http://www.youtube.com/watch?v=dQBs00w3Ca8
Kamis, 21 Januari 2010
Sodium chloride
Jump to: navigation, search
"NaCl" redirects here. For the Google technology, see Google Native Client.
This article is about the chemical compound. For sodium chloride in the diet, see Salt. For sodium chloride as a mineral, see Halite.
Sodium chloride
Halite(Salt)USGOV.jpg
Sodium-chloride-3D-ionic.png
IUPAC name
[hide]
Sodium chloride
Other names Common salt; halite; table salt; rock salt
Identifiers
CAS number 7647-14-5 Yes check.svgY
PubChem 5234
ChemSpider ID 5044
RTECS number VZ4725000
Properties
Molecular formula NaCl
Molar mass 58.443 g/mol
Appearance Colorless/white crystalline solid
Odor Odorless
Density 2.165 g/cm3
Melting point
801 °C, 1074 K, 1474 °F
Boiling point
1413 °C, 1686 K, 2575 °F
Solubility in water 35.6 g/100 mL (0 °C)
35.9 g/100 mL (25 °C)
39.1 g/100 mL (100 °C)
Solubility soluble in glycerol, ethylene glycol, formic acid
insoluble in HCl
Solubility in methanol 1.49 g/100 mL
Solubility in ammonia 2.15 g/100 mL
Acidity (pKa) 6.7-7.3
Refractive index (nD) 1.5442 (589 nm)
Structure
Crystal structure Cubic (see text), cF8
Space group Fm3m, No. 225
Lattice constant a = 564.02 pm
Coordination
geometry Octahedral (Na+)
Octahedral (Cl−)
Hazards
MSDS External MSDS
EU Index Not listed
NFPA 704
NFPA 704.svg
0
1
0
Flash point Non-flammable
LD50 3000–8000 mg/kg (oral in rats, mice, rabbits)[1]
Related compounds
Other anions Sodium fluoride
Sodium bromide
Sodium iodide
Other cations Lithium chloride
Potassium chloride
Rubidium chloride
Caesium chloride
Supplementary data page
Structure and
properties n, εr, etc.
Thermodynamic
data Phase behaviour
Solid, liquid, gas
Spectral data UV, IR, NMR, MS
Yes check.svgY (what is this?) (verify)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references
Close up view of NaCl crystals.
Sodium chloride, also known as salt, common salt, table salt, or halite, is an ionic compound with the formula NaCl. Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multicellular organisms. As the major ingredient in edible salt, it is commonly used as a condiment and food preservative.
Contents
[hide]
* 1 Production and use
o 1.1 Synthetic uses
o 1.2 Biological uses
o 1.3 Optical uses
o 1.4 Optical data
o 1.5 Household uses
o 1.6 Firefighting uses
o 1.7 In weather
* 2 Biological functions
* 3 Crystal structure
* 4 Road salt
o 4.1 Additives
* 5 Alternative names
* 6 See also
* 7 References
* 8 Further reading
* 9 External links
[edit] Production and use
Salt is currently mass-produced by evaporation of seawater or brine from other sources, such as brine wells and salt lakes, and by mining rock salt, called halite. In 2002, world production was estimated at 210 million metric tons, the top five producers (in million tonnes) being the United States (40.3), China (32.9), Germany (17.7), India (14.5) and Canada (12.3).[2]
As well as the familiar uses of salt in cooking, salt is used in many applications, from manufacturing pulp and paper, to setting dyes in textiles and fabric, to producing soaps, detergents, and other bath products. It is the major source of industrial chlorine and sodium hydroxide, and used in almost every industry.
Sodium chloride is sometimes used as a cheap and safe desiccant because it appears to have hygroscopic properties, making salting an effective method of food preservation historically; as it draws water out of bacteria through osmotic pressure preventing them from reproducing and causing food to spoil. Even though more effective desiccants are available, few are safe for humans to ingest.
Israeli and Jordanian salt evaporation ponds at the south end of the Dead Sea.
Mounds of salt, Salar de Uyuni, Bolivia.
Modern rock salt mine near Mount Morris, New York, United States.
Evaporation lagoons, Aigues-Mortes, France.
Solubility of NaCl in various solvents
(g NaCl / 100 g of solvent at 25 °C)
H2O 36
Liquid ammonia 3.02
Methanol 1.4
Sulfolane 0.005
Formic acid 5.2
Acetone 0.000042
Formamide 9.4
Acetonitrile 0.0003
Dimethylformamide 0.04
Reference:
Burgess, J. Metal Ions in Solution
(Ellis Horwood, New York, 1978)
ISBN 0-85312-027-7
[edit] Synthetic uses
Sodium chloride is also the raw material used to produce chlorine which itself is required for sterilization and the production of many modern materials including PVC, pesticides and epoxy resins. Industrially, elemental chlorine is usually produced by the electrolysis of sodium chloride dissolved in water. Along with chlorine, this chloralkali process yields hydrogen gas and sodium hydroxide, according to the chemical equation
2NaCl + 2H2O → Cl2 + H2 + 2NaOH
Sodium metal is produced commercially through the electrolysis of liquid sodium chloride. This is now done in a Down's cell in which sodium chloride is mixed with calcium chloride to lower the melting point below 700 °C. As calcium is more electropositive than sodium, no calcium will be formed at the cathode. This method is less expensive than the previous method of electrolyzing sodium hydroxide.
Sodium chloride is used in other chemical processes for the large-scale production of compounds containing sodium or chlorine. In the Solvay process, sodium chloride is used for producing sodium carbonate and calcium chloride. In the Mannheim process and in the Hargreaves process, it is used for the production of sodium sulfate and hydrochloric acid.
[edit] Biological uses
Many micro organisms cannot live in an overly salty environment: water is drawn out of their cells by osmosis. For this reason salt is used to preserve some foods, such as smoked bacon or fish. It can also be used to detach leeches that have attached themselves to feed. It is also used to disinfect wounds.
[edit] Optical uses
Pure NaCl crystal is an optical compound with a wide transmission range from 200 nm to 20 um. It was often used in the infrared spectrum range and it is still used sometimes.
NaCl crystal is soft, hygroscopic and inexpensive. This limits its application to protected environment or for short term uses (prototyping). Exposed to free air NaCl optics will "rot".
Today tougher crystals like ZnSe are used instead of NaCl (for the IR spectral range).
[edit] Optical data
* Transmitivity: 92% (from 400 nm to 13μm)
* Refractive Index: 1.494 @ 10μm
* Reflection Loss: 7.5% @ 10μm (2 surfaces)
* dN/dT: -36.2 x 10-6/°C @ 0.7μm
Household uses
Since at least medieval times, people have used salt as a cleansing agent rubbed on household surfaces. It is also used in many brands of shampoo, and popularly to de-ice driveways and patches of ice.
At one time salt water was used to clean teeth.
[edit] Firefighting uses
A class D fire extinguisher for various metals
Sodium Chloride is the principal extinguishing agent in fire extinguishers (Met-L-X, Super D) used on combustible metal fires such as magnesium, potassium, sodium, and NaK alloys (Class D). Thermoplastic powder is added to the mixture, along with waterproofing (metal stearates) and anti-caking materials (tricalcium phosphate) to form the extinguishing agent. When it is applied to the fire, the salt acts like a heat sink, dissipating heat from the fire, and also forms an oxygen-excluding crust to smother the fire. The plastic additive melts and helps the crust maintain its integrity until the burning metal cools below its ignition temperature. This type of extinguisher was invented in the late 1940s in the cartridge-operated type shown here, although stored pressure versions are now popular. Common sizes are 30 lb. portable and 350 lb. wheeled.
[edit] In weather
Clouds above the Pacific
Small particles of sea salt are the dominant cloud condensation nuclei well out at sea, which allow the formation of clouds in otherwise non-polluted air.[3] Snow removal by addition of salt (salting) is done to make travel easier and safer, and decrease the long term impact of a heavy snowfall on human populations. This process is done by both individual households and by governments and institutions and utilizes salt as well as other chloride-based chemicals to eliminate snow from road surfaces and sidewalks.[4]
[edit] Biological functions
In humans, a high-salt intake has long been known to generally raise blood pressure, especially in certain individuals. More recently, it was demonstrated to attenuate nitric oxide production. Nitric oxide (NO) contributes to vessel homeostasis by inhibiting vascular smooth muscle contraction and growth, platelet aggregation, and leukocyte adhesion to the endothelium.[5][6]
[edit] Crystal structure
The crystal structure of sodium chloride. Each ion has six nearest neighbors, with octahedral geometry.
Main article: Cubic crystal system
Sodium chloride forms crystals with face-centered cubic symmetry. In these, the larger chloride ions, shown to the right as green spheres, are arranged in a cubic close-packing, while the smaller sodium ions, shown to the right as silver spheres, fill all the cubic gaps between them. Each ion is surrounded by six ions of the other kind; the surrounding ions are located at the vertices of a regular octahedron.
This same basic structure is found in many other minerals and is commonly known as the halite or rock-salt crystal structure. It can be represented as a face-centered cubic (fcc) lattice with a two atom basis. The first atom is located at each lattice point, and the second atom is located half way between lattice points along the fcc unit cell edge.
It is held together by an ionic bond which is produced by electrostatic forces arising from the difference in charge between the ions.
[edit] Road salt
Magnesium chloride
While salt was once a scarce commodity in history, industrialized production has now made salt plentiful. Approximately 51% of world output is now used by cold countries to de-ice roads in winter, both in grit bins and spread by winter service vehicles. Calcium chloride is preferred over sodium chloride, since CaCl2 releases energy upon forming a solution with water, heating any ice or snow it is in contact with. It also lowers the freezing point, depending on the concentration. NaCl does not release heat upon solution; however, it does lower the freezing point. It is also more readily available and does not have any special handling or storage requirements, unlike calcium chloride. The salinity (S) of water is measured as grams salt per kilogram (1000g) water, and the freezing temperatures are as follows.
S(g/kg) 0 10 20 24.7 30 35
T(freezing) (C) 0 -0.5 -1.08 -1.33 -1.63 -1.91
[edit] Additives
Most table salt sold for consumption today is not pure sodium chloride. In 1911 magnesium carbonate was first added to salt to make it flow more freely.[7] In 1924 trace amounts of iodine in form of sodium iodide, potassium iodide or potassium iodate were first added, to reduce the incidence of simple goiter.[8]
Salt for de-icing in the UK predominantly comes from a single mine in Winsford in Cheshire [[1]]. Prior to distribution it has an anti-caking agent added, sodium hexacyanoferrate(II) at less than 100ppm, this treatment enables rock salt to flow freely out of the gritting vehicles despite being stockpiled prior to use. In recent years this additive has also been used in table salt.
Alternative names
* NaCl, Sodium monochloride
* Table salt, Sal Culinare or Sal Culinaris
* Common Salt, Sal Commune
* Muriate of soda, Muriate of natrium, Chloride of Sodium, Hydrochlorate of Soda (older names)
* Sodii Chloridum, SodAe Hydro-chloras, SodAe Murias (ancient names)
* Nat Mur for Natrum Muriaticum, Natrum Muriatica, or even Natrium Muriate (homeopathic/Biochemic cell salts)
Jump to: navigation, search
"NaCl" redirects here. For the Google technology, see Google Native Client.
This article is about the chemical compound. For sodium chloride in the diet, see Salt. For sodium chloride as a mineral, see Halite.
Sodium chloride
Halite(Salt)USGOV.jpg
Sodium-chloride-3D-ionic.png
IUPAC name
[hide]
Sodium chloride
Other names Common salt; halite; table salt; rock salt
Identifiers
CAS number 7647-14-5 Yes check.svgY
PubChem 5234
ChemSpider ID 5044
RTECS number VZ4725000
Properties
Molecular formula NaCl
Molar mass 58.443 g/mol
Appearance Colorless/white crystalline solid
Odor Odorless
Density 2.165 g/cm3
Melting point
801 °C, 1074 K, 1474 °F
Boiling point
1413 °C, 1686 K, 2575 °F
Solubility in water 35.6 g/100 mL (0 °C)
35.9 g/100 mL (25 °C)
39.1 g/100 mL (100 °C)
Solubility soluble in glycerol, ethylene glycol, formic acid
insoluble in HCl
Solubility in methanol 1.49 g/100 mL
Solubility in ammonia 2.15 g/100 mL
Acidity (pKa) 6.7-7.3
Refractive index (nD) 1.5442 (589 nm)
Structure
Crystal structure Cubic (see text), cF8
Space group Fm3m, No. 225
Lattice constant a = 564.02 pm
Coordination
geometry Octahedral (Na+)
Octahedral (Cl−)
Hazards
MSDS External MSDS
EU Index Not listed
NFPA 704
NFPA 704.svg
0
1
0
Flash point Non-flammable
LD50 3000–8000 mg/kg (oral in rats, mice, rabbits)[1]
Related compounds
Other anions Sodium fluoride
Sodium bromide
Sodium iodide
Other cations Lithium chloride
Potassium chloride
Rubidium chloride
Caesium chloride
Supplementary data page
Structure and
properties n, εr, etc.
Thermodynamic
data Phase behaviour
Solid, liquid, gas
Spectral data UV, IR, NMR, MS
Yes check.svgY (what is this?) (verify)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references
Close up view of NaCl crystals.
Sodium chloride, also known as salt, common salt, table salt, or halite, is an ionic compound with the formula NaCl. Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multicellular organisms. As the major ingredient in edible salt, it is commonly used as a condiment and food preservative.
Contents
[hide]
* 1 Production and use
o 1.1 Synthetic uses
o 1.2 Biological uses
o 1.3 Optical uses
o 1.4 Optical data
o 1.5 Household uses
o 1.6 Firefighting uses
o 1.7 In weather
* 2 Biological functions
* 3 Crystal structure
* 4 Road salt
o 4.1 Additives
* 5 Alternative names
* 6 See also
* 7 References
* 8 Further reading
* 9 External links
[edit] Production and use
Salt is currently mass-produced by evaporation of seawater or brine from other sources, such as brine wells and salt lakes, and by mining rock salt, called halite. In 2002, world production was estimated at 210 million metric tons, the top five producers (in million tonnes) being the United States (40.3), China (32.9), Germany (17.7), India (14.5) and Canada (12.3).[2]
As well as the familiar uses of salt in cooking, salt is used in many applications, from manufacturing pulp and paper, to setting dyes in textiles and fabric, to producing soaps, detergents, and other bath products. It is the major source of industrial chlorine and sodium hydroxide, and used in almost every industry.
Sodium chloride is sometimes used as a cheap and safe desiccant because it appears to have hygroscopic properties, making salting an effective method of food preservation historically; as it draws water out of bacteria through osmotic pressure preventing them from reproducing and causing food to spoil. Even though more effective desiccants are available, few are safe for humans to ingest.
Israeli and Jordanian salt evaporation ponds at the south end of the Dead Sea.
Mounds of salt, Salar de Uyuni, Bolivia.
Modern rock salt mine near Mount Morris, New York, United States.
Evaporation lagoons, Aigues-Mortes, France.
Solubility of NaCl in various solvents
(g NaCl / 100 g of solvent at 25 °C)
H2O 36
Liquid ammonia 3.02
Methanol 1.4
Sulfolane 0.005
Formic acid 5.2
Acetone 0.000042
Formamide 9.4
Acetonitrile 0.0003
Dimethylformamide 0.04
Reference:
Burgess, J. Metal Ions in Solution
(Ellis Horwood, New York, 1978)
ISBN 0-85312-027-7
[edit] Synthetic uses
Sodium chloride is also the raw material used to produce chlorine which itself is required for sterilization and the production of many modern materials including PVC, pesticides and epoxy resins. Industrially, elemental chlorine is usually produced by the electrolysis of sodium chloride dissolved in water. Along with chlorine, this chloralkali process yields hydrogen gas and sodium hydroxide, according to the chemical equation
2NaCl + 2H2O → Cl2 + H2 + 2NaOH
Sodium metal is produced commercially through the electrolysis of liquid sodium chloride. This is now done in a Down's cell in which sodium chloride is mixed with calcium chloride to lower the melting point below 700 °C. As calcium is more electropositive than sodium, no calcium will be formed at the cathode. This method is less expensive than the previous method of electrolyzing sodium hydroxide.
Sodium chloride is used in other chemical processes for the large-scale production of compounds containing sodium or chlorine. In the Solvay process, sodium chloride is used for producing sodium carbonate and calcium chloride. In the Mannheim process and in the Hargreaves process, it is used for the production of sodium sulfate and hydrochloric acid.
[edit] Biological uses
Many micro organisms cannot live in an overly salty environment: water is drawn out of their cells by osmosis. For this reason salt is used to preserve some foods, such as smoked bacon or fish. It can also be used to detach leeches that have attached themselves to feed. It is also used to disinfect wounds.
[edit] Optical uses
Pure NaCl crystal is an optical compound with a wide transmission range from 200 nm to 20 um. It was often used in the infrared spectrum range and it is still used sometimes.
NaCl crystal is soft, hygroscopic and inexpensive. This limits its application to protected environment or for short term uses (prototyping). Exposed to free air NaCl optics will "rot".
Today tougher crystals like ZnSe are used instead of NaCl (for the IR spectral range).
[edit] Optical data
* Transmitivity: 92% (from 400 nm to 13μm)
* Refractive Index: 1.494 @ 10μm
* Reflection Loss: 7.5% @ 10μm (2 surfaces)
* dN/dT: -36.2 x 10-6/°C @ 0.7μm
Household uses
Since at least medieval times, people have used salt as a cleansing agent rubbed on household surfaces. It is also used in many brands of shampoo, and popularly to de-ice driveways and patches of ice.
At one time salt water was used to clean teeth.
[edit] Firefighting uses
A class D fire extinguisher for various metals
Sodium Chloride is the principal extinguishing agent in fire extinguishers (Met-L-X, Super D) used on combustible metal fires such as magnesium, potassium, sodium, and NaK alloys (Class D). Thermoplastic powder is added to the mixture, along with waterproofing (metal stearates) and anti-caking materials (tricalcium phosphate) to form the extinguishing agent. When it is applied to the fire, the salt acts like a heat sink, dissipating heat from the fire, and also forms an oxygen-excluding crust to smother the fire. The plastic additive melts and helps the crust maintain its integrity until the burning metal cools below its ignition temperature. This type of extinguisher was invented in the late 1940s in the cartridge-operated type shown here, although stored pressure versions are now popular. Common sizes are 30 lb. portable and 350 lb. wheeled.
[edit] In weather
Clouds above the Pacific
Small particles of sea salt are the dominant cloud condensation nuclei well out at sea, which allow the formation of clouds in otherwise non-polluted air.[3] Snow removal by addition of salt (salting) is done to make travel easier and safer, and decrease the long term impact of a heavy snowfall on human populations. This process is done by both individual households and by governments and institutions and utilizes salt as well as other chloride-based chemicals to eliminate snow from road surfaces and sidewalks.[4]
[edit] Biological functions
In humans, a high-salt intake has long been known to generally raise blood pressure, especially in certain individuals. More recently, it was demonstrated to attenuate nitric oxide production. Nitric oxide (NO) contributes to vessel homeostasis by inhibiting vascular smooth muscle contraction and growth, platelet aggregation, and leukocyte adhesion to the endothelium.[5][6]
[edit] Crystal structure
The crystal structure of sodium chloride. Each ion has six nearest neighbors, with octahedral geometry.
Main article: Cubic crystal system
Sodium chloride forms crystals with face-centered cubic symmetry. In these, the larger chloride ions, shown to the right as green spheres, are arranged in a cubic close-packing, while the smaller sodium ions, shown to the right as silver spheres, fill all the cubic gaps between them. Each ion is surrounded by six ions of the other kind; the surrounding ions are located at the vertices of a regular octahedron.
This same basic structure is found in many other minerals and is commonly known as the halite or rock-salt crystal structure. It can be represented as a face-centered cubic (fcc) lattice with a two atom basis. The first atom is located at each lattice point, and the second atom is located half way between lattice points along the fcc unit cell edge.
It is held together by an ionic bond which is produced by electrostatic forces arising from the difference in charge between the ions.
[edit] Road salt
Magnesium chloride
While salt was once a scarce commodity in history, industrialized production has now made salt plentiful. Approximately 51% of world output is now used by cold countries to de-ice roads in winter, both in grit bins and spread by winter service vehicles. Calcium chloride is preferred over sodium chloride, since CaCl2 releases energy upon forming a solution with water, heating any ice or snow it is in contact with. It also lowers the freezing point, depending on the concentration. NaCl does not release heat upon solution; however, it does lower the freezing point. It is also more readily available and does not have any special handling or storage requirements, unlike calcium chloride. The salinity (S) of water is measured as grams salt per kilogram (1000g) water, and the freezing temperatures are as follows.
S(g/kg) 0 10 20 24.7 30 35
T(freezing) (C) 0 -0.5 -1.08 -1.33 -1.63 -1.91
[edit] Additives
Most table salt sold for consumption today is not pure sodium chloride. In 1911 magnesium carbonate was first added to salt to make it flow more freely.[7] In 1924 trace amounts of iodine in form of sodium iodide, potassium iodide or potassium iodate were first added, to reduce the incidence of simple goiter.[8]
Salt for de-icing in the UK predominantly comes from a single mine in Winsford in Cheshire [[1]]. Prior to distribution it has an anti-caking agent added, sodium hexacyanoferrate(II) at less than 100ppm, this treatment enables rock salt to flow freely out of the gritting vehicles despite being stockpiled prior to use. In recent years this additive has also been used in table salt.
Alternative names
* NaCl, Sodium monochloride
* Table salt, Sal Culinare or Sal Culinaris
* Common Salt, Sal Commune
* Muriate of soda, Muriate of natrium, Chloride of Sodium, Hydrochlorate of Soda (older names)
* Sodii Chloridum, SodAe Hydro-chloras, SodAe Murias (ancient names)
* Nat Mur for Natrum Muriaticum, Natrum Muriatica, or even Natrium Muriate (homeopathic/Biochemic cell salts)
sulfhur
Sulphur
Big Photo
Cozzodisi Mine, Casteltermini, Agrigento Province, Sicily, Italy
© Peter Haas
Show Sulphur Photos (630)
Formula:
S
8
System: Orthorhombic Colour: Yellow, sulphur-yellow, ...
Lustre: Resinous, Greasy Hardness: 1½ - 2½
Name: From Middle English "sulphur", brimstone.
Dimorph of: Rosickýite
Sulphur Group.
Crystals are usually yellow to yellowish-brown blocky dipyramids, with thick tabular and disphenoidal crystals less common. Also found more typically as powdery yellow coatings. Native sulphur is usually formed from volcanic action - as a sublimate from volcanic gasses associated with realgar, cinnabar and other minerals. It is also found in some vein deposits and as an alteration product of sulphide minerals. It can also be formed biogenically.
NOTE: The American spelling is 'sulfur'.
Classification of Sulphur
IMA status: Valid - first described prior to 1959 (pre-IMA) - "Grandfathered"
Strunz 8th edition ID: 1/0.0-10
Nickel-Strunz 10th (pending) edition ID: 1.CC.05
1 : ELEMENTS (Metals and intermetallic alloys; metalloids and nonmetals; carbides, silicides, nitrides, phosphides)
C : Metalloids and Nonmetals
C : Sulfur-selenium-iodine
Dana 7th edition ID: 1.3.4.1
Dana 8th edition ID: 1.3.5.1
1 : NATIVE ELEMENTS AND ALLOYS
3 : Semi-metals and non-metals
Hey's CIM Ref.: 1.51
1 : Elements and Alloys (including the arsenides, antimonides and bismuthides of Cu, Ag and Au)
mindat.org URL: http://www.mindat.org/min-3826.html
Please feel free to link to this page.
Occurrences of Sulphur
Geological Setting: Usually formed from volcanic action - as a sublimate from volcanic gasses associated with realgar, cinnabar and other minerals. It is also found in some vein deposits and as an alteration product of sulphide minerals. It can also be formed biogenically - a major source being salt domes, where it has formed by the bacterial decomposition of calcium sulfate.
Physical Properties of Sulphur
Lustre: Resinous, Greasy
Diaphaneity (Transparency): Transparent, Translucent
Colour: Yellow, sulphur-yellow, brownish or greenish yellow, orange, white
Streak: Colourless
Hardness (Mohs): 1½ - 2½
Hardness Data: Measured
Tenacity: Brittle
Cleavage: Imperfect/Fair
Imperfect on {001}, {110} and {111}.
Parting: Parting on {111}
Fracture: Irregular/Uneven, Conchoidal
Comment: Also can be somewhat sectile
Density (measured): 2.07 g/cm3
Density (calculated): 2.076 g/cm3
Crystallography of Sulphur
Crystal System: Orthorhombic
Class (H-M): mmm (2/m 2/m 2/m) - Dipyramidal
Space Group: Fddd {F2/d 2/d 2/d}
Cell Parameters: a = 10.468Å, b = 12.870Å, c = 24.49Å
Ratio: a:b:c = 0.813 : 1 : 1.903
Unit Cell Volume: V 3,299.37 ų (Calculated from Unit Cell)
Z: 128
Morphology: Over 50 forms have been noted, blocky dipyramidal ones most common, also tabular and sphenoidal; also found as powdery coatings, massive material, and in reniform and stalactic forms.
Twinning: On {101}{011}{110} rare.
Crystal Atlas:
Image Loading
Click on an icon to view
Sulfur no.1 - Goldschmidt (1913-1926)
Sulfur no.8 - Goldschmidt (1913-1926)
Sulfur no.81 - Goldschmidt (1913-1926)
Sulfur no.116 - Goldschmidt (1913-1926)
About Crystal Atlas
You may need to scroll this box using your mouse to view the full instructions.
The mindat.org Crystal Atlas allows you to view a selection of crystal drawings of real and idealised crystal forms for this mineral and, in certain cases, 3d rotating crystal objects. You need Java to see these. You can download Java for free - click here to download Java
The 3d models and java code are kindly provided by www.smorf.nl. You can control the movement of the models by holding down the left mouse-button over the 3d model and moving your mouse. Keyboard controls are:
: default positions
t/T : decrease/increase transparency x/X : next/previous texture
b/B : next/previous background w : toggle wireframe
s : toggle sticks m : toggle miller indices
k : toggle crystallographic axes =/- : zoom in/out
r : stop/start rotation 1/2/3
X-Ray Powder Diffraction:
Image Loading
Radiation - Copper Kα
Data Set:
Horizontal Axis: ° to ° Vertical Axis: % Source Data: Filtered Data: Peaks:
Data courtesy of RRUFF project at University of Arizona, used with permission.
X-Ray Powder Diffraction:
d-spacing Intensity
3.85 (100)
3.44 (40)
3.33 (30)
3.21 (60)
3.11 (30)
3.08 (20)
2.84 (20)
2.62 (10)
Comments: Data given are for synthetic mateiral.
Optical Data of Sulphur
Type: Biaxial (+)
RI values: nα = 1.958 nβ = 2.038 nγ = 2.245
2V: Measured: 68° , Calculated: 70°
Maximum Birefringence: δ = 0.287
Chart shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief: Very High
Dispersion: relatively weak r< v
Pleochroism: Visible
Chemical Properties of Sulphur
Formula:
S
8
Essential elements: S
All elements listed in formula: S
Analytical Data: Sulfur, orthorhombic, is alpha-S, while rosickyite, monoclinic, is gamma-S.
Common Impurities: Se,Te
Relationship of Sulphur to other Species
Member of Group:
Sulphur Group :
Related Minerals - Nickel-Strunz Grouping):
- +
1.CC.05 Rosickýite
S
1.CC.10 Selenium
Se
1.CC.10 Tellurium
Te
Related Minerals - Hey's Index Grouping:
- +
1.1 Copper
Cu
1.2 Silver
Ag
1.5 Gold
Au
1.6 Auricupride
Cu
3
Au
1.7 Tetra-auricupride
AuCu
1.8 Zinc
Zn
1.9 Cadmium
Cd
1.10 Danbaite
CuZn
2
1.11 Zhanghengite
CuZn
1.12 Mercury
Hg
1.13 Kolymite
Cu
7
Hg
6
1.14 Moschellandsbergite
Ag
2
Hg
3
1.15 Eugenite
Ag
11
Hg
2
1.16 Schachnerite
Ag
1.1
Hg
0.9
1.17 Paraschachnerite
Ag
3
Hg
2
1.18 Luanheite
Ag
3
Hg
1.19 Weishanite
(Au,Ag)
3
Hg
2
1.20 Indium
In
1.21 Aluminium
Al
1.22 Khatyrkite
(Cu,Zn)Al
2
1.23 Cupalite
(Cu,Zn)Al
1.24 Diamond
C
1.25 Graphite
C
1.26 Chaoite
C
1.27 Lonsdaleite
C
1.28 Silicon
Si
1.29 Tin
Sn
1.30 Lead
Pb
1.31 Anyuiite
Au(Pb,Sb)
2
1.31 Novodneprite
AuPb
3
1.32 Leadamalgam
HgPb
2
1.33 Arsenic
As
1.34 Arsenolamprite
As
1.35 Paxite
CuAs
2
1.36 Koutekite
Cu
5
As
2
1.37 Domeykite
Cu
3
As
1.38 Algodonite
(Cu
1-x
As
x
)
1.39 Novakite
Cu
20
AgAs
10
1.40 Kutinaite
Cu
2
AgAs
1.41 Antimony
Sb
1.42 Stibarsen
AsSb
1.43 Paradocrasite
Sb
3
As
1.44 Horsfordite
1.45 Cuprostibite
Cu
2
(Sb,Tl)
1.46 Allargentum
(Ag
1-x
Sb
x
)
1.47 Aurostibite
AuSb
2
1.48 Dyscrasite
Ag
3
Sb
1.49 Bismuth
Bi
1.50 Maldonite
Au
2
Bi
1.52 Rosickýite
S
1.53 Selenium
Se
1.54 Tellurium
Te
1.55 Chromium
Cr
1.56 Rhenium
Re
1.57 Iron
Fe
1.58 Chromferide
Fe
3
Cr
1-x
(x=0.6)
1.59 Ferchromide
Cr
1.5
Fe
0.5-x
1.60 Wairauite
CoFe
1.61 Nickel
Ni
1.62 Kamacite
(Fe,Ni)
1.63 Taenite
(Fe,Ni)
1.64 Tetrataenite
FeNi
1.65 Awaruite
Ni
3
Fe
1.66 Palladium
(Pd,Pt)
1.67 Potarite
PdHg
1.68 Paolovite
Pd
2
Sn
1.69 Stannopalladinite
(Pd,Cu)
3
Sn
2
1.70 Cabriite
Pd
2
SnCu
1.71 Taimyrite
(Pd,Cu,Pt)
3
Sn
1.72 Atokite
(Pd,Pt)
3
Sn
1.73 Rustenburgite
(Pt,Pd)
3
Sn
1.74 Zvyagintsevite
(Pd,Pt,Au)
3
(Pb,Sn)
1.75 Plumbopalladinite
Pd
3
Pb
2
1.76 Osmium
(Os,Ir,Ru)
1.77 Iridium
(Ir,Os,Ru)
1.82 Platinum
Pt
1.83 Hongshiite
PtCu
1.84 Niggliite
PtSn
1.85 Isoferroplatinum
Pt
3
Fe
1.86 Tetraferroplatinum
PtFe
1.87 Tulameenite
Pt
2
CuFe
1.88 Ferronickelplatinum
Pt
2
FeNi
1.89 Rhodium
(Rh,Pt)
Related Minerals - Dana Grouping):
- +
1.3.4.2 Rosickýite
S
Other Names for Sulphur
Synonyms:
Alpha-Sulfur Alpha-Sulphur α-Sulfur a-Sulphur α-Sulphur
Brimstone Native S Native Sulfur Native Sulphur Sulfur-α
Sulfur-alpha Sulphur-α Sulphur-alpha
Other Languages:
Afrikaans: Swawel
Albanian: Squfuri
Arabic: كبريت
Armenian: Ծծումբ
Asturian: Azufre
Aymara: Asuphri
Azeri: Kükürd
Basque: Sufre
Belarusian: Сера
Bengali: গন্ধক
Bosnian (Latin Script): Sumpor
Bulgarian: Сяра
Catalan: Sofre
Corsican: Zolfu
Croatian: Sumpor
Czech: Síra
Danish: Svovl
Dutch: Zwavel
Erzya: Палыкандал
Esperanto: Sulfuro
Estonian: Väävel
Finnish: Rikki
French: Soufre
Friulian: Solfar
Galician: Xofre
German: Schwefel
Gediegen Schwefel
Greek: Θείο
Guarani: Itaysy
Haitian: Souf
Hakka: Liù-vòng
Hebrew: גופרית
Hindi: गन्धक
Hungarian: Kén
Icelandic: Brennisteinn
Ido: Sulfo
Indonesian: Belerang
Irish Gaelic: Sulfar
Italian: Zolfo
Solfo
Japanese: 硫黄
Javanese: Welirang
Kannada: ಗಂಧಕ
Korean: 황
Kurdish (Latin Script): Kibrît
Latin: Sulphur
Latvian: Sērs
Limburgian: Solfer
Lithuanian: Siera
Lojban: sliri
Low Saxon: Swevel
Luxembourgish: Schwiefel
Macedonian: Сулфур
Malayalam: ഗന്ധകം
Manx: Sulfur
Maori: Pungatara
Marathi: सल्फर
Mongolian (Cyrillic Script): Хүхэр
Nahuatl: Tlequiquiztlālli
Norwegian (Bokmål): Svovel
Norwegian (Nynorsk): Svovel
Novial: Sulfre
Occitan: Sofre
Persian: گوگرد
Polish: Siarka
Portuguese: Enxofre
Quechua: Salina
Romanian: Sulf
Russian: Сера
Serbian (Cyrillic Script): Сумпор
Serbo-Croatian: Sumpor
Sicilian: Sùrfuru
Simplified Chinese: 硫
Slovak: Síra
Slovenian: Žveplo
Spanish: Azufre
Sundanese: Walirang
Swahili: Sulfuri
Swedish: Svavel
Tamil: கந்தகம்
Telugu: గంధకము
Thai: กำมะถัน
Traditional Chinese: 硫
Turkish: Kükürt
Ukrainian: Сірка
Upper Sorbian: Syrik
Uzbek (Latin Script): Oltingugurt
Vietnamese: Lưu huỳnh
Welsh: Sylffwr
West Flemish: Sulfer
Yiddish: שװעבל
Varieties:
Selenian Sulphur
Other Information
Thermal Behaviour: With a low melting point of 113 degrees C. sulphur burns readily in air, with a low blue flame, and gives off choking fumes of sulphur-dioxide - acrid odor (forms sulferous and eventually sulfuric acid in air).
Health Warning: No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Industrial Uses: Used in a great many applications, ranging from matches and fireworks to rubber.
References for Sulphur
Reference List: Palache, Charles, Harry Berman & Clifford Frondel (1944), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Volume I: Elements, Sulfides, Sulfosalts, Oxides. John Wiley and Sons, Inc., New York. 7th edition, revised and enlarged, 834pp.: 140-144.
Ventriglia U. – (1951) Sulla struttura dello zolfo rombico. Periodico di Mineralogia – Roma pp. 237-255.
Acta Crystallographica (1987): C43: 2260-2262.
Gaines, Richard V., H. Catherine, W. Skinner, Eugene E. Foord, Brian Mason, Abraham Rosenzweig (1997), Dana's New Mineralogy : The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana: 30.
Internet Links for Sulphur
Search Engines:
# Look for Sulphur on Google
# Look for Sulphur images on Google
# External Links: Look for Sulphur on Webmineral
# Look for Sulphur on Athena Mineralogy
# Look for Sulphur on Wikipedia
# Look for Sulphur on Mineralien Atlas
# Raman and XRD data at RRUFF project
# American Mineralogist Crystal Structure Database
# Search for Sulphur in the Natural History Museum (London) online catalogue
# Mineral Dealers: Buy from David K Joyce minerals
# Buy Fine Minerals from mineralsweb.com
# Fine Minerals from Dan Weinrich Minerals
# Wilensky Fine Minerals
# Buy RARE Minerals from Rocks of Africa
# The Arkenstone - Fine Minerals
# Search for - Sulphur - on e-Rocks Mineral Sales & Auctions
# rare and unusual minerals mainly crystallized
# Minerals from Stenbutikken Rock Shop
# Top quality minerals from Kristalle of California
# Fabre Minerals - search for Sulphur specimens
# DAKOTA MATRIX offers Cabinet and Rare Species from Worldwide Localities.
# Jobs: Mining & Geology Jobs
Page Sponsor
Sponsorship: This page is currently not sponsored. Click here to sponsor this page.
Localities for Sulphur
[Tsumeb Mine (Tsumcorp Mine), Tsumeb, Otjikoto (Oshikoto) Region, Namibia] [Urucum mine (Tim mine; Córrego do Urucum pegmatite), Galiléia, Doce valley, Minas Gerais, Southeast Region, Brazil] [Nanisivik Mine, Nanisivik, Baffin Island, Nunavut Territory, Canada] [Sulphur Springs, Soufriere, Saint Lucia] [Nyamuragira volcano (Nyamlagira), Kivu, Democratic Republic of Congo (Zaïre)] [Pueblo Viejo Mine, Cotuí, Sánchez Ramírez Province, Dominican Republic] [Polaris Mine (Arvik Mine), Little Cornwallis Island, Nunavut Territory, Canada]
Syarat Penggunaan
Peta
Satelit
Hibrida
Medan
USA Topo
5000 mi
5000 km
Show Locality List (1368 Items)
The map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
Big Photo
Cozzodisi Mine, Casteltermini, Agrigento Province, Sicily, Italy
© Peter Haas
Show Sulphur Photos (630)
Formula:
S
8
System: Orthorhombic Colour: Yellow, sulphur-yellow, ...
Lustre: Resinous, Greasy Hardness: 1½ - 2½
Name: From Middle English "sulphur", brimstone.
Dimorph of: Rosickýite
Sulphur Group.
Crystals are usually yellow to yellowish-brown blocky dipyramids, with thick tabular and disphenoidal crystals less common. Also found more typically as powdery yellow coatings. Native sulphur is usually formed from volcanic action - as a sublimate from volcanic gasses associated with realgar, cinnabar and other minerals. It is also found in some vein deposits and as an alteration product of sulphide minerals. It can also be formed biogenically.
NOTE: The American spelling is 'sulfur'.
Classification of Sulphur
IMA status: Valid - first described prior to 1959 (pre-IMA) - "Grandfathered"
Strunz 8th edition ID: 1/0.0-10
Nickel-Strunz 10th (pending) edition ID: 1.CC.05
1 : ELEMENTS (Metals and intermetallic alloys; metalloids and nonmetals; carbides, silicides, nitrides, phosphides)
C : Metalloids and Nonmetals
C : Sulfur-selenium-iodine
Dana 7th edition ID: 1.3.4.1
Dana 8th edition ID: 1.3.5.1
1 : NATIVE ELEMENTS AND ALLOYS
3 : Semi-metals and non-metals
Hey's CIM Ref.: 1.51
1 : Elements and Alloys (including the arsenides, antimonides and bismuthides of Cu, Ag and Au)
mindat.org URL: http://www.mindat.org/min-3826.html
Please feel free to link to this page.
Occurrences of Sulphur
Geological Setting: Usually formed from volcanic action - as a sublimate from volcanic gasses associated with realgar, cinnabar and other minerals. It is also found in some vein deposits and as an alteration product of sulphide minerals. It can also be formed biogenically - a major source being salt domes, where it has formed by the bacterial decomposition of calcium sulfate.
Physical Properties of Sulphur
Lustre: Resinous, Greasy
Diaphaneity (Transparency): Transparent, Translucent
Colour: Yellow, sulphur-yellow, brownish or greenish yellow, orange, white
Streak: Colourless
Hardness (Mohs): 1½ - 2½
Hardness Data: Measured
Tenacity: Brittle
Cleavage: Imperfect/Fair
Imperfect on {001}, {110} and {111}.
Parting: Parting on {111}
Fracture: Irregular/Uneven, Conchoidal
Comment: Also can be somewhat sectile
Density (measured): 2.07 g/cm3
Density (calculated): 2.076 g/cm3
Crystallography of Sulphur
Crystal System: Orthorhombic
Class (H-M): mmm (2/m 2/m 2/m) - Dipyramidal
Space Group: Fddd {F2/d 2/d 2/d}
Cell Parameters: a = 10.468Å, b = 12.870Å, c = 24.49Å
Ratio: a:b:c = 0.813 : 1 : 1.903
Unit Cell Volume: V 3,299.37 ų (Calculated from Unit Cell)
Z: 128
Morphology: Over 50 forms have been noted, blocky dipyramidal ones most common, also tabular and sphenoidal; also found as powdery coatings, massive material, and in reniform and stalactic forms.
Twinning: On {101}{011}{110} rare.
Crystal Atlas:
Image Loading
Click on an icon to view
Sulfur no.1 - Goldschmidt (1913-1926)
Sulfur no.8 - Goldschmidt (1913-1926)
Sulfur no.81 - Goldschmidt (1913-1926)
Sulfur no.116 - Goldschmidt (1913-1926)
About Crystal Atlas
You may need to scroll this box using your mouse to view the full instructions.
The mindat.org Crystal Atlas allows you to view a selection of crystal drawings of real and idealised crystal forms for this mineral and, in certain cases, 3d rotating crystal objects. You need Java to see these. You can download Java for free - click here to download Java
The 3d models and java code are kindly provided by www.smorf.nl. You can control the movement of the models by holding down the left mouse-button over the 3d model and moving your mouse. Keyboard controls are:
: default positions
t/T : decrease/increase transparency x/X : next/previous texture
b/B : next/previous background w : toggle wireframe
s : toggle sticks m : toggle miller indices
k : toggle crystallographic axes =/- : zoom in/out
r : stop/start rotation 1/2/3
X-Ray Powder Diffraction:
Image Loading
Radiation - Copper Kα
Data Set:
Horizontal Axis: ° to ° Vertical Axis: % Source Data: Filtered Data: Peaks:
Data courtesy of RRUFF project at University of Arizona, used with permission.
X-Ray Powder Diffraction:
d-spacing Intensity
3.85 (100)
3.44 (40)
3.33 (30)
3.21 (60)
3.11 (30)
3.08 (20)
2.84 (20)
2.62 (10)
Comments: Data given are for synthetic mateiral.
Optical Data of Sulphur
Type: Biaxial (+)
RI values: nα = 1.958 nβ = 2.038 nγ = 2.245
2V: Measured: 68° , Calculated: 70°
Maximum Birefringence: δ = 0.287
Chart shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief: Very High
Dispersion: relatively weak r< v
Pleochroism: Visible
Chemical Properties of Sulphur
Formula:
S
8
Essential elements: S
All elements listed in formula: S
Analytical Data: Sulfur, orthorhombic, is alpha-S, while rosickyite, monoclinic, is gamma-S.
Common Impurities: Se,Te
Relationship of Sulphur to other Species
Member of Group:
Sulphur Group :
Related Minerals - Nickel-Strunz Grouping):
- +
1.CC.05 Rosickýite
S
1.CC.10 Selenium
Se
1.CC.10 Tellurium
Te
Related Minerals - Hey's Index Grouping:
- +
1.1 Copper
Cu
1.2 Silver
Ag
1.5 Gold
Au
1.6 Auricupride
Cu
3
Au
1.7 Tetra-auricupride
AuCu
1.8 Zinc
Zn
1.9 Cadmium
Cd
1.10 Danbaite
CuZn
2
1.11 Zhanghengite
CuZn
1.12 Mercury
Hg
1.13 Kolymite
Cu
7
Hg
6
1.14 Moschellandsbergite
Ag
2
Hg
3
1.15 Eugenite
Ag
11
Hg
2
1.16 Schachnerite
Ag
1.1
Hg
0.9
1.17 Paraschachnerite
Ag
3
Hg
2
1.18 Luanheite
Ag
3
Hg
1.19 Weishanite
(Au,Ag)
3
Hg
2
1.20 Indium
In
1.21 Aluminium
Al
1.22 Khatyrkite
(Cu,Zn)Al
2
1.23 Cupalite
(Cu,Zn)Al
1.24 Diamond
C
1.25 Graphite
C
1.26 Chaoite
C
1.27 Lonsdaleite
C
1.28 Silicon
Si
1.29 Tin
Sn
1.30 Lead
Pb
1.31 Anyuiite
Au(Pb,Sb)
2
1.31 Novodneprite
AuPb
3
1.32 Leadamalgam
HgPb
2
1.33 Arsenic
As
1.34 Arsenolamprite
As
1.35 Paxite
CuAs
2
1.36 Koutekite
Cu
5
As
2
1.37 Domeykite
Cu
3
As
1.38 Algodonite
(Cu
1-x
As
x
)
1.39 Novakite
Cu
20
AgAs
10
1.40 Kutinaite
Cu
2
AgAs
1.41 Antimony
Sb
1.42 Stibarsen
AsSb
1.43 Paradocrasite
Sb
3
As
1.44 Horsfordite
1.45 Cuprostibite
Cu
2
(Sb,Tl)
1.46 Allargentum
(Ag
1-x
Sb
x
)
1.47 Aurostibite
AuSb
2
1.48 Dyscrasite
Ag
3
Sb
1.49 Bismuth
Bi
1.50 Maldonite
Au
2
Bi
1.52 Rosickýite
S
1.53 Selenium
Se
1.54 Tellurium
Te
1.55 Chromium
Cr
1.56 Rhenium
Re
1.57 Iron
Fe
1.58 Chromferide
Fe
3
Cr
1-x
(x=0.6)
1.59 Ferchromide
Cr
1.5
Fe
0.5-x
1.60 Wairauite
CoFe
1.61 Nickel
Ni
1.62 Kamacite
(Fe,Ni)
1.63 Taenite
(Fe,Ni)
1.64 Tetrataenite
FeNi
1.65 Awaruite
Ni
3
Fe
1.66 Palladium
(Pd,Pt)
1.67 Potarite
PdHg
1.68 Paolovite
Pd
2
Sn
1.69 Stannopalladinite
(Pd,Cu)
3
Sn
2
1.70 Cabriite
Pd
2
SnCu
1.71 Taimyrite
(Pd,Cu,Pt)
3
Sn
1.72 Atokite
(Pd,Pt)
3
Sn
1.73 Rustenburgite
(Pt,Pd)
3
Sn
1.74 Zvyagintsevite
(Pd,Pt,Au)
3
(Pb,Sn)
1.75 Plumbopalladinite
Pd
3
Pb
2
1.76 Osmium
(Os,Ir,Ru)
1.77 Iridium
(Ir,Os,Ru)
1.82 Platinum
Pt
1.83 Hongshiite
PtCu
1.84 Niggliite
PtSn
1.85 Isoferroplatinum
Pt
3
Fe
1.86 Tetraferroplatinum
PtFe
1.87 Tulameenite
Pt
2
CuFe
1.88 Ferronickelplatinum
Pt
2
FeNi
1.89 Rhodium
(Rh,Pt)
Related Minerals - Dana Grouping):
- +
1.3.4.2 Rosickýite
S
Other Names for Sulphur
Synonyms:
Alpha-Sulfur Alpha-Sulphur α-Sulfur a-Sulphur α-Sulphur
Brimstone Native S Native Sulfur Native Sulphur Sulfur-α
Sulfur-alpha Sulphur-α Sulphur-alpha
Other Languages:
Afrikaans: Swawel
Albanian: Squfuri
Arabic: كبريت
Armenian: Ծծումբ
Asturian: Azufre
Aymara: Asuphri
Azeri: Kükürd
Basque: Sufre
Belarusian: Сера
Bengali: গন্ধক
Bosnian (Latin Script): Sumpor
Bulgarian: Сяра
Catalan: Sofre
Corsican: Zolfu
Croatian: Sumpor
Czech: Síra
Danish: Svovl
Dutch: Zwavel
Erzya: Палыкандал
Esperanto: Sulfuro
Estonian: Väävel
Finnish: Rikki
French: Soufre
Friulian: Solfar
Galician: Xofre
German: Schwefel
Gediegen Schwefel
Greek: Θείο
Guarani: Itaysy
Haitian: Souf
Hakka: Liù-vòng
Hebrew: גופרית
Hindi: गन्धक
Hungarian: Kén
Icelandic: Brennisteinn
Ido: Sulfo
Indonesian: Belerang
Irish Gaelic: Sulfar
Italian: Zolfo
Solfo
Japanese: 硫黄
Javanese: Welirang
Kannada: ಗಂಧಕ
Korean: 황
Kurdish (Latin Script): Kibrît
Latin: Sulphur
Latvian: Sērs
Limburgian: Solfer
Lithuanian: Siera
Lojban: sliri
Low Saxon: Swevel
Luxembourgish: Schwiefel
Macedonian: Сулфур
Malayalam: ഗന്ധകം
Manx: Sulfur
Maori: Pungatara
Marathi: सल्फर
Mongolian (Cyrillic Script): Хүхэр
Nahuatl: Tlequiquiztlālli
Norwegian (Bokmål): Svovel
Norwegian (Nynorsk): Svovel
Novial: Sulfre
Occitan: Sofre
Persian: گوگرد
Polish: Siarka
Portuguese: Enxofre
Quechua: Salina
Romanian: Sulf
Russian: Сера
Serbian (Cyrillic Script): Сумпор
Serbo-Croatian: Sumpor
Sicilian: Sùrfuru
Simplified Chinese: 硫
Slovak: Síra
Slovenian: Žveplo
Spanish: Azufre
Sundanese: Walirang
Swahili: Sulfuri
Swedish: Svavel
Tamil: கந்தகம்
Telugu: గంధకము
Thai: กำมะถัน
Traditional Chinese: 硫
Turkish: Kükürt
Ukrainian: Сірка
Upper Sorbian: Syrik
Uzbek (Latin Script): Oltingugurt
Vietnamese: Lưu huỳnh
Welsh: Sylffwr
West Flemish: Sulfer
Yiddish: שװעבל
Varieties:
Selenian Sulphur
Other Information
Thermal Behaviour: With a low melting point of 113 degrees C. sulphur burns readily in air, with a low blue flame, and gives off choking fumes of sulphur-dioxide - acrid odor (forms sulferous and eventually sulfuric acid in air).
Health Warning: No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Industrial Uses: Used in a great many applications, ranging from matches and fireworks to rubber.
References for Sulphur
Reference List: Palache, Charles, Harry Berman & Clifford Frondel (1944), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Volume I: Elements, Sulfides, Sulfosalts, Oxides. John Wiley and Sons, Inc., New York. 7th edition, revised and enlarged, 834pp.: 140-144.
Ventriglia U. – (1951) Sulla struttura dello zolfo rombico. Periodico di Mineralogia – Roma pp. 237-255.
Acta Crystallographica (1987): C43: 2260-2262.
Gaines, Richard V., H. Catherine, W. Skinner, Eugene E. Foord, Brian Mason, Abraham Rosenzweig (1997), Dana's New Mineralogy : The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana: 30.
Internet Links for Sulphur
Search Engines:
# Look for Sulphur on Google
# Look for Sulphur images on Google
# External Links: Look for Sulphur on Webmineral
# Look for Sulphur on Athena Mineralogy
# Look for Sulphur on Wikipedia
# Look for Sulphur on Mineralien Atlas
# Raman and XRD data at RRUFF project
# American Mineralogist Crystal Structure Database
# Search for Sulphur in the Natural History Museum (London) online catalogue
# Mineral Dealers: Buy from David K Joyce minerals
# Buy Fine Minerals from mineralsweb.com
# Fine Minerals from Dan Weinrich Minerals
# Wilensky Fine Minerals
# Buy RARE Minerals from Rocks of Africa
# The Arkenstone - Fine Minerals
# Search for - Sulphur - on e-Rocks Mineral Sales & Auctions
# rare and unusual minerals mainly crystallized
# Minerals from Stenbutikken Rock Shop
# Top quality minerals from Kristalle of California
# Fabre Minerals - search for Sulphur specimens
# DAKOTA MATRIX offers Cabinet and Rare Species from Worldwide Localities.
# Jobs: Mining & Geology Jobs
Page Sponsor
Sponsorship: This page is currently not sponsored. Click here to sponsor this page.
Localities for Sulphur
[Tsumeb Mine (Tsumcorp Mine), Tsumeb, Otjikoto (Oshikoto) Region, Namibia] [Urucum mine (Tim mine; Córrego do Urucum pegmatite), Galiléia, Doce valley, Minas Gerais, Southeast Region, Brazil] [Nanisivik Mine, Nanisivik, Baffin Island, Nunavut Territory, Canada] [Sulphur Springs, Soufriere, Saint Lucia] [Nyamuragira volcano (Nyamlagira), Kivu, Democratic Republic of Congo (Zaïre)] [Pueblo Viejo Mine, Cotuí, Sánchez Ramírez Province, Dominican Republic] [Polaris Mine (Arvik Mine), Little Cornwallis Island, Nunavut Territory, Canada]
Syarat Penggunaan
Peta
Satelit
Hibrida
Medan
USA Topo
5000 mi
5000 km
Show Locality List (1368 Items)
The map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
reversible reaction
reversible reaction
Chemical reaction that proceeds in both directions at the same time, as the product decomposes back into reactants as it is being produced. Such reactions do not run to completion, provided that no substance leaves the system. Examples include the manufacture of ammonia from hydrogen and nitrogen, and the oxidation of sulphur dioxide to sulphur trioxide.
N2 + 3H2 ⇌ 2NH3
2SO2 + O2 ⇌ 2SO3
The term is also applied to those reactions that can be made to go in the opposite direction by changing the conditions, but these run to completion because some of the substances escape from the reaction. Examples are the decomposition of calcium hydrogencarbonate on heating and the loss of water of crystallization by copper(II) sulphate pentahydrate.
Ca(HCO3)2(aq) → CaCO3(s) + CO2(g) + H2O(l)
CuSO4.5H2O(s) → CuSO4(s) + 5H2O(g)
Chemical reaction that proceeds in both directions at the same time, as the product decomposes back into reactants as it is being produced. Such reactions do not run to completion, provided that no substance leaves the system. Examples include the manufacture of ammonia from hydrogen and nitrogen, and the oxidation of sulphur dioxide to sulphur trioxide.
N2 + 3H2 ⇌ 2NH3
2SO2 + O2 ⇌ 2SO3
The term is also applied to those reactions that can be made to go in the opposite direction by changing the conditions, but these run to completion because some of the substances escape from the reaction. Examples are the decomposition of calcium hydrogencarbonate on heating and the loss of water of crystallization by copper(II) sulphate pentahydrate.
Ca(HCO3)2(aq) → CaCO3(s) + CO2(g) + H2O(l)
CuSO4.5H2O(s) → CuSO4(s) + 5H2O(g)
reversible reaction
reversible reaction
Chemical reaction that proceeds in both directions at the same time, as the product decomposes back into reactants as it is being produced. Such reactions do not run to completion, provided that no substance leaves the system. Examples include the manufacture of ammonia from hydrogen and nitrogen, and the oxidation of sulphur dioxide to sulphur trioxide.
N2 + 3H2 ⇌ 2NH3
2SO2 + O2 ⇌ 2SO3
The term is also applied to those reactions that can be made to go in the opposite direction by changing the conditions, but these run to completion because some of the substances escape from the reaction. Examples are the decomposition of calcium hydrogencarbonate on heating and the loss of water of crystallization by copper(II) sulphate pentahydrate.
Ca(HCO3)2(aq) → CaCO3(s) + CO2(g) + H2O(l)
CuSO4.5H2O(s) → CuSO4(s) + 5H2O(g)
Chemical reaction that proceeds in both directions at the same time, as the product decomposes back into reactants as it is being produced. Such reactions do not run to completion, provided that no substance leaves the system. Examples include the manufacture of ammonia from hydrogen and nitrogen, and the oxidation of sulphur dioxide to sulphur trioxide.
N2 + 3H2 ⇌ 2NH3
2SO2 + O2 ⇌ 2SO3
The term is also applied to those reactions that can be made to go in the opposite direction by changing the conditions, but these run to completion because some of the substances escape from the reaction. Examples are the decomposition of calcium hydrogencarbonate on heating and the loss of water of crystallization by copper(II) sulphate pentahydrate.
Ca(HCO3)2(aq) → CaCO3(s) + CO2(g) + H2O(l)
CuSO4.5H2O(s) → CuSO4(s) + 5H2O(g)
redox reaction
Redox Reactions
Redox reactions, or oxidation-reduction reactions, have a number of similarities to acid-base reactions. Fundamentally, redox reactions are a family of reactions that are concerned with the transfer of electrons between species. Like acid-base reactions, redox reactions are a matched set -- you don't have an oxidation reaction without a reduction reaction happening at the same time. Oxidation refers to the loss of electrons, while reduction refers to the gain of electrons. Each reaction by itself is called a "half-reaction", simply because we need two (2) half-reactions to form a whole reaction. In notating redox reactions, chemists typically write out the electrons explicitly:
Cu (s) ----> Cu2+ + 2 e-
This half-reaction says that we have solid copper (with no charge) being oxidized (losing electrons) to form a copper ion with a plus 2 charge. Notice that, like the stoichiometry notation, we have a "balance" between both sides of the reaction. We have one (1) copper atom on both sides, and the charges balance as well. The symbol "e-" represents a free electron with a negative charge that can now go out and reduce some other species, such as in the half-reaction:
2 Ag+ (aq) + 2 e- ------> 2 Ag (s)
Here, two silver ions (silver with a positive charge) are being reduced through the addition of two (2) electrons to form solid silver. The abbreviations "aq" and "s" mean aqueous and solid, respectively. We can now combine the two (2) half-reactions to form a redox equation:
We can also discuss the individual components of these reactions as follows. If a chemical causes another substance to be oxidized, we call it the oxidizing agent. In the equation above, Ag+ is the oxidizing agent, because it causes Cu(s) to lose electrons. Oxidants get reduced in the process by a reducing agent. Cu(s) is, naturally, the reducing agent in this case, as it causes Ag+ to gain electrons.
As a summary, here are the steps to follow to balance a redox equation in acidic medium (add the starred step in a basic medium):
1. Divide the equation into an oxidation half-reaction and a reduction half-reaction
2. Balance these
* Balance the elements other than H and O
* Balance the O by adding H2O
* Balance the H by adding H+
* Balance the charge by adding e-
3. Multiply each half-reaction by an integer such that the number of e- lost in one equals the number gained in the other
4. Combine the half-reactions and cancel
5. **Add OH- to each side until all H+ is gone and then cancel again**
In considering redox reactions, you must have some sense of the oxidation number (ON) of the compound. The oxidation number is defined as the effective charge on an atom in a compound, calculated according to a prescribed set of rules. An increase in oxidation number corresponds to oxidation, and a decrease to reduction. The oxidation number of a compound has some analogy to the pH and pK measurements found in acids and bases -- the oxidation number suggests the strength or tendency of the compound to be oxidized or reduced, to serve as an oxidizing agent or reducing agent. The rules are shown below. Go through them in the order given until you have an oxidation number assigned.
1. For atoms in their elemental form, the oxidation number is 0
2. For ions, the oxidation number is equal to their charge
3. For single hydrogen, the number is usually +1 but in some cases it is -1
4. For oxygen, the number is usually -2
5. The sum of the oxidation number (ONs) of all the atoms in the molecule or ion is equal to its total charge.
As a side note, the term "oxidation", with its obvious root from the word "oxygen", assumes that oxygen has an oxidation number of -2. Using this as a benchmark, oxidation numbers were assigned to all other elements. For example, if we look at H2O, and assign the value of -2 to the oxygen atom, the hydrogens must each have an oxidation number of +1 by default, since water is a neutral molecule. As an example, what is the oxidation number of sulfur in sulfur dioxide (SO2)? Given that each oxygen atom has a -2 charge, and knowing that the molecule is neutral, the oxidation number for sulfur must be +4. What about for a sulfate ion (SO4 with a total charge of -2)? Again, the charge of all the oxygen atoms is 4 x -2 = -8. Sulfur must then have an oxidation number of +6, since +6 + (-8) = -2, the total charge on the ion. Since the sulfur in sulfate has a higher oxidation number than in sulfur dioxide, it is said to be more highly oxidized.
Working with redox reactions is fundamentally a bookkeeping issue. You need to be able to account for all of the electrons as they transfer from one species to another. There are a number of rules and tricks for balancing redox reactions, but basically they all boil down to dealing with each of the two half-reactions individually. Consider for example the reaction of aluminum metal to form alumina (Al2O3). The unbalanced reaction is as follows:
Looking at each half reaction separately:
This reaction shows aluminum metal being oxidized to form an aluminum ion with a +3 charge. The half-reaction below shows oxygen being reduced to form two (2) oxygen ions, each with a charge of -2.
If we combine those two (2) half-reactions, we must make the number of electrons equal on both sides. The number 12 is a common multiple of three (3) and four (4), so we multiply the aluminum reaction by four (4) and the oxygen reaction by three (3) to get 12 electrons on both sides. Now, simply combine the reactions. Notice that we have 12 electrons on both sides, which cancel out. The final step is to combine the aluminum and oxygen ions on the right side using a cross multiply technique:
Taking care of the number of atoms, you should end up with:
One of the more useful calculations in redox reactions is the Nernst Equation. This equation allows us to calculate the electric potential of a redox reaction in "non-standard" situations. There exist tables of how much voltage, or potential, a reaction is capable of producing or consuming. These tables, known as standard potential tables, are created by measuring potential at "standard" conditions, with a pressure of 1 bar (≅1 atm), a temperature of 298° K (or 25° C, or room temperature) and with a concentration of 1.0 M for each of the products. This standard potential, or E°, can be corrected by a factor that includes the actual temperature of the reaction, the number of moles of electrons being transferred, and the concentrations of the redox reactants and products. The equation is:
Perhaps the best way of understanding this equation is through an example. Suppose we have this reaction:
Fe(s) + Cd2+(aq) ------> Fe2+(aq) + Cd(s)
In this reaction iron (Fe) is being oxidized to iron(II) ion, while the cadmium ion (Cd2+) in aqueous solution is being reduced to cadmium solid. The question is: how does this reaction behave in "non-standard" conditions?
The first thing to answer is how does it behave in standard conditions? We need to look at the standard potential for each half-reaction, then combine them to get a net potential for the reaction. The two (2) half-reactions are:
Fe2+ (aq) + 2 e- ------> Fe (s), E° = -0.44 V
Cd2+ (aq) +2 e- ------> Cd (s), E° = -0.40 V
Notice that both half-reactions are shown as reductions -- the species gains electrons, and is changed to a new form. But in the complete reaction above, Fe is oxidized, so the half-reaction needs to be reversed. Quite simply, the potential for the half-reaction of iron is now 0.44 V. To get the potential for the entire reaction, we add up the two (2) half-reactions to get 0.04 V for the standard potential.
The question now is: what is the total potential (in volts) for a nonstandard reaction? Suppose again that we have the same reaction, except now we have 0.0100 M Fe2+ instead of the standard 1.0 M. We need to use the Nernst equation to help us calculate that value. If you go to the Redox Half-Reaction Calculator, you should notice that the reaction is selected and the appropriate values are entered into the boxes. Since we don't have any species "B" or "D", we have entered zero for their concentrations. The concentration of the solid Fe is 1.0 M (actually, concentrations of solids and solvents (liquids) don't enter into the Nernst equation, but we set them to 1.0 so that the mathematics works out). If you click on the "Evaluate" button, you should learn that the standard potential is -0.44 V, while the nonstandard potential is -0.5 V. If you scroll down on the calculator, you can enter 0.5 as the first half-reaction. We again change the sign since we're actually reversing the Fe reaction
Using the calculator again, we calculate the nonstandard potential of the Cd reaction. Suppose we now have a concentration of Cd2+ of 0.005 M, what is its potential? The calculator should return a standard potential of -0.4 V and a nonstandard potential of -0.47 V. Place this value in the box for the second half-reaction, then click on "Evaluate". You should learn that the net nonstandard potential is 0.03 V, slightly less than the value of the net standard potential. Since this value is less than the net standard potential of 0.04 V, there is less of a tendency for this reaction to transfer electrons from reactants to products. In other words, less iron will be oxidized and cadmium will be reduced than at standard conditions.
Test your use of the redox calculator by calculating the net standard potential for this reaction:
2 Ag+ (aq, 0.80 M) + Hg (l)------> 2 Ag (s) + Hg2+ (aq, 0.0010M)
Answer: 0.025 V. Since the value is positive, the reaction will work to form the products indicated. Negative values of the potential indicate that the reaction tends to stay as reactants and not form the products. The net standard potential for this reaction is 0.01 V -- since the nonstandard potential is higher, this reaction will form products than the standard reaction.
Free energy and the standard potential can also be related through the following equation:
Where:
ΔG = change in free energy
n = number of moles
If a reaction is spontaneous, it will have a positive Eo, and negative ΔG, and a large K value (where K is the equilibrium constant-this is discussed more in the kinetics section).
The energy released in any spontaneous redox reaction can be used to perform electrical work using an electrochemical cell (a device where electron transfer is forced to take an external pathway instead of going directly between the reactants. Think of the reaction between zinc and copper. Instead of placing a piece of zinc directly into a solution containing copper, we can form a cell where solid pieces of zinc and copper are placed in two different solutions such as sodium nitrate. The two solids are called electrodes. The anode is the electrode where oxidation occurs and mass is lost where as the cathode is the electrode where reduction occurs and mass is gained. The two electrodes are connected by a circuit and the two (2) solutions are connected by a "salt bridge" which allows ions to pass through. The anions are the negative ions and they move towards the anode. The cations are the positive ions and they move towards the cathode.
The following is a diagram of an electrochemical cell with zinc and copper acting as the electrodes.
An external electric current hooked up to an electrochemical cell will make the electrons go backwards. This process is called electrolysis. This is used, for example, to make something gold plated. You would put the copper in a solution with gold and add a current which causes the gold ions to bond to the copper and therefore coating the copper. The time, current, and electrons needed determine how much "coating" occurs. The key to solving electolysis problems is learning how to convert between the units. Useful information: 1 A=1 C/sec; 96,500 coulombs can produce one (1) mole of e-; the electrons needed is determined by the charge of the ion involved
Example Problem: If you are trying to coat a strip with aluminum and you have a current of 10.0 A (amperes) running for one hour, what mass of Al is formed?
The solution of this problem involves a lengthly unit conversion process:
Redox reactions, or oxidation-reduction reactions, have a number of similarities to acid-base reactions. Fundamentally, redox reactions are a family of reactions that are concerned with the transfer of electrons between species. Like acid-base reactions, redox reactions are a matched set -- you don't have an oxidation reaction without a reduction reaction happening at the same time. Oxidation refers to the loss of electrons, while reduction refers to the gain of electrons. Each reaction by itself is called a "half-reaction", simply because we need two (2) half-reactions to form a whole reaction. In notating redox reactions, chemists typically write out the electrons explicitly:
Cu (s) ----> Cu2+ + 2 e-
This half-reaction says that we have solid copper (with no charge) being oxidized (losing electrons) to form a copper ion with a plus 2 charge. Notice that, like the stoichiometry notation, we have a "balance" between both sides of the reaction. We have one (1) copper atom on both sides, and the charges balance as well. The symbol "e-" represents a free electron with a negative charge that can now go out and reduce some other species, such as in the half-reaction:
2 Ag+ (aq) + 2 e- ------> 2 Ag (s)
Here, two silver ions (silver with a positive charge) are being reduced through the addition of two (2) electrons to form solid silver. The abbreviations "aq" and "s" mean aqueous and solid, respectively. We can now combine the two (2) half-reactions to form a redox equation:
We can also discuss the individual components of these reactions as follows. If a chemical causes another substance to be oxidized, we call it the oxidizing agent. In the equation above, Ag+ is the oxidizing agent, because it causes Cu(s) to lose electrons. Oxidants get reduced in the process by a reducing agent. Cu(s) is, naturally, the reducing agent in this case, as it causes Ag+ to gain electrons.
As a summary, here are the steps to follow to balance a redox equation in acidic medium (add the starred step in a basic medium):
1. Divide the equation into an oxidation half-reaction and a reduction half-reaction
2. Balance these
* Balance the elements other than H and O
* Balance the O by adding H2O
* Balance the H by adding H+
* Balance the charge by adding e-
3. Multiply each half-reaction by an integer such that the number of e- lost in one equals the number gained in the other
4. Combine the half-reactions and cancel
5. **Add OH- to each side until all H+ is gone and then cancel again**
In considering redox reactions, you must have some sense of the oxidation number (ON) of the compound. The oxidation number is defined as the effective charge on an atom in a compound, calculated according to a prescribed set of rules. An increase in oxidation number corresponds to oxidation, and a decrease to reduction. The oxidation number of a compound has some analogy to the pH and pK measurements found in acids and bases -- the oxidation number suggests the strength or tendency of the compound to be oxidized or reduced, to serve as an oxidizing agent or reducing agent. The rules are shown below. Go through them in the order given until you have an oxidation number assigned.
1. For atoms in their elemental form, the oxidation number is 0
2. For ions, the oxidation number is equal to their charge
3. For single hydrogen, the number is usually +1 but in some cases it is -1
4. For oxygen, the number is usually -2
5. The sum of the oxidation number (ONs) of all the atoms in the molecule or ion is equal to its total charge.
As a side note, the term "oxidation", with its obvious root from the word "oxygen", assumes that oxygen has an oxidation number of -2. Using this as a benchmark, oxidation numbers were assigned to all other elements. For example, if we look at H2O, and assign the value of -2 to the oxygen atom, the hydrogens must each have an oxidation number of +1 by default, since water is a neutral molecule. As an example, what is the oxidation number of sulfur in sulfur dioxide (SO2)? Given that each oxygen atom has a -2 charge, and knowing that the molecule is neutral, the oxidation number for sulfur must be +4. What about for a sulfate ion (SO4 with a total charge of -2)? Again, the charge of all the oxygen atoms is 4 x -2 = -8. Sulfur must then have an oxidation number of +6, since +6 + (-8) = -2, the total charge on the ion. Since the sulfur in sulfate has a higher oxidation number than in sulfur dioxide, it is said to be more highly oxidized.
Working with redox reactions is fundamentally a bookkeeping issue. You need to be able to account for all of the electrons as they transfer from one species to another. There are a number of rules and tricks for balancing redox reactions, but basically they all boil down to dealing with each of the two half-reactions individually. Consider for example the reaction of aluminum metal to form alumina (Al2O3). The unbalanced reaction is as follows:
Looking at each half reaction separately:
This reaction shows aluminum metal being oxidized to form an aluminum ion with a +3 charge. The half-reaction below shows oxygen being reduced to form two (2) oxygen ions, each with a charge of -2.
If we combine those two (2) half-reactions, we must make the number of electrons equal on both sides. The number 12 is a common multiple of three (3) and four (4), so we multiply the aluminum reaction by four (4) and the oxygen reaction by three (3) to get 12 electrons on both sides. Now, simply combine the reactions. Notice that we have 12 electrons on both sides, which cancel out. The final step is to combine the aluminum and oxygen ions on the right side using a cross multiply technique:
Taking care of the number of atoms, you should end up with:
One of the more useful calculations in redox reactions is the Nernst Equation. This equation allows us to calculate the electric potential of a redox reaction in "non-standard" situations. There exist tables of how much voltage, or potential, a reaction is capable of producing or consuming. These tables, known as standard potential tables, are created by measuring potential at "standard" conditions, with a pressure of 1 bar (≅1 atm), a temperature of 298° K (or 25° C, or room temperature) and with a concentration of 1.0 M for each of the products. This standard potential, or E°, can be corrected by a factor that includes the actual temperature of the reaction, the number of moles of electrons being transferred, and the concentrations of the redox reactants and products. The equation is:
Perhaps the best way of understanding this equation is through an example. Suppose we have this reaction:
Fe(s) + Cd2+(aq) ------> Fe2+(aq) + Cd(s)
In this reaction iron (Fe) is being oxidized to iron(II) ion, while the cadmium ion (Cd2+) in aqueous solution is being reduced to cadmium solid. The question is: how does this reaction behave in "non-standard" conditions?
The first thing to answer is how does it behave in standard conditions? We need to look at the standard potential for each half-reaction, then combine them to get a net potential for the reaction. The two (2) half-reactions are:
Fe2+ (aq) + 2 e- ------> Fe (s), E° = -0.44 V
Cd2+ (aq) +2 e- ------> Cd (s), E° = -0.40 V
Notice that both half-reactions are shown as reductions -- the species gains electrons, and is changed to a new form. But in the complete reaction above, Fe is oxidized, so the half-reaction needs to be reversed. Quite simply, the potential for the half-reaction of iron is now 0.44 V. To get the potential for the entire reaction, we add up the two (2) half-reactions to get 0.04 V for the standard potential.
The question now is: what is the total potential (in volts) for a nonstandard reaction? Suppose again that we have the same reaction, except now we have 0.0100 M Fe2+ instead of the standard 1.0 M. We need to use the Nernst equation to help us calculate that value. If you go to the Redox Half-Reaction Calculator, you should notice that the reaction is selected and the appropriate values are entered into the boxes. Since we don't have any species "B" or "D", we have entered zero for their concentrations. The concentration of the solid Fe is 1.0 M (actually, concentrations of solids and solvents (liquids) don't enter into the Nernst equation, but we set them to 1.0 so that the mathematics works out). If you click on the "Evaluate" button, you should learn that the standard potential is -0.44 V, while the nonstandard potential is -0.5 V. If you scroll down on the calculator, you can enter 0.5 as the first half-reaction. We again change the sign since we're actually reversing the Fe reaction
Using the calculator again, we calculate the nonstandard potential of the Cd reaction. Suppose we now have a concentration of Cd2+ of 0.005 M, what is its potential? The calculator should return a standard potential of -0.4 V and a nonstandard potential of -0.47 V. Place this value in the box for the second half-reaction, then click on "Evaluate". You should learn that the net nonstandard potential is 0.03 V, slightly less than the value of the net standard potential. Since this value is less than the net standard potential of 0.04 V, there is less of a tendency for this reaction to transfer electrons from reactants to products. In other words, less iron will be oxidized and cadmium will be reduced than at standard conditions.
Test your use of the redox calculator by calculating the net standard potential for this reaction:
2 Ag+ (aq, 0.80 M) + Hg (l)------> 2 Ag (s) + Hg2+ (aq, 0.0010M)
Answer: 0.025 V. Since the value is positive, the reaction will work to form the products indicated. Negative values of the potential indicate that the reaction tends to stay as reactants and not form the products. The net standard potential for this reaction is 0.01 V -- since the nonstandard potential is higher, this reaction will form products than the standard reaction.
Free energy and the standard potential can also be related through the following equation:
Where:
ΔG = change in free energy
n = number of moles
If a reaction is spontaneous, it will have a positive Eo, and negative ΔG, and a large K value (where K is the equilibrium constant-this is discussed more in the kinetics section).
The energy released in any spontaneous redox reaction can be used to perform electrical work using an electrochemical cell (a device where electron transfer is forced to take an external pathway instead of going directly between the reactants. Think of the reaction between zinc and copper. Instead of placing a piece of zinc directly into a solution containing copper, we can form a cell where solid pieces of zinc and copper are placed in two different solutions such as sodium nitrate. The two solids are called electrodes. The anode is the electrode where oxidation occurs and mass is lost where as the cathode is the electrode where reduction occurs and mass is gained. The two electrodes are connected by a circuit and the two (2) solutions are connected by a "salt bridge" which allows ions to pass through. The anions are the negative ions and they move towards the anode. The cations are the positive ions and they move towards the cathode.
The following is a diagram of an electrochemical cell with zinc and copper acting as the electrodes.
An external electric current hooked up to an electrochemical cell will make the electrons go backwards. This process is called electrolysis. This is used, for example, to make something gold plated. You would put the copper in a solution with gold and add a current which causes the gold ions to bond to the copper and therefore coating the copper. The time, current, and electrons needed determine how much "coating" occurs. The key to solving electolysis problems is learning how to convert between the units. Useful information: 1 A=1 C/sec; 96,500 coulombs can produce one (1) mole of e-; the electrons needed is determined by the charge of the ion involved
Example Problem: If you are trying to coat a strip with aluminum and you have a current of 10.0 A (amperes) running for one hour, what mass of Al is formed?
The solution of this problem involves a lengthly unit conversion process:
Jumat, 01 Januari 2010
Happy New Year 2010
Menjalani hari pertama di tahun 2010 ini, membuat ku mengingat semua kejadian dan peristiwa di tahun sebelumnya, yaitu tahun 2009..
Banyak hal yang udah aku alami, mulai dari pertemuan, perpisahan, kehilangan, cobaan, penyakit dan banyak hal lainnya.
Aku sebenarnya gak tahu, apakah aku dapat disebut sebagai orang yang mampu menghadapi tahun itu, ataukah hanya sekedar lepas dari kata tahun 2009.
Hal yang paling mengingatkanku adalah kehilangan 4orang sekaligus sahabat terdekat ku,
jujur aku gak sanggup ya ALLAH..
Bahkan di penghujung tahun 2009 pun bertambah lagi menjadi 5.
"satu satu , daun2 berguguran tingkalkan tangkainy,
satu-satu, burung kecil, berterbangan tingkalkan dahanny,
jauh2, tinggi..
Ke langit yang biru,"
mungkin lagu itulah yang paz buat aku.
Mungkin tema untuk tahun 2009 adalah kehilangan.
Kehilangan orang orang berharga,
aku gak bisa, aku gak bisa menemukan sosok mereka di kehipun ku sekarang,
Beside of that, orang tuaku juga mengalami pergantian sakit, dan aku betul2 gak tega,
aku ingin menggantikan sakit yang mereka alami,
cobaan demi cobaan dah dapat dilalui,
Aku pun berharap di tahun ini semua harapan menuju kebaikan dapat terwujud tahap demi tahap,
amin,
Banyak hal yang udah aku alami, mulai dari pertemuan, perpisahan, kehilangan, cobaan, penyakit dan banyak hal lainnya.
Aku sebenarnya gak tahu, apakah aku dapat disebut sebagai orang yang mampu menghadapi tahun itu, ataukah hanya sekedar lepas dari kata tahun 2009.
Hal yang paling mengingatkanku adalah kehilangan 4orang sekaligus sahabat terdekat ku,
jujur aku gak sanggup ya ALLAH..
Bahkan di penghujung tahun 2009 pun bertambah lagi menjadi 5.
"satu satu , daun2 berguguran tingkalkan tangkainy,
satu-satu, burung kecil, berterbangan tingkalkan dahanny,
jauh2, tinggi..
Ke langit yang biru,"
mungkin lagu itulah yang paz buat aku.
Mungkin tema untuk tahun 2009 adalah kehilangan.
Kehilangan orang orang berharga,
aku gak bisa, aku gak bisa menemukan sosok mereka di kehipun ku sekarang,
Beside of that, orang tuaku juga mengalami pergantian sakit, dan aku betul2 gak tega,
aku ingin menggantikan sakit yang mereka alami,
cobaan demi cobaan dah dapat dilalui,
Aku pun berharap di tahun ini semua harapan menuju kebaikan dapat terwujud tahap demi tahap,
amin,
Langganan:
Postingan (Atom)