Carbon has property of forming chains and bonds. It was believed that carbon compounds can be obtained from nature only until the discovery of urea by Friedrich Wöhler in 1828.
Urea or carbamide is an organic compound. Its chemical formula is CO(NH2)2.
Allotrope
Allotrope are compounds with same element structure but different chemical and physical properties.
Allotrope of carbon compounds
Allotropic nature of carbon compounds can be found in black coke, graphite, diamond and fullerene (Bucky ball). The carbon compounds can be bonded differently in these carbon allotrope.
Cabon name – a general concept
| Single Bond | Double Bond | Triple Bond | |
| CnH2n+2 | CnH2n | CnH2n-2 | |
| C1 | Methane (CH4) | Methene (C1H2) | |
| C2 | Ethane (C2H6) | Ethene (C2H4) | Ethyne (C2H2) |
| C3 | Propane (C3H8) | Propene (C3H6) | Propyne (C3H4) |
| C4 | Butane (C4H10) | Butene (C4H8) | Butyne (C4H6) |
| C5 | Pentane (C5H12) | Pentene (C5H10) | Pentyne (C5H8) |
| C6 | Hexane (C6H14) | Hexene (C6H12) | Hexyne (C6H10) |
| C7 | Septane (C7H16) | Septene (C7H14) | Septyne (C7H12) |
| C8 | Octane (C8H18) | Octene (C8H16) | Octyne (C8H14) |
| C9 | Nonane (C9H20) | Nonene (C9H18) | Nonyne (C9H16) |
| C10 | Decane (C10H22) | Decene (C10H20) | Decyne (C10H18) |
Carbon Functional group
| Aldehyde | CHO |
| Acid | COOH |
| Ketone | CO |
| Ester | O=CO |
| Amines | NH2 |
| Alcohol | OH |
Coal
Four types of coal exist in nature. They are
- Peat
- Bituminous
- Lignite
- Anthracite
Fuel
- Saturated hydrocarbons give blue flame while burning
- Unsaturated hydrocarbons give yellow flame
- Coal and petroleum have small quality of sulfur and nitrogen whose oxide create pollution
Saturated and unsaturated fats
Animals fat is saturated which is harmful. Vegetable oil has long chain of unsaturated carbon compounds which is healthy.
Esterification
Acetic acid reacts with ethyl alcohol to make sweet smelling esters. This process is called esterification.
C2H5OH + HOOCH3C -> C2H5COOCH3 + H2O
Polymer
Poly means many Macro molecules with same and repeated elements are called polymer. They can be obtained naturally or synthetically e.g. clothes of cotton or wool is natural polymer. Plastic and synthetic yarn is synthetic polymer.
Synthetic polymers like nylon are very strong that parachute is made out of it. Thermoplastic can be changed into different shapes on burning e.g. polythene and PVC(polyvinylchloride). Thermostatic plastic are those plastics which after it’s manufactured are resistant to heat. Melamine and Bakelite are more heat resistant than polythene Switches are made of melamine which is resistant to electricity.
n(C2H4) -> -[-CH2-CH2-]n–
Petroleum
World’s first petroleum well was drilled in Pennsylvania, America. Petroleum was made from buried dead animals in sea; hence it’s also called fossil fuel. The dead animals in sea remained under silt for millions of years. In absence of air and high temperature and pressure petroleum converted to gas.
It consists of various hydrocarbons like alkanes (paraffins), cycloalkanes(naphthenes) and aromatic hydrocarbons and other substances like nitrogen, oxygen, sulphur, etc. A hydrocarbon is a compound of hydrogen and carbon.
Alkanes are acyclic hydrocarbons having single bond between carbon and hydrogen. The general formula is CnH2n+2.
| Alkane | Use |
| Methane (CH4) to Butane(C4H10) | Gaseous state |
| Propane(C5H12) to Octane(C8H18) | Refined into gasoline |
| Nonane(C9H20) to Hexadecane(C16H34) | Refined into diesel, kerosene, jet fuel |
| Heptadecane(C17H36 ) to higher hydrocarbons | Lubricating oil, paraffin wax, asphalt(tar coal) |
Constitution of petroleum
Petrol, diesel, paraffin, lubricant, kerosene, bitumen, LPG.
Use
Petroleum or natural gas is called petrochemical. Detergent, synthetic fiber, polythene and plastic are obtained from petrochemical. Hydrogen obtained from natural gas is used for making urea.
Ethanol C2H5OH
Ethanol is a good solute. It is used in cough syrups, tincture iodine, tonics and medicines. Its melting point is 156 and boiling point 356K.
Displacement reaction
CH4+Cl2 –> CHCl3( chloroform)
- It is used in making thermometers and spirit label
- used for making ether chloroform
- used as antifreeze in radiator for effective car driving
- Preserves zoological species
Fuel and Ethanol
During processing of sugarcane juice, a dark coloured viscous liquid called molasses is produced. Molasses contains 55-60% sugar in the form of sucrose (C12H22O11). Molasses is fermented by adding water, ammonium sulphate and sulphuric acid. Nitrogen present in ammonium sulphate and suphuric acid helps in growth of yeast. The enzymes invertase and zymase present in the yeast converts the sugar (sucrose) present in molasses to ethanol. The enzyme invertase helps in breaking sucrose to glucose and fructose.
C12H22O11 + H2O + invertase → C6H12O6 + C6H12O6
sucrose + water + invertase → glucose + fructose
The enzyme zymase converts glucose to ethanol and carbon dioxide.
C6H12O6 + zymase→ 2C2H5OH + 2CO2
Glucose → Ethanol + Carbon dioxide
Ethanol mixed with petroleum is used as fuel in some countries. Ethanol in presence of oxygen gives CO2 and water.
C2H5OH + 3O2 → 2CO2 + 3H2O
Ethanol + Oxygen → Carbon dioxide + Water
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