Carbon and its compounds (class 10) are one of the most important topics for your board exams. Here, we have provided all the important notes of carbon and its compounds (class 10) which will help you to understand this chapter and hence excel your marks.
Basic of Carbon and Its Compounds
- CARBON: Carbon is an element (non-metal)
- SYMBOL: “C”
- ISOTOPES: 6C12, 6C13, 6C14
- VALANCY: 04
- ATOMIC NUMBER: 06
- ALLOTROPS: Diamond, Graphite, Fullerenes.
- ATOMIC MASS: 12
- VALANCE ELECTRONS: 04
Occurrence Of Carbon
Carbon is found :
- In Atmosphere
- Inside the earth’s crust and in the living Organisms
- In fuels like wood, coal, charcoal, coke, petroleum, natural gas, biogas, etc.
- In the free state as Diamond, Graphite, and Fullerenes.
- Carbon can be detected in the compounds like Carbonates and hydrogen carbonates.
Bonding in Carbon(Covalent Bond)
The atomic number of carbon is 6, and hence its electronic configuration is 2 (in K shell) , 4 (in L shell) with 4 valence electrons. It can attain stability by gaining 4 electrons, by losing 4 electrons, or by sharing the 4 electrons with others or by atoms.
Reason for covalent bonding of Carbon:
- It does not gain/take 4 electrons because it is very difficult for the 6 protons to hold the charge of 10 electrons.
- It does not lose/give 4 electrons because it needs a large amount of energy to lose 4 electrons.
Therefore, it shares 4 electrons with other atoms to attain stability resulting in the formation of covalent bonds.
Note: Since a carbon atom needs 4 electrons to attain stability, therefore its valency is 4 and it is tetravalent.
The bond formed by the sharing of electrons (between two or more atoms) is called covalent bonds.
There are three types of covalent bonds based on several electron pairs to be shared :-
- Single Covalent Bond
- Double covalent Bond
- Triple covalent Bond
Single Covalent Bonds
The sharing of one pair of electrons between two atoms of the same or different element resulting in the formation of a single covalent bond.
Example – Formation of single covalent bond in hydrogen molecules (H2).
Double covalent bonds:
The sharing of two pairs of electrons between two atoms (of the same or different elements) resulting in the formation of a double covalent bond.
Example – Formation of double covalent bond in an oxygen molecule (02).
Triple covalent bonds
The sharing of three pairs of electrons between two atoms (of the same or different element) resulting in the formation of a triple covalent bond.
Example – Formation of triple covalent bond in Nitrogen molecule (N2).
Versatile Nature Of Carbon Atom:
Two important properties of the carbon atoms enable carbon to form an enormous number of compounds. These properties are:
- Catenation: The property of the carbon atom to form a bond with another atom of carbon is called catenation. Just like Silicon ,Carbon form compounds with hydrogen up to seven or eight atoms of silicon.
- Tetravalency: Having a valency of 4 carbon atoms is capable of bonding with an atom of oxygen, hydrogen, nitrogen, sulfur, chlorine, and other elements.
The smaller size of the carbon atom enables the nucleus to hold the shared pair of electrons strongly, thus carbon compounds are very stable in general.
Allotropes Of Carbon:
Allotropes are the different forms of an element which has different physical properties or structure but have the same chemical properties. An element can have more than one different form.
Carbon exists in 2 types of allotropic forms which are:
- Crystalline form (Example – Diamond, Graphite, Fullerenes).
- Non-crystalline form (Example – Coal, Charcoal, and Lampblack).
Structure Of Diamond
In the structure of diamond, each carbon atom is bonded with the other 4 carbon atoms by strong covalent bonds to form a three-dimensional structure called Tetrahedral structure.
There is no free electron to conduct electricity. The strong covalent bond between the carbon atom makes it the world’s hardest substance.
Properties of Diamond
Some important properties of diamond are as follows:-
- Diamond is a transparent and colorless substance with extraordinary shine due to its high refractive index.
- It is one of the hardest natural substances on earth due to its strong covalent bonds and tetrahedral structure.
- Diamond is also a very pathetic conductor of electricity because of the absence of free electrons.
- Due to its complex structure diamond has very high melting and boiling point.
- It burns on strong heating to form carbon dioxide gas.
Uses of diamond
Uses of diamond cute as follow:-
- Diamond is used as a cutting instrument like a glass cutter, marble cutter, etc.
- It is also used in ornaments or jewelry.
- Diamond absorbs harmful radiations, hence it is used in space satellites to make radiation-proof windows.
Structure Of Graphite
In the structure of graphite, each carbon atom is bonded with the other three carbon atoms to form hexagonal rings. These hexagonal rings combine to form a flat layer (sheet) of carbon.
These layers of carbon atoms are held by weak van der Waal” forces so that these layers can slide over one another.
Since in the structure of graphite each carbon atom is bonded with the other three carbon atoms. Therefore one electron remains free to conduct electricity. Hence it is a brilliant conductor of electricity.
Properties of graphite
Properties of graphite are as follows:
- It is a greyish-black Opaque Substance.
- It is lighter than diamond.
- It is slippery in touch.
- On strong heating graphite burns in the fire and releases CO2 (carbon dioxide).
Uses of graphite
- Graphite is used as a solid lubricant in electric motors.
- It is used in the lid of a pencil.
- Graphite rods also have a very important use in nuclear reactors as they absorb the excess neutrons.
- It can be used in the making of graphene sheets. These sheets are said to be 100 times lighter than steel.
Fullerenes are the recently discovered allotropic form of Carbon that was prepared by H.W Kroto, Smalley, and Robert curt by the action of the laser beam on the vapour of graphite.
The most commonly known fullerene contains 60 carbon atoms and is known as Buckminster fullerenes. Fullerene (C60) was named after the American architect Buckminster Fuller because its structure resembled the framework of a dome-shaped hall, designed by fuller for the large international conference.
Structure Of Fullerene
Fullerene (C60) seems like a football-shaped spherical molecule that contains 60 carbon atoms, that are arranged within the sort of interlinking hexagonal and pentagonal rings of carbon atoms. One C60 molecule contains 20 hexagonal rings and 12 pentagonal rings of a carbon atom.
Properties Of Fullerene
Some important properties of fullerene are as follows:-
- These are dark solids at room temperature.
- These are not too hard and also too soft.
- On burning, fullerene only produces CO2 i.e. carbon dioxide gas.
The compounds continaing carbon and hydrogen atoms and are found in living organisms or are produced by living organisms are known as organic compounds
Methane(CH4) , Ethene(C2H4) , Trichloromethane(CHCL3) , Urea[CO(NH2)2] , etc.
Types of Organic Compounds:
- Carboxylic acids(Organic acids)
Hydrocarbons are those compunds which only contain Hydrogen and Carbon atoms.
Types of Hydrocarbons:
Saturated Hydrocarbons OR Alkanes
- Those hydrocarbons in which carbon atoms are connected by single bonds is called saturated hydrocarbon.
- General Formula : CnH2n+2
|Name of Alkane||Number of Carbon atoms(n)||Molecular formula|
Unsaturated Hydrocarbons (Alkenes and Alkynes)
Those hydrocarbons in which carbon atoms are connected by a double or triple bond is called unsaturated hydrocarbon.
- In this compund two carbon atoms are connected by a double bond.
- General formula : CnH2n
|Name of Alkene||Number of Carbon atoms(n)||Molecular formula|
- In this compund two carbon atoms are connected by a triple bond.
- General formula : CnH2n-2
|Name of Alkyne||Number of Carbon atoms(n)||Molecular formula|
The group formed by the removal of one hydrogen atom from an alkane molecule is called an alkyl group.
Examples :- Methyl group(CH3—) , Ethyl group(C2H5—) , etc.
Naming of Alkyle Group : Root term + “yl”
Compounds having the same molecular formula but different structural formulas and properties are known as Isomers and this phenomenon is known as Isomerism.
- Structural Isomerism: Compounds having an equivalent formula but different arrangement of atoms are called Structural isomers.
Examples of Structural Isomerism :
Butane and isobutane (C4H10)
2-Butene and 1-Butene (C4H8)
Propane and propene (C3H8) , etc.
Isomer of Butane:
A series of organic compounds/elements having the same kind of functional group, chemical properties, and their successive members differ by a CH2 unit or 14 mass units are known as Homologous series.
Characteristic of Homologous Series
- Each successive members in a homologous series differ by CH2 unit or 14 mass unit.
- All the members of the homologous series have the same functional group.
- All the members of the homologous series display matching chemical properties.
- All the members of a homologous series can be respresented by the same general formula.
A atom or group of atoms present in saturated hydrocarbon(alkane) other than hydrogen and single bond carbon is called Functional group.
Some Important functional groups present in organic compunds are
- Halo Group(—Cl , —Br, —I)
- Alcohol group(—OH)
- Ketone group(—CO—)
- Carboxylic Acid group(—COOH)
- Alkene group(=C=C=)
- Alkyne group(—C≡C—)
|S.no||Functional group||Their formula||Example|
Nomenclature of Organic Compounds
Just like a human can have two names , Organic compounds have two names : 1) common names , 2) official names(IUPAC names)
IUPAC set some rules for naming various compounds. The rules are :-
- Number of carbon is indicated by :
|No of carbon atoms(n)||Root term|
2) . Different types of hydrocarbon is indicated by using different suffix and prefix.
|Types of compound||Prefix||Suffix|
3) Then Name of Compund = Prefix + Root term + Suffix
Chemical Properties of Carbon Compounds:
The important chemical properties are as follows:
- Complete combustion of carbon compounds in the air leads to the production of carbon dioxide water, heat, and light. This is called combustion.
CH3CH2OH(l) + O2(g) → CO2(g) + H2O(l) + Heat and light
- Carbon burns in air/oxygen to produce carbon dioxide, heat (energy) and light.
C(s) + O2(g) → CO2(g) + Heat and light
- Saturated hydrocarbons burn with a blue flame if sufficient air or oxygen is available.
CH4(g) + 2O2(g) → CO2(g) + 2H2O(l) + Heat and light
- In presence of a limited supply of air, saturated hydrocarbon forms a sooty flame.
- Unsaturated hydrocarbons when burnt produce a yellow smoky flame.
- The gas and kerosene stove used at home has an inlet for air so that, burnt to give clean blue flame.
- Due to the presence of a small amount of nitrogen and sulfur, coal and petroleum produce carbon dioxide with oxides of nitrogen and sulfur which are major pollutants.
Oxidation of ethanol in the presence of oxidizers produces ethanoic acid.
- Oxidizing Agent: Some substances are capable of adding oxygen to others, which are known as Oxidising Agent.
Example: Alkaline KMnO4 (or KMnO4—KOH)
Acidified K2Cr2O7 (or K2Cr2O7—H2SO4)
KMnO4 – Potassium permanganate
K2Cr2O7 – Potassium dichromate
- The addition of dihydrogen with unsaturated hydrocarbon in the presence of catalysts such as nickel or platinum or palladium is known as a Hydrogenation (addition) reaction.
Catalyst: Substances that cause a reaction to occur or proceed at different rates without consuming in it are called a catalyst. For example; Ni, Pt, Pd, etc.
The process of converting vegetable oil into solid fat (vegetable ghee) is called the Hydrogenation of Oil.
Vegetable fats are saturated fats that are harmful to health.
Vegetable oil containing unsaturated fatty acids is good for health.
Replacement of 1 or greater hydrogen atoms of a natural molecule with the aid of using any other atom or group of the atom.
Substances that remove water from ethanol (alcohols) are known as Dehydrating agents. For example; Cone. H2SO4.
Uses: As a solvent, as an antiseptic (tincture iodine), as an anti-freeze in automobiles.
Physical Properties of Ethanol
- It a volatile and colourless liquid.
- Low Boiling point : 351K
- It is lighter than water and mixes with water in any proportion.
- It is a neutral compund and has no effext on any litmus solution.
Chemical properties of Ethanol
- Ethanol is a highly inflammable liquid.
- It reacts with sodium to form sodium ethoxide(C2H5O–Na+) and hydrogen gas.
- In presence of alkaline petassium permanganate(KMnO4) solution , it get oxidised to form ethanoic acid(CH3COOH).
Ethanoic Acid (CH3COOH)
Commonly known as Acetic acid. This is also known that 5-8% of ethanoic acid when mixed in water is called Vinegar.
Physical Properties of Ethanoic Acid
- It is a colorless, pungent-smelling liquid.
- Miscible with water in all proportions.
- The melting factor of natural ethanoic acid is 290 K.
- The boiling point is 391K.
- It frequently freezes in very cold climates so named glacial acetic acid.
Chemical properties of Ethanoic Acid
- It turns blue litmus red.
- It reacts with carbonates and hydrogencarbonates to evolve CO2 with formation of salt and water.
- It reacts with alcohols to form esters.
Soap and Detergent
Commonly, soaps are in the form of sodium or potassium salts of long-chain fatty acids.
General formula: —COO–Na+
Ammonium and sulphonate salts of long-chain fatty acids are referred to as Detergent.
General formula: —SO3–Na+ OR —SO4–Na+
Hard and Soft Water:
- Water that doesn’t produce lather with cleaning soap with ease is known as Hard water
- Water which produces lather with cleaning soap is known as Soft Water.
The hardness of water is due to the presence of bicarbonates, chlorides, and sulfate salt of calcium and magnesium.
Advantages of Detergents
- Detergent is better than soap for washing clothes because soap doesn’t work well in hard water.
- Hard water causes soap to make a white, curdy substance called Scum.
Differences between Soaps and Detergents
|Soaps are the sodium salts of the long chain carboxylic acids.||Detergents are the sodium salts of long chain benezene sulphoinic acids.|
|General formula: —COO–Na+||General formula: —SO3–Na+ OR —SO4–Na+|
|Not beneficial for Hard water.||It work even when water is hard.|
|All areBiodegradable.||Some are Non-biodegradable.|
|It is relatively weak effect on washing.||It have a strong cleansing action.|
Cleansing Action of Soaps and Detergents:
Both soaps and detergents contain two parts. A large hydrocarbon element that’s hydrophobic (water-repelling) in nature and a shorter ionic element that’s hydrophilic (water-attracting) in nature.
The hydrocarbon a part of the cleaning soap molecule links itself to the oily (dust) drop and ionic stop orients itself toward the water and takes a round shape referred to as micelles. The cleaning soap micelles enable in dissolving the dust in water and washing our clothes.
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Some important topics for class 10th board exams:-
Chapter 5 Periodic Classification of Elements Class 10 Notes
Chapter 6 Life Processes Class 10 Notes
I hope these notes for carbon and its compounds will help you understand the chapter better and you’ll perform well in your exams.
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