Lithium

Lithium

General:

Name: Lithium
Type: Alkali Metal
Density @ 293 K: 0.53 g/cm³ Symbol: Li
Atomic weight: 6.941
Atomic volume: 13.10 cm³/mol

Discovery of Lithium
Lithium was discovered by Johan Arfvedson in 1817, in an analysis of petalite (LiAlSi₄O₁₀).

He found the petalite contained "silica, alumina and alkali."

The new alkali metal in the petalite had unique properties. It took more acid to neutralize a sodium salt. The alkali new potassium differed because it gives no precipitate with tartaric acid and, unlike sodium carbonate was its low solubility.

Arfvedson tried to produce a pure sample of the new metal by electrolysis, but it failed, the battery it used was not powerful enough.

The pure metal was isolated in the following year by both William Humphry Davy and Brande work independently.

Davy obtained a small amount of lithium metal by electrolysis of lithium carbonate.
He noted the new item was a red flame a bit like strontium and produces an alkaline solution when dissolved in water.

In days of less safety conscious than the present, lithium Brande said, "the solution tastes bitter, like the other sets 'alkali.'"

In 1855, Robert Bunsen and Augustus Matthiessen were independently produce large quantities of metal by electrolysis of molten lithium chloride.

Name lithium is derived from "lithos", the Greek word for "stone."

States

State (s, l, g): solid
Melting point: 453.69 K   (180.54 ^oC)

Boiling point: 1615 K   (1347 ^oC)

Appearance

Structure: bcc: body-centered cubic
Hardness: 0.6 mohs

Color: silvery


Harmful effects:
Lithium is corrosive, causing skin burns as a result of the caustic hydroxide produced in contact with moisture. Women taking lithium carbonate for bi-polar disorder may be advised to vary their treatment during pregnancy as lithium may cause birth defects.

Reactions & Compounds

Reaction with air: vigorous,⇒ Li₂O
Reaction with 15 M HNO₃: vigorous,⇒ LiNO₃
Oxide(s): Li₂O
Hydride(s): LiH

Reaction with 6 M HCl: vigorous,⇒ H₂, LiCl
Reaction with 6 M NaOH: mild, ⇒ H₂, LiOH
Chloride(s): LiCl

Radius

Atomic radius: 145 pm
Ionic radius (2+ ion): pm
Ionic radius (2- ion): pm

Ionic radius (1+ ion): 90 pm
Ionic radius (3+ ion): pm
Ionic radius (1- ion): pm

Conductivity

Thermal conductivity: 84.8 W m^-1 K^-1

Electrical conductivity: 11.7 x 10⁶ S cm^-1

Energies

Specific heat capacity: 3.58 J g^-1 K^-1
Heat of fusion: 3.00 kJ mol^-1
1^st ionization energy: 520.2 kJ mol^-1
3^rd ionization energy: 11815.0 kJ mol^-1

Heat of atomization: 159 kJ mol^-1
Heat of vaporization: 147.1 kJ mol^-1
2^nd ionization energy: 7298.1 kJ mol^-1
Electron affinity: 59.63 kJ mol^-1

Oxidation & Electrons

Shells: 2,1
Minimum oxidation number: -1
Min. common oxidation no.: 0
Electronegativity (Pauling Scale): 0.98

Electron configuration: 1s² 2s¹
Maximum oxidation number: 1
Max. common oxidation no.: 1
Polarizability volume: 24.3 ų

characteristics:
Lithium is soft, silvery white and is the least dense metal. It is very reactive and does not occur freely in nature.

Freshly cut surfaces oxidize rapidly in air to form a black oxide coating. He is the only metal (but see radium) which reacts with nitrogen at room temperature, forming lithium nitride.

Lithium burns with a red flame, but when the metal burns well enough, the flame becomes a brilliant white.

Lithium has a high specific heat capacity and there is like a liquid over a wide temperature range.

uses:
Pure metal lithium is used in rechargeable lithium-ion and the metal is alloyed with aluminum, copper, manganese and cadmium to make parts for high performance aircraft.

Lithium also has various nuclear applications, such as a coolant in nuclear breeder reactors and a source of tritium, which is formed by bombarding lithium with neutrons.

Lithium carbonate is used as a mood-stabilizing drug.

Lithium chloride and bromide are used as desiccants.

Lithium stearate is used as a lubricant all-purpose and high temperature.

Interesting Facts: Did You Know?

Interesting Facts about Lithium: Did You Know?

• Lithium is believed to be one of only three elements - the others are hydrogen and helium - produced in significant quantities by the Big Bang.
• Lithium is the only alkali metal that reacts with nitrogen.
• Humphrey Davy produced some of the world's first lithium metal from lithium carbonate. Today lithium carbonate - or more precisely the lithium ions in lithium carbonate - are used to inhibit the manic phase of bipolar (manic-depressive) disorder.
• Batteries based on lithium have revolutionized consumer devices such as computers and cell phones. For a given battery weight, lithium batteries pack a lot of energy compared with batteries based on other metals; in other words, lithium batteries have high energy density.

Abundance & Isotopes

Abundance earth's crust: 20 parts per million by weight, 60 parts per million by moles
Abundance solar system: 60 parts per trillion by weight, 10 parts per trillion by moles
Cost, pure: $27 per 100g
Cost, bulk: $9.50 per 100g

Source: Lithium does not occur as a free element in nature. It is found in small amounts in ores from igneous rocks and in salts from mineral springs. Pure lithium metal is produced by electrolysis from a mixture of fused (molten) lithium chloride and potassium chloride.

Isotopes: Lithium has 7 isotopes whose half-lives are known, with mass numbers 5 to 11. Of these, two are stable: ⁶Li and ⁷Li.