Chemistry of Carbon Chemistry of Carbon CompoundsCompounds

Properties of CarbonProperties of CarbonAllotropesAllotropesInorganic Compounds of CarbonInorganic Compounds of CarbonOrganic ChemistryOrganic Chemistry

CARBONCARBON

non-metallic element of group IV-A which non-metallic element of group IV-A which constitutes only about 0.009 % by mass of constitutes only about 0.009 % by mass of Earth’s crust. (but it is the 6Earth’s crust. (but it is the 6 thth most abundant most abundant element in the universe)element in the universe)

exists in three isotopes: exists in three isotopes: 1212C, C, 1313C, C, 1414CC has the unique ability to form long chains has the unique ability to form long chains

(consisting of more than 50 C atoms) and (consisting of more than 50 C atoms) and stable five or six-membered rings called stable five or six-membered rings called catenation.catenation.   

Some Physical Properties of Some Physical Properties of CarbonCarbon

Atomic number: Atomic number: 66 Electron Configuration:Electron Configuration: 1s1s222s2s222p2p22

Atomic mass: Atomic mass: 12.0107 amu12.0107 amu Melting Point: Melting Point: 3,823 K3,823 K Boiling Point: Boiling Point: 4,098 K4,098 K Density: Density: 2.2670 g/cm2.2670 g/cm33

Phase (room temp.): Phase (room temp.): solidsolid

AllotropesAllotropes

two or more forms of the same element two or more forms of the same element that differ significantly in chemical & that differ significantly in chemical & physical properties.physical properties.

Allotropes of Carbon

Crystall ine-Crystall ine- have highly ordered 3D structure have highly ordered 3D structure1.1. graphitegraphite2.2. diamonddiamond3.3. fullerenesfullerenes

AmorphousAmorphous1.1. carbon blackcarbon black2.2. charcoalcharcoal3.3. cokecoke

GraphiteGraphite

        graphite is derived from the Greek word graphite is derived from the Greek word “graphein” which means “graphein” which means to writeto write. It was . It was named by the German Geologist named by the German Geologist Abraham Werner in 1789. Abraham Werner in 1789.

Properties & Uses of Graphite

soft, greasy feel black mineralsoft, greasy feel black mineral is made up of layers of carbon, the Carbon atoms is made up of layers of carbon, the Carbon atoms

arranged in rings of 6 atoms.arranged in rings of 6 atoms. layers slide easily over each other because of the layers slide easily over each other because of the

weak inter-layer forces (Van der Waal’s forces) but weak inter-layer forces (Van der Waal’s forces) but inter atomic bonds are strong covalent bondsinter atomic bonds are strong covalent bonds

contains free electrons, which move along layerscontains free electrons, which move along layers good conductor of heat & electricitygood conductor of heat & electricity used as pencil lead, lubricants, electrodes & raw used as pencil lead, lubricants, electrodes & raw

material for making synthetic diamondsmaterial for making synthetic diamonds

DiamondDiamond

transparent crystalline solid, with high density compared to other carbon allotropes

hardest naturally occurring substance carbon atom is joined to 4 other Carbon atoms,

forming a Tetrahedron, or 4 sided figure held together by covalent bonds

used as cutting material, jewelries & for decorative purposes

FullerenesFullerenes

a class of carbon molecules in which the a class of carbon molecules in which the carbon atoms are arranged into 12 pentagonal carbon atoms are arranged into 12 pentagonal faces and 2 or more hexagonal faces to form a faces and 2 or more hexagonal faces to form a hollow sphere, cylinder, or similar figure.hollow sphere, cylinder, or similar figure.

the most prominent of the fullerenes is the most prominent of the fullerenes is buckminsterfullerenebuckminsterfullerene , a spheroidal , a spheroidal molecule, resembling a soccer ball, consisting molecule, resembling a soccer ball, consisting of 60 carbon atoms. of 60 carbon atoms.

FullerenesFullerenes

fullerene research is expected to lead to new fullerene research is expected to lead to new materials, lubricants, coatings, catalysts, materials, lubricants, coatings, catalysts, electro-optical devices, and medical electro-optical devices, and medical applications.applications.

were first identified in 1985 by R. F. Curl, Jr., were first identified in 1985 by R. F. Curl, Jr., R. E. Smally, and H. W. Kroto (who shared the R. E. Smally, and H. W. Kroto (who shared the 1996 Nobel Prize in Chemistry) 1996 Nobel Prize in Chemistry)

STRUCTURE OF GRAPHITESTRUCTURE OF GRAPHITE

STRUCTURE OF DIAMONDSTRUCTURE OF DIAMOND

STRUCTURE OF STRUCTURE OF BUCKMINSTERFULLERENBUCKMINSTERFULLEREN

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Carbon BlackCarbon Black

formed when hydrocarbons such formed when hydrocarbons such as methane are heated in a very as methane are heated in a very limited supply of oxygen:limited supply of oxygen:

CHCH44 + O + O22 →→ C C (s)(s) + H + H22OO

used as pigment in black inks used as pigment in black inks and making automobile tiresand making automobile tires

CharcoalCharcoal

formed when wood is heated strongly in formed when wood is heated strongly in the absence of airthe absence of air

used in filters to remove offensive odors used in filters to remove offensive odors from air and colored or bad-tasting from air and colored or bad-tasting impurities form waterimpurities form water

CokeCoke

impure form of carbon formed when coal impure form of carbon formed when coal ((coalcoal - a fuel substance of plant origin, largely - a fuel substance of plant origin, largely or almost entirely composed of carbon with or almost entirely composed of carbon with varying amounts of mineral matter) is heated varying amounts of mineral matter) is heated strongly in the absence of air.strongly in the absence of air.

used as a reducing agent in metallurgical used as a reducing agent in metallurgical process.process.

Inorganic Compounds of Carbon

Oxides (carbon monoxide & carbon dioxide)

Carbonates Bicarbonates Carbides Cyanides

Carbon MonoxideCarbon Monoxide

a colorless, odorless, toxic gas formed a colorless, odorless, toxic gas formed by the incomplete combustion of carbon-by the incomplete combustion of carbon-containing compounds.containing compounds.

They are used for extracting nickels, They are used for extracting nickels, organic synthesis and production of organic synthesis and production of hydrocarbon fuels with hydrogenhydrocarbon fuels with hydrogen

Carbon DioxideCarbon Dioxide

a colorless, odorless, non-toxic gas.a colorless, odorless, non-toxic gas. it is an acidic oxide & used in beverages, it is an acidic oxide & used in beverages,

fire extinguishers, manufacture of baking fire extinguishers, manufacture of baking soda, NaHCOsoda, NaHCO33, and soda ash, Na, and soda ash, Na22COCO33..

COCO22 can also exist in solid form, called can also exist in solid form, called “dry ice”, which is used as a refrigerant.“dry ice”, which is used as a refrigerant.

CarbonatesCarbonates

are compounds containing the anion are compounds containing the anion COCO33

2-2-

examples are calcium carbonate which examples are calcium carbonate which can be found in egg shells, shells of can be found in egg shells, shells of marine organisms & in both limestone & marine organisms & in both limestone & marblemarble

CarbonatesCarbonates

Calcium carbonateCalcium carbonate is normally water- is normally water-insoluble. It will only dissolve in water insoluble. It will only dissolve in water saturated with COsaturated with CO22 because carbonated because carbonated water (or carbonic acid) reacts with water (or carbonic acid) reacts with calcium carbonate to form calcium calcium carbonate to form calcium bicarbonate, which is water-soluble:bicarbonate, which is water-soluble:

CaCOCaCO3(s)3(s) + H + H22COCO3(aq)3(aq) Ca Ca2+2+(aq)(aq) + 2HCO + 2HCO33

--(aq)(aq)

BicarbonatesBicarbonates

are compounds containing the anion HCOare compounds containing the anion HCO 33-- example is example is sodium bicarbonatesodium bicarbonate or baking or baking

soda NaHCOsoda NaHCO33, a weak base added to recipes , a weak base added to recipes to neutralize the acidity of other ingredients. to neutralize the acidity of other ingredients. Baking soda is a mixture of baking soda and Baking soda is a mixture of baking soda and a weak acid, like tartaric acid, that when a weak acid, like tartaric acid, that when mixed with water, the acid reacts with the mixed with water, the acid reacts with the HCOHCO33

- - ion to form COion to form CO22 gas, which causes the gas, which causes the dough or batter to rise.dough or batter to rise.HCOHCO33

--((aqaq)) H H++

((aqaq)) H H22COCO3(3(aqaq)) →→ H H22OO(( ll)) + CO + CO2(2(gg))

CarbidesCarbides

ionic compounds formed from the ionic compounds formed from the combination of carbon & metalscombination of carbon & metals

examples are CaCexamples are CaC22 (“carburo”) and (“carburo”) and BeBe22C in which carbon is in the form of C in which carbon is in the form of CC22

2-2- or C or C4-4- ions which are strong Bronsted ions which are strong Bronsted bases & reacts with water as:bases & reacts with water as:

CC222-2-

(aq)(aq) + 2H + 2H22OO(l)(l) →→ 2OH 2OH --(aq)(aq) + C + C22HH2(g)2(g)

CC4-4-(aq)(aq) + 4H + 4H22OO (l)(l) →→ 4OH 4OH --

(aq)(aq) + CH + CH4(g)4(g)

CarbidesCarbides

another example is the covalent another example is the covalent compound of carbon with silicon called compound of carbon with silicon called “carborundum” or silicon carbide, SiC.“carborundum” or silicon carbide, SiC.

it is almost as hard as diamond & it has it is almost as hard as diamond & it has the diamond structure which can be the diamond structure which can be prepared from the reaction:prepared from the reaction:

SiOSiO2(s)2(s) + 3C + 3C (s)(s) →→ SiC SiC(s)(s) + 2CO + 2CO (g)(g)

CyanidesCyanides

a carbon compound containing the anion a carbon compound containing the anion group :CNgroup :CN≡≡N:N:--

cyanide ions are extremely toxic cyanide ions are extremely toxic

used in the metallurgy of gold in the form used in the metallurgy of gold in the form of NaCNof NaCN