| Home » Chemistry Homework Help » Inorganic chemistry » Carbon |
Carbon
As charcoal and soot, carbon must have been known since very early times; the naturally occurring allotropes diamond and graphite were both known in ancient times also. These allotropes were shown to be pure carbon (by combustion to give carbon dioxide) at the end of the eighteenth century.
Occurrence
(1) Elemental: diamonds are found in South Africa, India, South America and Russia. The largest ever found was the Cullinan diamond which weighed about 600 g.
Graphite occurs naturally in Ceylon and other countries and was formerly mined in Cumberland. Its name (Greek grapho = 1 write) indicates its use in ‘lead’ pencils. Most graphite is now prepared artificially; natural graphite is often impure, and leaves an ash on burning. Coal contains some free carbon.
(2) Combined: carbon occurs as carbonates, many of which are minerals, e.g. limestone, marble CaCO3, and siderite, FeCO3; temporarily hard water contains calcium bicarbonate. Ca(HCO3)2. Carbon is present in the atmosphere as carbon dioxide can be extracted from the air by green plants and converted, with the aid of the complex pigment chlorophyll and in presence of sunlight (photosynthesis), to simple carbohydrates and finally to starch and cellulose. These products are then degraded, either directly or after being eaten by animals, into carbon dioxide by combustion with the oxygen of the air, thus completing the cycle. (Although the concentration of carbon dioxide in air is small, the volume of the atmosphere is so greater than in the entire animal and vegetable world.)
The products of the decay of primeval living matter occur as coal, petroleum (hydrocarbons) and asphalt, and all these contain flourished about three hundred million years ago; the decay was assisted by bacterial action, high temperatures and humidity. The decayed matter was finally compressed into a hard rocky state by the pressure of overlaying rock and earth which was thrown over the coal bed by the frequent disturbances of the earth’s crust. The geologically oldest coals are usually called anthracites; they contain over 90 percent of carbon together with hydrogen, nitrogen and oxygen (all combined in some form). Successively younger varieties are: ordinary coal (70-90 percent carbon), brown coal or lignite (60-70 percent of carbon) and lastly peat. The calorific value of these various coals (the amount of heat liberated by a given weight of coal) increases with age, anthracite yielding nearly twice the heat obtained from the same weight of peat.
Services:- Carbon Homework | Carbon Homework Help | Carbon Homework Help Services | Live Carbon Homework Help | Carbon Homework Tutors | Online Carbon Homework Help | Carbon Tutors | Online Carbon Tutors | Carbon Homework Services | Carbon
Occurrence
(1) Elemental: diamonds are found in South Africa, India, South America and Russia. The largest ever found was the Cullinan diamond which weighed about 600 g.
Graphite occurs naturally in Ceylon and other countries and was formerly mined in Cumberland. Its name (Greek grapho = 1 write) indicates its use in ‘lead’ pencils. Most graphite is now prepared artificially; natural graphite is often impure, and leaves an ash on burning. Coal contains some free carbon.
(2) Combined: carbon occurs as carbonates, many of which are minerals, e.g. limestone, marble CaCO3, and siderite, FeCO3; temporarily hard water contains calcium bicarbonate. Ca(HCO3)2. Carbon is present in the atmosphere as carbon dioxide can be extracted from the air by green plants and converted, with the aid of the complex pigment chlorophyll and in presence of sunlight (photosynthesis), to simple carbohydrates and finally to starch and cellulose. These products are then degraded, either directly or after being eaten by animals, into carbon dioxide by combustion with the oxygen of the air, thus completing the cycle. (Although the concentration of carbon dioxide in air is small, the volume of the atmosphere is so greater than in the entire animal and vegetable world.)
The products of the decay of primeval living matter occur as coal, petroleum (hydrocarbons) and asphalt, and all these contain flourished about three hundred million years ago; the decay was assisted by bacterial action, high temperatures and humidity. The decayed matter was finally compressed into a hard rocky state by the pressure of overlaying rock and earth which was thrown over the coal bed by the frequent disturbances of the earth’s crust. The geologically oldest coals are usually called anthracites; they contain over 90 percent of carbon together with hydrogen, nitrogen and oxygen (all combined in some form). Successively younger varieties are: ordinary coal (70-90 percent carbon), brown coal or lignite (60-70 percent of carbon) and lastly peat. The calorific value of these various coals (the amount of heat liberated by a given weight of coal) increases with age, anthracite yielding nearly twice the heat obtained from the same weight of peat.
Services:- Carbon Homework | Carbon Homework Help | Carbon Homework Help Services | Live Carbon Homework Help | Carbon Homework Tutors | Online Carbon Homework Help | Carbon Tutors | Online Carbon Tutors | Carbon Homework Services | Carbon
Submit Your Query ???
Assignment Help
Inorganic Chemistry
Organic Chemistsry
Analytical Chemistry
Biochemistry
Physical Chemistry
Topics
Aluminium
Aluminium Compounds
Aluminium Properties
Ammonia
Amorphous Preparation Properties
Antimony
Arsenic
Arsenic Compounds
Atomic Structure
Atomic Theory
Beryllium
Bismuth
Bisulphites And Sulphites
Boron
Boron Compounds
Calcium
Calcium Compounds
Carbon
Carbon Compounds
Chlorine
Covalent Bond Modern Theory
Deuterium
Diamond
Fluorine
Fuels
Graphite
Hydrogen Peroxide
Hydrogen Properties
Hydrogen Sulphide
Hydrogen-Discovery, Occurrence
Hydrogen-Industrial Preparation
Lead
Lead Compounds
Lithium, Rubidium, Caesium
Magnesium
Magnesium Compounds
Nitric Acid
Nitrogen
Nitrogen Dioxide
Oxides
Oxygen
Ozone
Phosphine
Phosphorus
Phosphorus Pentachloride
Potassium
Potassium Compounds
Silicon
Silicon Compounds
Sodium
Sodium Carbonate
Sodium Chloride
Sodium Hydride, Peroxide
Sodium Hydroxide
Sodium Hydroxide Properties
Sodium Properties
Strontium And Barium
Sulphides
Sulphur
Sulphur Dioxide
Sulphuric Acid
Tin
Tin Compounds
Valency Description
Valency Electronic Theory
Water
Water Purification
Water Softening Methods
Homework Help, Online Tutor, Online Tutoring Available For All Subjects. Some useful topics are given below :