Manganese

Today I´m going to talk about manganese

 

Manganese metal is gray-white, resembling iron, but is harder and very brittle. The metal is reactive chemically, and decomposes cold water slowly. Manganese is widely distributed throughout the animal kingdom. It is an important trace element and may be essential for utilisation of vitamin B. Manganese is present in quantity the floor of oceans. It is an important component of steel.

Table: basic information about and classifications of manganese.

Name: Manganese Symbol: Mn Atomic number: 25 Atomic weight: 54.938045 (5) Standard state: solid at 298 K CAS Registry ID: 7439-96-5

Group in periodic table: 7 Group name: (none) Period in periodic table: 4 Block in periodic table: d-block Colour: silvery metallic Classification: Metallic

Manganese: historical information

Manganese was discovered by Johann Gahn at 1774 in Sweden. Origin of name: from the Latin word "magnes" meaning "magnet", or "magnesia nigri" meaning "black magnesia" (MnO₂).

                             

 

 

 

Manganese metal was isolated by Gahn in 1774. He reduced the dioxide (MnO₂, as the mineral pyrolusite) with charcoal (essentially carbon) by heating and the result was a sample of the metal manganese.

Manganese: physical properties

• Melting point: 1519 [or 1246 °C (2275 °F)] K
• Boiling poin: 2334 [or 2061 °C (3742 °F)] K
• Density of solid: 7470 kg m^-3

 

Manganese: orbital properties

• Ground state electron configuration:  [Ar].3d⁵.4s²
• Shell structure:  2.8.13.2
• Term symbol:   ⁶S_5/2
• Pauling electronegativity: 1.55 (Pauling units)
•  First ionisation energy: 717.3 kJ mol^-1
•  Second ionisation energy: 1509.0 kJ mol^-1

 

Isolation

Isolation: it is not normally necessary to make manganese in the laboratory as it is available commercially. Nearly all manganese produced commercially is used in the steel industry as ferromanganese. This made by the reduction of iron oxide, Fe₂O₃, and managanese dioxide, MnO₂, in appropriate proportions with carbon (as coke) in a blast furnace. Pure manganese is available through the electrolysis of manganese sulphate, MnSO₄,

Lead

Today I´m going to talk about lead

Lead is a bluish-white lustrous metal. It is very soft, highly malleable, ductile, and a relatively poor conductor of electricity. It is very resistant to corrosion but tarnishes upon exposure to air. Lead pipes bearing the insignia of Roman emperors, used as drains from the baths, are still in service. Alloys include pewter and solder. Tetraethyl lead (PbEt₄) is still used in some grades of petrol (gasoline) but is being phased out on environmental grounds.

Lead isotopes are the end products of each of the three series of naturally occurring radioactive elements.

Table: basic information about and classifications of lead.

Name: Lead Symbol: Pb Atomic number: 82 Atomic weight: 207.2 (1) Standard state: solid at 298 K CAS Registry ID: 7439-92-1

Group in periodic table: 14 Group name: (none) Period in periodic table: 6 Block in periodic table: p-block Colour: bluish white Classification: Metallic

Lead: historical information

Lead was discovered by Known since ancient times at no data in not known. Origin of name: from the Anglo-Saxon word "lead; Latin, plumbum" (the origin of the symbol Pb is the Latin word "plumbum" meaning "liquid silver".

                                  

 







Lead has been known for ages and is mentioned in Exodus. Alchemists believed lead to be the oldest metal and associated it with the planet Saturn. They spent a lot of time trying to "transmute" lead into gold.

Lead is one of the elements which has an alchemical symbol, shown below (alchemy is an ancient pursuit concerned with, for instance, the transformation of other metals into gold).

Sometime prior to the autumn of 1803, the Englishman John Dalton was able to explain the results of some of his studies by assuming that matter is composed of atoms and that all samples of any given compound consist of the same combination of these atoms. Dalton also noted that in series of compounds, the ratios of the masses of the second element that combine with a given weight of the first element can be reduced to small whole numbers (the law of multiple proportions). This was further evidence for atoms. Dalton's theory of atoms was published by Thomas Thomson in the 3rd edition of his System of Chemistry in 1807 and in a paper about strontium oxalates published in the Philosophical Transactions. Dalton published these ideas himself in the following year in the New System of Chemical Philosophy. The symbol used by Dalton for lead is shown below. [See History of Chemistry, Sir Edward Thorpe, volume 1, Watts & Co, London, 1914.]

 

Lead: physical properties

• Melting point: 600.61 [or 327.46 °C (621.43 °F)] K
• Boiling point: 2022 [or 1749 °C (3180 °F)] K
• Density of solid: 11340 kg m^-3

 

Lead: orbital properties

• Ground state electron configuration:  [Xe].4f¹⁴.5d¹⁰.6s².6p²
• Shell structure:  2.8.18.32.18.4
• Term symbol:   ³P₀
• Pauling electronegativity: 2.33 (Pauling units)
•  First ionisation energy: 715.6 kJ mol^-1
•  Second ionisation energy:  1450.5 kJ mol^-1

 

Isolation

Isolation: there is usually little need to make lead metal in the laboratory as it is so cheap and readily available. Lead is isolated from the sulphide, PbS. The process involves burning in a restricted air flow followed by reduction of the resulting oxide PbO with carbon.

PbS + ³/₂O₂ → PbO + SO₂

PbO + C → Pb + CO

PbO + CO → Pb + CO₂

This gives lead usually contaminated with metals such as antimony, arsenic, copper, gold, silver, tin, and zinc. A fairly complex process is used to strip out these impurities.

Platinum

Today I´m going to talk about platinum

Ruthenium, rhodium, palladium, osmium, iridium, and platinum together make up a group of elements referred to as the platinum group metals (PGM).

Platinum is a beautiful silvery-white metal, when pure, and is malleable and ductile. It has a coefficient of expansion almost equal to that of soda-lime-silica glass, and is therefore used to make sealed electrodes in glass systems.
The metal does not oxidise in air. It is insoluble in hydrochloric and nitric acid, but dissolves when they are mixed as aqua regia, forming chloroplatinic acid (H₂PtCl₆), an important compound. It is corroded by halogens, cyanides, sulphur and alkalis. Hydrogen and oxygen gas mixtures explode in the presence of platinum wire.

Table: basic information about and classifications of platinum.

Name: Platinum Symbol: Pt Atomic number: 78 Atomic weight: 195.084 (9) Standard state: solid at 298 K CAS Registry ID: 7440-06-4

Group in periodic table: 10 Group name: Precious metal or platinum group metal Period in periodic table: 6 Block in periodic table: d-block Colour: greyish white Classification: Metallic

Platinum: historical information

Platinum was discovered by Antonio de Ulloa at 1735 in South America. Origin of name: from the Spanish word "platina" meaning "silver".    
         

               

                                      

                     

                                                                 

The metal was used by pre-Columbian Indians but platinum was "rediscovered" in South America by Ulloa in 1735 and by Wood in 1741. In 1822 plenty of platinum was discovered in the Ural Mountains in Russia.

Platinum is one of the elements which has an alchemical symbol, shown below
Sometime prior to the autumn of 1803, the Englishman John Dalton was able to explain the results of some of his studies by assuming that matter is composed of atoms and that all samples of any given compound consist of the same combination of these atoms. Dalton also noted that in series of compounds, the ratios of the masses of the second element that combine with a given weight of the first element can be reduced to small whole numbers (the law of multiple proportions). This was further evidence for atoms. Dalton's theory of atoms was published by Thomas Thomson in the 3rd edition of his System of Chemistry in 1807 and in a paper about strontium oxalates published in the Philosophical Transactions. Dalton published these ideas himself in the following year in the New System of Chemical Philosophy. The symbol used by Dalton for platinum is shown below. [See History of Chemistry, Sir Edward Thorpe, volume 1, Watts & Co, London, 1914.]

 

Platinum: physical properties

• Melting point: 2041.4 [or 1768.3 °C (3214.9 °F)] K
• Boiling point: 4098 [or 3825 °C (6917 °F)] K
• Density of solid: 21090 kg m^-3

 

Platinum: orbital properties

• Ground state electron configuration:  [Xe].4f¹⁴.5d⁹.6s¹
• Shell structure:  2.8.18.32.17.1
• Term symbol:   ³D₃
• Pauling electronegativity: 2.28 (Pauling units)
•  First ionisation energy: 870 kJ mol^-1
•  Second ionisation energy: 1791 kJ mol^-1

 

Isolation

Isolation: it would not normally be necessary to make a sample of platinum in the laboratory as the metal is available commercially. The industrial extraction of platinum is complex as the metal occurs in ores mixed with other metals such as palladium and gold. Sometimes extraction of the precious metals such as platinum and palladium is the main focus of a partiular industrial operation while in other cases it is a byproduct. The extraction is complex and only worthwhile since platinum is the basis of important catalysts in industry.

Preliminary treatment of the ore or base metal byproduct with aqua regia (a mixture of hydrochloric acid, HCl, and nitric acid, HNO₃) gives a solution containing complexes of gold and palladium as well as H₂PtCl₆. The gold is removed from this solution as a precipitate by treatment with iron chloride (FeCl₂). The platinum is precipitated out as impure (NH₄)₂PtCl₆ on treatment with NH₄Cl, leaving H₂PdCl₄ in solution. The (NH₄)₂PtCl₆ is burned to leave an impure platinum sponge. This can be purified by redissolving in aqua regia, removal of rhodium and iridium impurities by treatment of the solution with sdoium bromate, and precipitation of pure (NH₄)₂PtCl₆ by treatment with ammonium hydroxide, NH₄OH. This yields platinum metal by burning.

Zinc

Today I´m going to talk about zinc

Zinc-deficient animals require 50% more food to gain the same weight of an animal supplied with adequate amounts of zinc. Zinc is not particularly toxic and is an essential element in the growth of all animals and plants.

Plating thin layers of zinc on to iron or steel is known as galvanising and helps to protect the iron from corrosion.

Table: basic information about and classifications of zinc.

Name: Zinc Symbol: Zn Atomic number: 30 Atomic weight: 65.38 (2) Standard state: solid at 298 K CAS Registry ID: 7440-66-6

Group in periodic table: 12 Group name: (none) Period in periodic table: 4 Block in periodic table: d-block Colour: bluish pale grey Classification: Metallic

Zinc: historical information

Zinc was discovered by Andreas Marggraf at 1746 in Germany. Origin of name: from the German word "zink".

 

 

 

 

 

 

 

Centuries before zinc was recognized as a distinct element, zinc ores were used for making brass (a mixture of copper and zinc). A brass dating from between 1400-1000 BC has been found in Palestine. An alloy containing 87% zinc was found in prehistoric ruins in Transylvania. The smelting of zinc ores with copper was apparently discovered in Cyprus and was used later by the Romans. Metallic zinc was produced in the 13th century in India by reducing calamine (zinc carbonate, ZnCO₃) with organic substances such as wool.

The metal was rediscovered later in Europe. William Champion set up a zinc industry in Bristol (England) in the 1740s. Other plants were established a little later in Belgium and Silesia.
Sometime prior to the autumn of 1803, the Englishman John Dalton was able to explain the results of some of his studies by assuming that matter is composed of atoms and that all samples of any given compound consist of the same combination of these atoms. Dalton also noted that in series of compounds, the ratios of the masses of the second element that combine with a given weight of the first element can be reduced to small whole numbers (the law of multiple proportions). This was further evidence for atoms. Dalton's theory of atoms was published by Thomas Thomson in the 3rd edition of his System of Chemistry in 1807 and in a paper about strontium oxalates published in the Philosophical Transactions. Dalton published these ideas himself in the following year in the New System of Chemical Philosophy. The symbol used by Dalton for zinc is shown below. [See History of Chemistry, Sir Edward Thorpe, volume 1, Watts & Co, London, 1914.]

 

Zinc: physical properties

• Melting point: 692.68 [or 419.53 °C (787.15 °F)] K
• Boiling point: 1180 [or 907 °C (1665 °F)] K
• Density of solid: 7140 kg m^-3

 

Zinc: orbital properties

• Ground state electron configuration:  [Ar].3d¹⁰.4s²
• Shell structure:  2.8.18.2
• Term symbol:   ¹S₀
• Pauling electronegativity: 1.65 (Pauling units)
•  First ionisation energy: 906.4 kJ mol^-1
•  Second ionisation energy: 1733.3 kJ mol^-1

 

Isolation

Isolation: zinc metal is readily available commercially so it is not normally necesary to make it in the laboratory. Most zinc production is based upon sulphide ores. These are roasted in industrial plants to form zinc oxide, ZnO. This may be reduced with carbon to form zinc metal, but in practice ingenious technology is required to ensure that the resulting zinc does not contain oxide impurities.

ZnO + C → Zn + CO

ZnO + CO → Zn + CO₂

CO₂ + C → 2CO

The other type of extraction is electrolytic. Dissolution of crude zinc oxide, ZnO, in sulphuric acid gives zinc sulphate, ZnSO₄ in solution. Cadmium is an impurity and this is removed as a precipitate of cadmium sulphate by the addition of zinc dust. Electrolysis of the ZnSO₄ solution using aluminium cathodes and lead alloyed with silver anodes gives pure zinc metal coated on the aluminium. Oxygen gas is liberated at the anode.
Very pure zinc may be formed from crude zinc by zone refining and single crystals can be grown with purities of better than 99.9999%.

Aluminium

Today I´m going to talk about aluminium

Pure aluminium is a silvery-white metal with many desirable characteristics. It is light, nontoxic (as the metal), nonmagnetic and nonsparking. It is somewhat decorative. It is easily formed, machined, and cast. Pure aluminium is soft and lacks strength, but alloys with small amounts of copper, magnesium, silicon, manganese, and other elements have very useful properties. Aluminium is an abundant element in the earth's crust, but it is not found free in nature. The Bayer process is used to refine aluminium from bauxite, an aluminium ore.

Table: basic information about and classifications of aluminium.

Name: Aluminium Symbol: Al Atomic number: 13 Atomic weight: 26.9815386 (8) Standard state: solid at 298 K CAS Registry ID: 7429-90-5

Group in periodic table: 13 Group name: (none) Period in periodic table: 3 Block in periodic table: p-block Colour: silvery Classification: Metallic

 Small and large samples of aluminium foil, sheet, wire, rod and tube like this (and aluminium alloy in rod form) can be purchased via their web catalogue from Advent Research Materials via their web catalogue.

Aluminium: historical information

Aluminium was discovered by Hans Christian Oersted at 1825 in Denmark. Origin of name: from the Latin word "alumen" meaning "alum".

                                

 

 

 

 

 

 

The ancient Greeks and Romans used alum in medicine as an astringent, and in dyeing processes. In 1761 de Morveau proposed the name "alumine" for the base in alum. In 1807, Davy proposed the name alumium for the metal, undiscovered at that time, and later agreed to change it to aluminum. Shortly thereafter, the name aluminium was adopted by IUPAC to conform with the "ium" ending of most elements. Aluminium is the IUPAC spelling and therefore the international standard. Aluminium was also the accepted spelling in the U.S.A. until 1925, at which time the American Chemical Society decided to revert back to aluminum, and to this day Americans still refer to aluminium as "aluminum".

Aluminium is one of the elements which as alum or alumen, KAl(SO₄)₂, has an alchemical symbol
Aluminium was first isolated by Hans Christian Oersted in 1825 who reacted aluminium chloride (AlCl₃) with potassium amalgam (an alloy of potassium and mercury). Heating the resulting aluminium amalgam under reduced pressure caused the mercury to boil away leaving an impure sample of aluminium metal.

Aluminium: physical properties

• Melting point: 933.47 [or 660.32 °C (1220.58 °F)] K
• Boiling point: 2792 [or 2519 °C (4566 °F)] K
• Density of solid: 2700 kg m^-3

 

Aluminium: orbital properties

• Ground state electron configuration:  [Ne].3s².3p¹
• Shell structure:  2.8.3
• Term symbol:   ²P_1/2
• Pauling electronegativity: 1.61 (Pauling units)
•  First ionisation energy: 577.5 kJ mol^-1
•  Second ionisation energy: 1816.7 kJ mol^-1

 

Isolation

Isolation: aluminium would not mormally be made in the laboratory as it is so readily available commercially.

Aluminium is mined in huge scales as bauxite (typically Al₂O₃.2H₂O). Bauxite contains Fe₂O₃, SiO₂, and other impurities. In order to isolate pure aluminium, these impurities must be removed from the bauxite. This is done by the Bayer process. This involves treatment with sodium hydroxide (NaOH) solution, which results in a solution of sodium aluminate and sodium silicate. The iron remains behind as a solid. When CO₂ is blown through the resulting solution, the sodium silicate stays in solution while the aluminium is precipitated out as aluminium hydroxide. The hydroxide can be filtered off, washed, and heated to form pure alumina, Al₂O₃.
The next stage is formation of pure aluminium. This is obtained from the pure Al₂O₃ by an electrolytic method. Electrolysis is necessary as aluminium is so electropositive. It seems these days that electrolysis of the hot oxide in a carbon lined steel cell acting as the cathode with carbon anodes is most common.

Silver

Today I´m going to talk about silver

Silver is somewhat rare and expensive, although not as expensive as gold. Slag dumps in Asia Minor and on islands in the Aegean Sea indicate that man learned to separate silver from lead as early as 3000 B.C. Pure silver has a brilliant white metallic lustre. It is a little harder than gold and is very ductile and malleable. Pure silver has the highest electrical and thermal conductivity of all metals, and possesses the lowest contact resistance. Silver iodide, AgI, is (or was?) used for causing clouds to produce rain.

Silver is stable in pure air and water, but tarnishes when exposed to ozone, hydrogen sulphide, or air containing sulphur. It occurs in ores including argentite, lead, lead-zinc, copper and gold found in Mexico, Peru, and the USA.

The result of aqueous ignition of a mixture of magnesium metal with silver nitrate with water (only to be demonstrated by a professionally qualified chemist following a legally satisfactory hazard asessment). Improperly done, this reaction is dangerous!

 

Table: basic information about and classifications of silver.

Name: Silver Symbol: Ag Atomic number: 47 Atomic weight: 107.8682 (2) Standard state: solid at 298 K CAS Registry ID: 7440-22-4

Group in periodic table: 11 Group name: Coinage metal Period in periodic table: 5 Block in periodic table: d-block Colour: silver Classification: Metallic

Silver: historical information

Silver was discovered by Known since ancient times at no data in not known. Origin of name: from the Anglo-Saxon word "siolfur" meaning "silver" (the origin of the symbol Ag comes from the Latin word "argentum" meaning "silver").

                           

Silver has been known since ancient times. It is mentioned in Genesis. Slag dumps in Asia Minor and on islands in the Aegean Sea indicate that man learned to separate silver from lead as early as 3000 B.C.

Silver is one of the elements which has an alchemical symbol, shown below (alchemy is an ancient pursuit concerned with, for instance, the transformation of other metals into gold).


Sometime prior to the autumn of 1803, the Englishman John Dalton was able to explain the results of some of his studies by assuming that matter is composed of atoms and that all samples of any given compound consist of the same combination of these atoms. Dalton also noted that in series of compounds, the ratios of the masses of the second element that combine with a given weight of the first element can be reduced to small whole numbers (the law of multiple proportions). This was further evidence for atoms. Dalton's theory of atoms was published by Thomas Thomson in the 3rd edition of his System of Chemistry in 1807 and in a paper about strontium oxalates published in the Philosophical Transactions. Dalton published these ideas himself in the following year in the New System of Chemical Philosophy. The symbol used by Dalton for silver is shown below. [See History of Chemistry, Sir Edward Thorpe, volume 1, Watts & Co, London, 1914.]

Silver: physical properties

• Melting point: 1234.93 [or 961.78 °C (1763.2 °F)] K
• Boiling point:2435 [or 2162 °C (3924 °F)] K
• Density of solid: 10490 kg m^-3

 

Silver: orbital properties

• Ground state electron configuration:  [Kr].4d¹⁰.5s¹
• Shell structure:  2.8.18.18.1
• Term symbol:   ²S_1/2
• Pauling electronegativity: 1.93 (Pauling units)
•  First ionisation energy: 731.0 kJ mol^-1
•  Second ionisation energy: 2070 kJ mol^-1

 

Isolation

Isolation: silver is readily available commercially so it is not normally necessary to prepare silver in the laboratory. However the formation of silver metal may be demonstrated in a satisfying reaction in which copper metal is dipped into a solution of silver nitrate, AgNO₃.

Cu(s) + 2 AgNO₃ (aq) → Cu(NO₃)₂ + 2 Ag (s)

The result is formation of often attractive silver crystals and a blue-green solution of copper nitrate. Industrially, silver is usually a byproduct of processes whose main object is the extraction of another metal such as copper, lead, and zinc. So called "anode slimes" from the electrolytic purification of copper contain silver and a somewhat involved process is finished by an electrolysis of a nitrate solution containing silver.

Titanium

Today I´m going to talk about titanium

Titanium s a lustrous, white metal when pure. Titanium minerals are quite common. The metal has a low density, good strength, is easily fabricated, and has excellent corrosion resistance. The metal burns in air and is the only element that burns in nitrogen. It is marvellous in fireworks.

Titanium is resistant to dilute sulphuric and hydrochloric acid, most organic acids, damp chlorine gas, and chloride solutions. Titanium metal is considered to be physiologically inert.
Titanium is present in meteorites and in the sun. Some lunar rocks contain high concentrations of the dioxide, TiO₂. Titanium oxide bands are prominent in the spectra of M-type stars.

Table: basic information about and classifications of titanium.

Name: Titanium Symbol: Ti Atomic number: 22 Atomic weight: 47.867 (1) Standard state: solid at 298 K CAS Registry ID: 7440-32-6

Group in periodic table: 4 Group name: (none) Period in periodic table: 4 Block in periodic table: d-block Colour: silvery metallic Classification: Metallic

Titanium: historical information

Titanium was discovered by William Gregor at 1791 in England. Origin of name: named after the "Titans", (the sons of the Earth goddess in Greek mythology).

                                   

Titanium was discovered by the Reverend William Gregor in 1791, who was interested in minerals. He recognized the presence of a new element, now known as titanium, in menachanite, a mineral named after Menaccan in Cornwall (England). Several years later, the element was rediscovered in the ore rutile by a German chemist, Klaproth.

The pure elemental metal was not made until 1910 by Matthew A. Hunter, who heated TiCl₄ together with sodium in a steel bomb at 700-800°C.

Titanium: physical properties

• Melting point: 1941 [or 1668 °C (3034 °F)] K
• Boiling point: 3560 [or 3287 °C (5949 °F)] K
• Density of solid: 4507 kg m^-3

 

Titanium: orbital properties

• Ground state electron configuration:  [Ar].3d².4s²
• Shell structure:  2.8.10.2
• Term symbol:   ³F₂
• Pauling electronegativity: 1.54 (Pauling units)
•  First ionisation energy: 658.8 kJ mol^-1
•  Second ionisation energy: 1309.8 kJ mol^-1

 

Isolation

Isolation: titanium is readily available from commercial sources so preparation in the laboratory is not normally required. In industry, reduction of ores with carbon is not a useful option as intractable carbides are produced. The Kroll method is used on large scales and involves the action of chlorine and carbon upon ilmenite (TiFeO₃) or rutile (TiO₂). The resultant titanium tetrachloride, TiCl₄, is separated from the iron trichloride, FeCl₃, by fractional distillation. Finally TiCl₄ is reduced to metallic titanium by reduction with magnesium, Mg. Air is excluded so as to prevent contamination of the product with oxygen or nitrogen.

2TiFeO₃ + 7Cl₂ + 6C (900°C) → 2TiCl₄ + 2FeCl₃ + 6CO

TiCl₄ + 2Mg (1100°C) → 2MgCl₂ + Ti

Excess magensium and magneium dichloride is removed from the product by treatment with water and hydrochloric acid to leave a titanium "sponge". This can be melted under a helium or argon atmosphere to allow casting as bars.