Sulfur Element Facts

16 S 32.06 Sulfur General | States | Energies Oxidation & Electrons | Appearance & Characteristics Reactions | Compounds | Radius | Conductivity Abundance & Isotopes Deposits of sulfur around a volcanic vent.

General:

Name: Sulfur	Symbol: S
Type: Non-Metal, Chalcogen	Atomic weight: 32.06
Density @ 293 K: 2.07 g/cm3	Atomic volume: 15.5 cm3/mol
Discovered: Sulfur has been known since ancient times and is referred to in the Bible as brimstone. The name may have been derived from the Arabic 'sufra', meaning yellow.

States

State (s, l, g): solid
Melting point: 388.4 K   (115.2 oC)	Boiling point: 717.9 K   (444.7 oC)

Energies

Specific heat capacity: 0.71 J g-1 K-1	Heat of atomization: 279 kJ mol-1
Heat of fusion: 1.7175 kJ mol-1	Heat of vaporization (sublimation): 9.8 kJ mol-1 of S2
1st ionization energy: 999.6 kJ mol-1	2nd ionization energy: 2251 kJ mol-1
3rd ionization energy: 3360.6 kJ mol-1	Electron affinity: 200.4144 kJ mol-1

Oxidation & Electrons

Shells: 2,8,6	Electron configuration: [Ne] 3s2 3p4
Minimum oxidation number: -2	Maximum oxidation number: 6
Min. common oxidation no.: -2	Max. common oxidation no.: 6
Electronegativity (Pauling Scale): 2.58	Polarizability volume: 2.9 Å3

Appearance & Characteristics

Structure: S8 rings	Color: yellow
Harmful effects: Elemental sulfur is considered to be of low toxicity. However, compounds of sulfur such as carbon disulfide, hydrogen sulfide, and sulfur dioxide are toxic and should be handled very carefully.	Hardness: 2 mohs
Characteristics: Sulfur is a soft, pale yellow, odorless, brittle solid. It is insoluble in water, but soluble in carbon disulfide. It exists in several crystalline and amorphous allotropes. Sulfur is multivalent and combines, with valence 2, 4, or 6, with nearly all other elements. Its most familiar compound is hydrogen sulfide, a toxic gas that smells like rotten eggs. Sulfur burns with a blue flame, oxidizing to sulfur dioxide.
Uses: Sulfur's main commercial use is as a reactant in the production of sulfuric acid (H2SO4). Sulfuric acid is the industrialized world's number one bulk chemical, required in large quantities in lead-acid batteries for automotive use. Sulfur is also used in the vulcanization of natural rubber, as a fungicide, in black gunpowder, in detergents and in the manufacture of phosphate fertilizers. Sulfur is essential to life as a minor component of fats, body fluids, and skeletal minerals.

Reactions

Reaction with air: vigorous, w/ht ⇒ SO2	Reaction with 6 M HCl: none
Reaction with 15 M HNO3: vigorous, ⇒ H2SO4, NOx	Reaction with 6 M NaOH: none

Compounds

Oxide(s): SO2, SO3	Chloride(s): S2Cl2, SCl2
Hydride(s): H2S (hydrogen sulfide)

Radius

Atomic radius: 100 pm	Ionic radius (1+ ion): pm
Ionic radius (2+ ion): pm	Ionic radius (3+ ion): pm
Ionic radius (2- ion): 170 pm	Ionic radius (1- ion): pm

Conductivity

Thermal conductivity: 0.205 W m-1 K-1

Electrical conductivity: 5.0 x 10-14 S cm-1

Abundance & Isotopes

Abundance earth's crust: 420 ppm by weight, 270 ppm by moles

Abundance solar system: 400 ppm by weight, 10 ppm by moles

Cost, pure: 50 $/100g

Cost, bulk: $/100g

Source: Elemental sulfur can be found naturally in areas of hot springs and in volcanic regions. Sulfur is also widely found in nature as iron pyrites (iron sulfide), galena (lead sulfide), gypsum (calcium sulfate), Epsom salts (magnesium sulfate) and many other minerals. Sulfur is recovered commercially from underground deposits using the Frasch Process - superheated water and steam are pumped underground, where they melt the sulfur, allowing it to be pumped to the surface. Sulfur is also obtained commercially as a by-product of refining crude oil.

Isotopes: Sulfur has 18 isotopes whose half-lives are known, with mass numbers 27 to 45. Of these, four are stable: 32S, 33S, 34S, and 36S. 95% of naturally occurring sulfur is in the form of 32S.