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). Together with hydrogen they constitute group 1, which lies in the s-block of the periodic table. All alkali metals have their outermost electron in an s-orbital: this shared electron configuration results in their having very similar characteristic properties. Indeed, the alkali metals provide the best example of group trends in properties in the periodic table, with elements exhibiting well-characterised homologous behaviour. This family of elements is also known as the lithium family after its leading element.

<span class="mw-page-title-main">Inorganic chemistry</span> Field of chemistry

Inorganic chemistry deals with synthesis and behavior of inorganic and organometallic compounds. This field covers chemical compounds that are not carbon-based, which are the subjects of organic chemistry. The distinction between the two disciplines is far from absolute, as there is much overlap in the subdiscipline of organometallic chemistry. It has applications in every aspect of the chemical industry, including catalysis, materials science, pigments, surfactants, coatings, medications, fuels, and agriculture.

<span class="mw-page-title-main">Hydride</span> Molecule with a hydrogen bound to a more electropositive element or group

In chemistry, a hydride is formally the anion of hydrogen (H), a hydrogen atom with two electrons. The term is applied loosely. At one extreme, all compounds containing covalently bound H atoms are called hydrides: water (H2O) is a hydride of oxygen, ammonia is a hydride of nitrogen, etc. For inorganic chemists, hydrides refer to compounds and ions in which hydrogen is covalently attached to a less electronegative element. In such cases, the H centre has nucleophilic character, which contrasts with the protic character of acids. The hydride anion is very rarely observed.

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

Potassium oxide (K2O) is an ionic compound of potassium and oxygen. It is a base. This pale yellow solid is the simplest oxide of potassium. It is a highly reactive compound that is rarely encountered. Some industrial materials, such as fertilizers and cements, are assayed assuming the percent composition that would be equivalent to K2O.

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

Lithium hydroxide is an inorganic compound with the formula LiOH. It can exist as anhydrous or hydrated, and both forms are white hygroscopic solids. They are soluble in water and slightly soluble in ethanol. Both are available commercially. While classified as a strong base, lithium hydroxide is the weakest known alkali metal hydroxide.

Cuprates are a class of compounds that contain copper (Cu) atom(s) in an anion. They can be broadly categorized into two main types:

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

Cobalt(II) chloride is an inorganic compound, a salt of cobalt and chlorine, with the formula CoCl
2
. The compound forms several hydrates CoCl
2
·nH
2
O
, for n = 1, 2, 6, and 9. Claims of the formation of tri- and tetrahydrates have not been confirmed. The anhydrous form is a blue crystalline solid; the dihydrate is purple and the hexahydrate is pink. Commercial samples are usually the hexahydrate, which is one of the most commonly used cobalt salts in the lab.

<span class="mw-page-title-main">Ozonide</span> Polyatomic ion (O3, charge –1), or cyclic compounds made from ozone and alkenes

Ozonide is the polyatomic anion O−3. Cyclic organic compounds formed by the addition of ozone to an alkene are also called ozonides.

Basic oxides are oxides that show basic properties, in opposition to acidic oxides. A basic oxide can either react with water to form a base, or with an acid to form a salt and water in a neutralization reaction.

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

Lithium aluminate, also called lithium aluminium oxide, is an inorganic chemical compound, an aluminate of lithium. In microelectronics, lithium aluminate is considered as a lattice matching substrate for gallium nitride. In nuclear technology, lithium aluminate is of interest as a solid tritium breeder material, for preparing tritium fuel for nuclear fusion. Lithium aluminate is a layered double hydroxide (LDH) with a crystal structure resembling that of hydrotalcite. Lithium aluminate solubility at high pH is much lower than that of aluminium oxides. In the conditioning of low- and intermediate level radioactive waste (LILW), lithium nitrate is sometimes used as additive to cement to minimise aluminium corrosion at high pH and subsequent hydrogen production. Indeed, upon addition of lithium nitrate to cement, a passive layer of LiH(AlO
2
)
2
· 5 H
2
O
is formed onto the surface of metallic aluminium waste immobilised in mortar. The lithium aluminate layer is insoluble in cement pore water and protects the underlying aluminium oxide covering the metallic aluminium from dissolution at high pH. It is also a pore filler. This hinders the aluminium oxidation by the protons of water and reduces the hydrogen evolution rate by a factor of 10.

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

Lithium peroxide is the inorganic compound with the formula Li2O2. It is a white, nonhygroscopic solid. Because of its high oxygen:mass and oxygen:volume ratios, the solid has been used to remove CO2 from the atmosphere in spacecraft.

Lithium superoxide is an unstable inorganic salt with formula LiO2. A radical compound, it can be produced at low temperature in matrix isolation experiments, or in certain nonpolar, non-protic solvents. Lithium superoxide is also a transient species during the reduction of oxygen in a lithium–air galvanic cell, and serves as a main constraint on possible solvents for such a battery. For this reason, it has been investigated thoroughly using a variety of methods, both theoretical and spectroscopic.

Lithium carbide, Li
2
C
2
, often known as dilithium acetylide, is a chemical compound of lithium and carbon, an acetylide. It is an intermediate compound produced during radiocarbon dating procedures. Li
2
C
2
is one of an extensive range of lithium-carbon compounds which include the lithium-rich Li
4
C
, Li
6
C
2
, Li
8
C
3
, Li
6
C
3
, Li
4
C
3
, Li
4
C
5
, and the graphite intercalation compounds LiC
6
, LiC
12
, and LiC
18
.
Li
2
C
2
is the most thermodynamically-stable lithium-rich carbide and the only one that can be obtained directly from the elements. It was first produced by Moissan, in 1896 who reacted coal with lithium carbonate.

<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">Oxygen compounds</span>

The oxidation state of oxygen is −2 in almost all known compounds of oxygen. The oxidation state −1 is found in a few compounds such as peroxides. Compounds containing oxygen in other oxidation states are very uncommon: −12 (superoxides), −13 (ozonides), 0, +12 (dioxygenyl), +1, and +2.

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

Cobalt(II) hydroxide or cobaltous hydroxide is the inorganic compound with the formula Co(OH)
2
, consisting of divalent cobalt cations Co2+
and hydroxide anions OH
. The pure compound, often called the "beta form" is a pink solid insoluble in water.

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">Metal peroxide</span>

Metal peroxides are metal-containing compounds with ionically- or covalently-bonded peroxide (O2−
2
) 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 (H2SO5). In contrast to the purely ionic character of alkali metal peroxides, peroxides of transition metals have a more covalent character.

Cobalt compounds are chemical compounds formed by cobalt with other elements.

Gallium compounds are compounds containing the element gallium. These compounds are found primarily in the +3 oxidation state. The +1 oxidation state is also found in some compounds, although it is less common than it is for gallium's heavier congeners indium and thallium. For example, the very stable GaCl2 contains both gallium(I) and gallium(III) and can be formulated as GaIGaIIICl4; in contrast, the monochloride is unstable above 0 °C, disproportionating into elemental gallium and gallium(III) chloride. Compounds containing Ga–Ga bonds are true gallium(II) compounds, such as GaS (which can be formulated as Ga24+(S2−)2) and the dioxan complex Ga2Cl4(C4H8O2)2. There are also compounds of gallium with negative oxidation states, ranging from -5 to -1, most of these compounds being magnesium gallides (MgxGay).

References

  1. Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN   0-07-049439-8
  2. 1 2 Wietelmann, Ulrich and Bauer, Richard J. (2005) "Lithium and Lithium Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH: Weinheim. doi : 10.1002/14356007.a15_393.
  3. 1 2 Greenwood, Norman N.; Earnshaw, Alan (1984). Chemistry of the Elements. Oxford: Pergamon Press. pp. 97–99. ISBN   978-0-08-022057-4.
  4. Zintl, Eduard; Harder, A.; Dauth, B. (1934). "Gitterstruktur der Oxyde, Sulfide, Selenide und Telluride des Lithiums, Natriums und Kaliums". Zeitschrift für Elektrochemie und Angewandte Physikalische Chemie (in German). 40 (8): 588–593. doi:10.1002/bbpc.19340400811. S2CID   94213844.
  5. Wells A. F. (1984) Structural Inorganic Chemistry 5th edition Oxford Science Publications ISBN   0-19-855370-6
  6. A spectroscopic determination of the bond length of the LiOLi molecule: Strong ionic bonding, D. Bellert, W. H. Breckenridge, J. Chem. Phys. 114, 2871 (2001); doi : 10.1063/1.1349424