LIST OF TOPICS
Here we will discuss about all important topics of carbon and its compounds class 10. Here you will get most important topics such as : IUPAC, Scum, Cleansing action of soap etc.
- INTRODUCTION OF CARBON
- ALLOTROPS OF CARBON
- USES OF ALLOTROPHS
- CHEMICAL PROPERTIES OF CARBON
- SOAP AND DETERGENT
- CLEANSING ACTION OF SOAP
- MICELLES AND SCUM
Carbon is a Non – metal element. It is involved in large number chemical compounds. These are present in plant and animals and also synthesised in the laboratory. These organic compounds have covalent bond. Earth’s crust has only 0.02% carbon in the form of minerals and atmosphere has 0.03% of carbon- di- oxide. There is large number of things which we use in our daily life that made up of carbon compounds. Such as: – Our food materials like grains, pulses, sugar, tea, coffee etc. The material like cotton, silk, wool, nylon and polyester which are used formatting clothes are carbon compounds. The fuels like wood, coal, kerosene, LPG, natural gas, CNG, petrol diesel which we use for the cooking food and running vehicles are carbon compound. Thus carbon considered as the essential element or say basic element for us.
- Carbon shows tetravalent character because its outermost shell (orbit) have 4, electron due to that it shows sharing thus from covalent bond. All members of 14thGroup have same characters.
- The property of self-combination of carbon atoms to form long chain is useful to us because it give large no. of organic comp.
- Carbon occurs in nature in free state as well as in combined state,. In free state- carbon occurs in nature in two forms diamond and Graphite. Another natural form is buckminsterfullerene.
In combined state- Carbon occurs in nature in the form of compound such as:- CO2, CaCO3, fossil fuels like coal, petroleum and natural gas, organic compound (Fat & proteins) & wood, cotton etc.
Allotropes of Carbon
It defined as the property of an element as a result of which it may exist in more than one form that are physically different but the chemically similar.
Diamond: It is the hardest crystalline form of carbon and is present in different parts of world as constituent of hard rock. It mainly found in Brazil, Africa etc. Diamond occurs as transparent octahedral crystals with curved surfaces. In structure of diamond each carbon atom is linked to four other carbon atoms by covalent bonds. Each c-c bond length is 154 pm. Becauseof high refractive index (2.42), it produces Maximum total internal reflection.
Use of diamond
- Due to hardness, diamond is used for cutting marble, granite & glass.
- It is used in making special S. knives.
- It is used as an abrasive and for polishing hard surfaces.
- Diamonds when properly cut and polished are used as precious stones or gems.
Graphite : It is another allotropic form of carbon. It occurs in Free State. It can be prepared artificially by heating a mix of sand and coke in electric furnace at about 3300 k. In structure of graphite, each carbon atom is linked to three other carbons by covalent bond and thus forms hexagonal rings that arranged and form layer of it. These layers held together by weak forces of attraction and b/w these layers 335 pm. Distance is presents.
Uses of Graphite
- It is used to make electrodes for electrolytic cells.
- Being soft and greasy, it is used as lubricant in parts of machines.
- Graphite is also used to moderate the speed of the fast moving neutron in nuclear reactors.
- Graphite is used to prepare china-dish because have high melting point.
- Graphite is used to make core of lead pencils.
Fullerenes: It is recently prepared allotropic form of carbon. These were formed by H.W. kroto, Smalley and Robert by action of laser beam on a sample of graphite in vapour state. It is the combination of 60 carbon atom.
Uses of Fullerenes
- Fullerenes in small amount can catalyse the photo chemical refining in Industry.
- Fullerenes help in improving antifriction properties of lubricating oils.
- In pure state fullerenes act as the insulator, but can be converted into semi- conductor.
Formation of Covalent Compound
Bond formed by the sharing of electrons in participating atoms called covalent bond, and formed compound is covalent compound. Formed compound may be of two types:- (A) Homoatomic& (B) Heteroatomic.Such as:
- Cl2 Molecule
- O2 Molecule
Carbon compound exist in large number due to two main properties of carbons:-
- Tetravalent character
- Catenation (self-linking property of an element due to which a large no. of atoms can be linked with each other by covalent bonds).
Causes of catenation
Carbon atom is tetravalent in nature which means it has four valence electrons, to complete its octate
- It combines with four other carbon atom by covalent bond, C—C bond dissociation energy is high ( 355KJ/mol) in comparison of other member of group.
Classification of Organic compound
- Open chain- In thin carbon atoms are linked to each other by the covalent bonds. Such as: – C6H14, C3H8.
- Closed chain or Cyclic Compounds.
- Alicyclic Compound: – The compounds containing one or more rings of three or more carbon atoms are called alicyclic compound. Such as – Cyclopentane (C5H10) etc.
Aromatic Compound: These are cyclic compounds which contain one or more hexagonal rings of carbon atoms with three double bonds in alternate positions. This is known as benzene ring, such as There also derivatives.
- Heterocyclic Compound. Both alicyclic and aromatic compounds have rings of carbon atoms only. These are therefore homocyclic in nature. In heterocyclic compound, ring may contain one or more atoms of either N, O or S etc such as;-
|NAME of F.G.||SYBOLS||SUFFIX||EXAMPLE|
Chemical Properties of Carbon Compound
- Combustion Reaction (oxidation)
It means heating a substance strongly in excess of oxygen or air, as a result it gets oxidised, such as:-
CH4 +2O2CO2 +2H2O + light
C6H6+ 15/2O2 6CO2 +3H2O + light
Blue flame indicates complete combustion of fuel. These flames are Non-sooty flame.
Yellow flame indicates incomplete combustion of fuel. These flames are sooty flame.
Coal and petroleum are the major source of fuels in spite of their pollution problem. Both have been formed from biomass which undergoes various biological changes.
- Coal resulted from the remains of trees and other plants which have been buried million yearsago. This may due to earth quakes &volcanic eruption. Thus due to high temperature their slow combustion into coal, which exists in coal, mines.
Petroleum has resulted from fossil fuels such as perishable marine creatures which died millions of year ago and sank to sea-bed. They were covered and surrounded by mud. High temperature, pressure & bacteria caused their decomposition into crude oil & natural gas. These moved upwards through the porous rocks but generally trapped inside layer of Non-porous rock. Thus reservoirs of oil and gas were created.
- Addition Reaction
In this type of reaction we added the Hydrogen to alkene or alkyne to from alkane in presence of catalyst. Such as:
HC= CH +2H2Ni CH3-CH3
H2C= CH2 + H2Ni CH3-CH3
Hydrogenation of oil: Vegetable oils (like ground nut oil, cotton seed oil and mustard oil) are unsaturated compounds containing double bonds. They are in the liquid state at room tem. This undergoes addition of Hydrogen just like alkenes to from saturated products called vegetable ghee.
- Substitution Reaction: These reactions are also called the replacement reaction. Such as:
CH4 + Cl2 CH3Cl + HCL
Soaps and Detergents
Soaps: Soaps are the sodium and potassium salts of long chain fatty acids with formula RCOONa Such as: Sodium stearate (C17 H35 Coo–Na+), Sodium palmitate (C15H31Coo–Na+).
- Soap is cheaper and readily available.
- It works well in soft water(which does not contain Ca2+and Mg2+).
- Soaps are 100% biodegradable.
They act like soap in having the cleansing properties, they do not contain the usual soaps like sodium stearates they have better cleansing action than soaps because they do not form insoluble calcium & Magnesium salts hard water and hence can be used for washing even with hard water.
- Such as:CH3-(CH2)11-C6H4-SO3–Na+(sodium N-dodecyl benzene sulphonate).
Cleansing Action of soap & Detergent
When soap dissolved in water, it forms a colloidal suspension in water in which soap molecules cluster together to form spherical structure that called as micelles.
Head portion (Hydrophilic) remains outward and tail portion (Hydrophobic) remains towards the oil (dirt) of soap molecule. Thus when dirt cloth agitated in soap solution. Micelles get dispersed in water. Solution now contains small globules of oil surrounded by detergent molecules.
In past, detergents cause pollution of rivers and water bodies. Long carbon chain present in detergent used earlier, contained lot of branching. These branched chain detergent molecules degraded very slowly by the action of micro-organism. Thus detergents persisted in water for long time and made water unfit for aquatic life.
|They are sodium or potassium salt of fatty acid.||They are sodium or potassium salt of sulphonic acid.|
|They have –COONa group.||They have –SO3Na group.|
|They are fully biodegradable.||Some detergent having branched hydrocarbon chain are non-biodegradable.|
|It may cause irritation to skin.||They do cause irritation to the skin.|
|Sodium stearates, sodium palmitate, etc.||Sodium dodecyl benzene sulphonate, sodium lauryl sulphate|
Physical Properties of Ethanol
- Pure ethanol is a colourless liquid
- It has a specific smell and burning taste.
- Its boiling point is 351 k which is higher than other alkane.
- It is soluble in water.
Chemical Properties of Ethanol
- Dehydration ethanol when heated with conc. H2SO4at 443k or Al2O3 at 623 K undergoes dehydration. Loses water molecule to form alkene.
C2H5OH H2C = CH2 + H2O
- Reaction with sodium
C2H5OH + Na C2H5ONa + H2
- Oxidation with alkaline KMnO4
C2H5OH +(O) alkaline KMnO4 CH3COOH + H2O
- Esterification: ethanol reacts with ethanoic in the presence of concentrated H2SO4 to form ethyl ethanoate and water. This compound is called ester. Esters are sweet fruity smelling compound because they occur in fruit. They are used in ice creams, cold drink & perfumes.
CH3COOH + C2H5OH conc. H2SO4 CH3COOC2H5 + H2O
- Combustion: Ethanol is a highly inflammable liquid i.e. it Catch fire very easily and burn with blue flame.
C2H5OH + 3O2 2CO2 + 3H2O
Harmful effects of Alcohol drinking
If ethanol mixed with methanol and consumed, it may cause loss of eye sight and serious poisoning.
- It cause addiction and may damage liver if taken regularly in large amount.
- Higher amount cause loss of body control & consciousness.
- Alcohol is added to petrol up to 20 %. The mixture is called gasol. It is clean fuel and creates less pollution.
- It is used in preparation of chloroform, iodoform, ethyl ethanoate etc.
- It (alcohol) used as hypnotic induce steep.
- Mixture of alcohol and H2O has lower freezing point than H2O, so used as antifreeze.
Uses of ETHANOL
- It is used as antiseptic for sterilising wounds.
- It is used in cough syrups, digestive syrups and in tonic.
- It is being mixed with petrol and used as fuel.
Physical Properties of ETHANOIC acid
- It is sour in taste and has boiling point 391 k.
- Acetic acid is soluble in water.
- Acetic acid freezes at 290 k. Thus in cold weather crystallization of acetic acid may takes place that they called as pure acetic acid is glacial acetic acid.
Chemical properties of ETHANOIC acid
- It is weak acid but it turns blue litmus to red.
- Reaction with metals.
CH3COOH + Na CH3COONa + H2
- Reaction with base.
CH3COOH + NaOH CH3COONa + H2O
- Reaction with carbonate.
CH3COOH +Na2CO3 CH3COONa+ CO2 + H2O
Uses of Ethanoic Acid
- It is used for making vinegar.
- It is used for making pickles.
It is a series of compounds which are derived from same general formula, having same functional group, similar chemical properties.
- Each member differs from successive member by—CH2
- Difference in molecular weight b/w two successive members is 14U.
- Same general formula.
- Same functional group.
- Similar chemical properties.
Catalyst: It is substance which increases the rate of reaction without itself undergoing any permanent chemical change e.g. Ni,Pt etc.
Saturated Hydrocarbons are those which have single bond such as:-CH4, C2H6,C3H8 etc.
Unsaturated Hydrocarbons are those which have double or triple bond such as:- C2H4,C3H6,C2H2 etc.