Class 10th Carbon And Its Compound \Chemistry Notes (Ncert/Cbse)

Carbon and Its Compounds

Carbon: Introduction

Atomic Number: 6
Electronic Configuration: 2, 4.
Valence electrons: 4
Property: Non-metal
Abundance:- Carbon is the 4th most abundant substance in universe and 15th most abundant substance in the earth’s crust.
Compounds having carbon atoms among the components are known as carbon compounds. Previously, carbon compounds could only be obtained from a living source; hence they are also known as organic compounds.

Bonding In Carbon:- The Covalent Bond

Bond formed by sharing of electrons is called covalent bond. Two of more atoms share electrons to make their configuration stable. In this type of bond, all the atoms have similar rights over shared electrons. Compounds which are formed because of covalent bond are called COVALNET COMPOUNDS.
Covalent bonds are of three types: Single, double and triple covalent bond.
Single Covalent Bond: Single covalent bond is formed because of sharing of two electrons, one from each of the two atoms.

Formation of hydrogen molecule (H₂)

Atomic Number of H = 1
Electronic configuration of H = 1.
Valence electron of H = 1
Hydrogen forms duet, to obtain stable configuration. This configuration is similar to helium (a noble gas).
Since, hydrogen has one electron in its valence shell, so it requires one more electron to form a duet. So, in the formation of hydrogen molecule; one electron from each of the hydrogen atoms is shared.

Formation of hydrogen chloride (HCl):

Valence electron of hydrogen = 1
Atomic number of chlorine = 17
Electronic configuration of chlorine: 2, 8, 7
Electrons in outermost orbit = 7
Valence electron = 7

Formation of chlorine molecule (Cl₂):

Valence electron of chlorine = 7

Formation of water (H₂O)

Valence electron of hydrogen = 1
Atomic number of oxygen = 8
Electronic configuration of oxygen = 2, 6
Valence electron = 6
Oxygen in water molecule completes stable configuration by the sharing one electron from each of the two hydrogen atoms.

Formation of Methane (CH₄)

Valence electron of carbon = 4
Valence electron of hydrogen = 1

Formation of Ethane (C₂H₆):

Double covalent bond: Double bond is formed by sharing of four electrons, two from each of the two atoms.

Formation of oxygen molecule (O₂):

Valence electron of oxygen = 2
In the formation of oxygen molecule, two electrons are shared by each of the two oxygen atoms to complete their stable configuration.
In oxygen, the total number of shared electrons is four, two from each of the oxygen atoms. So a double covalent bond is formed.

Formation of Carbon dioxide (CO₂):

Valence electron of carbon = 4
Valence electron of oxygen = 6
In carbon dioxide two double covalent bonds are formed.

Formation of Ethylene (C₂H₄):

Valence electron of carbon = 4
Valence electron of hydrogen = 1
Triple Covalent Bond: Triple covalent bond is formed because of the sharing of six electrons, three from each of the two atoms.

Formation of Nitrogen (N₂):

Atomic number of nitrogen = 7
Electronic configuration of nitrogen = 2, 5
Valence electron = 5
In the formation of nitrogen, three electrons are shared by each of the nitrogen atoms. Thus one triple bond is formed because of the sharing of total six electrons.

Formation of Acetylene (C₂H₂):

Properties of Covalent Bond:

• Intermolecular force is smaller.
• Covalent bonds are weaker than ionic bond. As a result, covalent compounds have low melting and boiling points.
• Covalent compounds are poor conductor of electricity as no charged particles are formed in covalent bond.
• Since, carbon compounds are formed by the formation of covalent bond, so carbon compounds generally have low melting and boiling points and are poor conductor of electricity.

Organic Compounds:
Initially, compounds of carbon could only be obtained from living sources and there was no way of synthesizing them. Hence, carbon compounds are also known as organic compounds.
Carbon forms a large number of compounds. So far, formulae of about 3 million carbon compounds are known.
Cause of formation of such a large number of compounds by carbon:-
(a) Carbon can form bonds with other carbon atoms. This property of carbon is known as CATENATION. Because of catenation, carbon can form a long chain; while making bond with other carbon atoms. Carbon can make single, double and triple bonds by catenation.
Example:
(c) Carbon can form branched chain; along with straight chain; while combining with carbon atoms, i.e. because of the property of catenation.
Example:-
(b) Carbon has four electrons in its outermost orbit. This gives carbon the valency which is equal to 4. That’s why carbon is tetravalent.
Carbon can also form bonds with other types of monovalent atoms; apart from carbon. Carbon can make long chain combining with other atoms also. For example; carbon can form bonds with oxygen, hydrogen, nitrogen, etc.
Carbon-carbon bonds are very stable, which makes the compounds of carbon stable.
Hydrocarbon:
Hydrogen + Carbon = Hydrocarbon.
Compounds; formed because of the combination of hydrogen and carbon are known as hydrocarbons.
Types of hydrocarbon: Saturated and Unsaturated.
Saturated hydrocarbons:
Hydrocarbons having single bonds are known as SATURATED HYDROCARBONS. Saturated hydrocarbons are known as ALKANE. These are also known as paraffin.
Example: Methane, Ethane, Propane, etc.
Unsaturated hydrocarbon: Unsaturated hydrocarbons are of two types – Hydrocarbon with double bond and hydrocarbon with triple bond.
Hydrocarbon with double bond: Hydrocarbons having at least one double bond are known as ALKENE
Example:-
Ethylene, Propylene, Butylene, etc.
Hydrocarbon with triple bond: Hydrocarbons having at least one triple bond are known as ALKYNE.
Example:
Ethyne, Propyne, Butyne, etc.
ALKANE: Hydrocarbons having only single bonds are known as alkane. These are saturated hydrocarbons. Alkane are also known as paraffin.
(a)


(b)


(c)


(d)


(e)


(f)


(g)


(h)


(i)


(j)

Carbon: Unsaturated Hydrocarbons: Alkene and Alkyne

ALKENE:- Hydrocarbons having at least one double bond between two carbon atoms are known as ALKENE.

Alkane – ane + ene = Alkene.
Name of this compound: Since, hydrocarbon having one carbon atom is known as Methane.
Thus, Methane – ane + ene = Methene
But, alkene does not exist with one carbon atom, thus, methene does not exist.
In similar way, other Alkenes are formed.

ALKYNE: Hydrocarbons having at least one triple bond between two carbon atoms are known as alkyne.

Alkane – ane + yne = Alkyne
Similarly,
Ethane – ane + yne = Ethyne
Propane – ane + yne = Propyne
Butane – ane + yne = Butyne
Pentane – ane + yne = Pentyne
In similar way other Alkynes are formed.

Cyclic Hydrocarbon:-

Carbon can form cyclic structure combining with carbon atoms. Such hydrocarbons are known as cyclic hydrocarbon.

Carbon: Functional Group And Nomenclature of Hydrocarbon

Functional Group:

Single atom or group of atoms, that have similar chemical properties are called functional group. For example: Halogen group, Carboxyl group, Aldehyde group, etc.

Alkyl group: -R is known as alkyl group.

Halogen group: Halogen group is also known as halo group. –Cl (Chloro),-Br(Bromo),-I(Iodo) are halogen or halo group.
Alcohol: -OH is known as alcohol group.
Aldehyde: -CHO is known as aldehyde group.

Hydrocarbons belong to same group have similar properties.

Nomenclature of Carbon Compounds:

International Union of Pure and Applied Chemistry (IUPAC) decided some rules to name the carbon compounds. This was done to maintain the uniformity throughout the world. Names which are given on this basis are popularly known as IUPAC name.
(1) Identify the number of carbon atoms in carbon compound. Name the carbon compounds according to the number of carbon atoms.

Example:-

Saturated hydrocarbon having one carbon atom is named as Methane. Saturated hydrocarbon having two carbon atoms is named as Ethane.
Unsaturated hydrocarbon with double bond having two carbon atoms is named as Ethene.
Unsaturated hydrocarbon with triple bond between carbon atoms is named as Ethyne.
(2) If the structure has branched chain, identify the longest chain and then identify the number of carbon atoms.

In figure (a) the longest chain has eight carbon atoms, and thus the name of parent compound would be octane. In figure (b) longest chain has nine carbon atoms, and thus the name of parent compound would be nonane.

Identify the longest chain. Then number the carbon atoms in such a fashion that the functional group; if any; would come at the lowest number.
In the given figure (c), while counting from right to left (in red color), branched chain which is functional group falls at the fourth position. On the other hand, while counting from left to right, the branched chain falls at the fifth position. In this case, the numbering from right to left is taken because then only the functional would be at the lowest position.
(3) In case of a functional group present, write the prefix or suffix of the functional group according to the table given here. Then write the name of the parent compound.

Nomenclature of Alkane:-

Example – (1)

Common name:- Iso-butane.
IUPAC Name:
Number of carbon atoms in the longest chain = 3.
A methyl group is present at carbon number 2.
So, IUPAC Name is 2-methyl propane.
Example:- (2) -

It’s common name is Iso-pentane.

IUPAC Name:

Numbering of carbon atoms is done in two ways, i.e. from left to right and from right to left.
The number of carbon atoms in the longest chain = 4.
A methyl group (functional group) is attached with this chain.
Thus, name of parent compound is Butane.
In the numbering from left to right functional group falls at second number while in the numbering from right to left; the functional group falls at 3rd position.
Therefore, IUPAC name of this compound is 2-methyl butane.
Example:(3):-

Common name: NeopentaneAC Name: There are three carbon atoms in longest chain.
Two methyl groups are present at second (2) carbon atom. (Di is used as prefix for two).
Therefore, IUPAC Name: Di-methyl propane.

Naming of hydrocarbon with Halo group:

Common name: Methyl chloride
There is one carbon atom in this compound. So its parent name is Methane.
One chloro group is present in this compound.
So, its IUPAC name is Chloro-methane.

Common Name: Propyl chloride. AC Name:
Number of carbon atoms = 3
Functional group: Chloro
Thus, IUPAC Name is Chloro-propane.

Common name: Propyl brominde
IUPAC Name: Bromo-propane

Number of carbon atoms: 6 (six) ctional group: Iodo
Common Name: Hexyl iodide.
IUPAC Name: Iodo-hexane.

Number of carbon atom: 1 (one)
Functional group: Alcohol (suffix : ol)
Common name: Methyl alcohol.
IUPAC Name:
Methane – e Methane – e + ol = Methanol.

Number of carbon atoms: 2 (two)
Functional group: Alcohol
Common name: Ethyl alcohol.
IUPAC Name: EthanoIUPAC Name: Ethanol.

Number of carbon atoms: 6 (six) l group: Alcohol
Common name: Hexyl alcohol.
IUPAC IUPAC Name: Hexanol.

Naming of Aldehyde group (-CHO):

The suffix of aldehyde group is “al”.
IUPAC name of alkane having aldehyde group is written as follows:
Alkane – e + al = Alkanal
Methane – e + al = Methanal
Ethane – e + al = Ethanal, and so on.

Number of carbon atom: 1 (one)
IUPAC Name: Methanal
Common name: Formaldehyde.

Number of carbon atoms: 2 (Two)
Functional group: Aldehyde
IUPAC Name: Ethanal
Common name: Acetaldehyde

Number of carbon atoms: 7 (seven) C Number of carbon atoms: 7 (seven) C Name: Heptanal.

Naming of Carboxylic Acid (– COOH):

Suffix for carboxylic acid is ‘oic acid”.
Thus an alkane having carboxylic acid is named as: >Example:
Methane – e + oic acid = Methanoic acid
Ethane – e + oic acid = Ethanoic acid.

Number of carbon atom: 1(one)
IUPAC Name: Methanoic acid.
Common name: Formic acid.

Number of carbon atoms: 2 (two)
Common Name: Acetic acid.
IUPAC Name: Ethanoic Acid

Number of carbon atoms: 5 (five)
Functional group present: Carboxylic acid
IUPAC Name: Pentanoic acid.

Naming of Ketone (– CO –):

Suffix for ketone group: ‘one’.
A hydrocarbon having ketone group is named as:

Number of carbon atoms: 3 (three)
Functional group: Ketone group
Thus, IUPAC Name is Propanone.
Common name: Dimethyl ketone.

Number of carbon atoms: 5 (five)
Functional group: Ketone group
Thus, IUPAC Name: Pentanone
General name: Diethyl ketone

Number of carbon atoms: 6 (six)
IUPAC Name: Hexanone
General name: Ethyl propyl ketone

Homologous Series:

Series of compounds with same general formula and functional group is known as homologous series. Compounds belonging to the same homologous series show similar properties. Compounds of homologous series differ by CH₂ from their consecutive members. Each subsequent compound in a homologous series differs by 14 au.
Example:
Alkanes, such as, Methane, Ethane, Propane, Butane, etc. belong to same homologous series.

Similarly, all alkenes and alkSimilarly, all alkenes and alkynes belong to same homologous series.

Properties of Compounds of Same Homologous Series

(a) Compounds of same homologous series have same general formula.
(b) Compounds of same homologous series differ from their consecutive members by one carbon atom and two hydrogen atoms, homologous series differ from their consecutive members by one carbon atom and two hydrogen atoms, i.e. by CH₂
(d) Compounds of same homologous series have same chemical properties.
(e)Compounds of same homologous series differ by physical properties with increase or decrease in molecular mass.

Carbon: Chemical Properties of Carbon Compounds

Combustion or Combustion Reaction:

Carbon and carbon compounds gives carbon dioxide, vapor, heat and light on burning in air.

Example:

Oxidation:

In combustion reaction, carbon compounds are oxidized in the presence of oxygen. The following example is different because alkaline KMnO₄ is the oxidizing agent in this reaction.

Addition Reaction:-

Formation of larger molecules by addition of more radicals is known as addition reaction.

Ethene is converted into ethane when heated with the catalyst nickel.

Substitution Reaction:

Replacement of a functional group or any atom by another atom or functional group is known as substitution reaction. Substitution reactions are single displacement reactions.
When methane reacts with chlorine gas in the presence of sunlight, it gives chloromethane and hydrogen chloride.

Some Important Carbon Compounds: Ethanol and Ethanoic Acid:

Ethanol (C₂H₅OH):

• Ethanol is commonly known as alcohol and spirit.
• General name of ethanol is ethyl alcohol.
• Ethanol is the main constituent of all alcoholic drinks
• Ethanol is soluble in water
• Ethanol is a very good solvent
• Ethanol is used in manufacturing of medicines, such as tincture iodine, cough syrup, etc.
• Taking even small quantity of pure ethanol may prove lethal
• Taking dilute ethyl alcohol can cause drunkenness
• Reaction of ethanol with sodium metal:


• General name of ethanoic acid is acetic acid.
• Melting point of ethanoic acid is 290K.
• Ethanoic acid freezes in winter and hence it is also known as glacial acetic acid.
• Ethanoic acid is a colorless liquid.
• 5% to 8% solution of acetic acid in water is known as vinegar.
• Vinegar is used as preservative in pickles.
• Carboxylic acids are weak acid compared to mineral acids.

Reaction of ethanoic acid with base:

Ethanoic acid gives sodium acetate when it reacts with sodium hydroxide.

The IUPAC name of Ethyl acetate is Ethyl Ethanoate. Ethyl acetate is also known as ester.
Ester is a sweet smelling compound. It is used in making perfumes and as a flavouring agent.
When ethyl ethanoate reacts with a base or acid, it gives back ethanol and ethanoic acid.

This reaction is called saponification, since it is used in making of soap.

Hydrolysis of ester (Ethyl ethanoate):

Ethyl ethanoate gives parent alcohol and sodium ethanoate when heated with sodium hydroxide solution.

Saponification:

Ester of higher fatty acids gives sodium salt of higher fatty acid; when heated with glycerol and sodium hydroxide. Sodium salts of higher fatty acid are known as soaps. This reaction is called saponification (soap making).

Reaction of ethanoic acid with sodium carbonate and sodium bicarbonate:

Ethanoic acid gives sodium acetate, water and carbon dioxide when reacts with sodium carbonate or sodium bicarbonate (sodium hydrogen carbonate).

Soaps and Detergents:

Soap: Ester of higher fatty acids is called soap. It is manufactured by the reaction of easter of higher fatty acid with sodium hydroxide. The sodium salt so formed has cleansing property.
Detergent: Soap cannot form lather in hard water. To overcome this problem, detergents were introduced. Detergent is also known as soapless soap.
Detergent is sodium salt of benzene sulphonic acid or sodium salt of long chain alkyl hydrogen sulphate.

Cleansing action of soap:

Soap molecule has two ends. One end is hydrophilic and another end is hydrophobic. In other words, one end is lipophobic (hydrophilic) and another end is lipophilic (hydrophobic). When soap is dissolved in water and clothes are put in the soapy solution, soap molecules converge in a typical fashion to make a structure; called micelle. The hydrophobic ends of different molecules surround a particle of grease and make the micelle; which is a spherical structure. In this, the hydrophilic end is outside the sphere and hydrophobic end is towards the centre of the sphere. That is how, soap molecules wash away dirt and grease by making micelles around them.


Soap and Hard Water: Hard water often contains salts of calcium and magnesium. Soap molecules react with the salts of calcium and magnesium and form a precipitate. This precipitate begins floating as an off-white layer over water. This layer is called scum. Soaps lose their cleansing property in hard water because of formation of scum. Detergents are used; instead of soaps; in hard water to overcome the problem. Detergents are usually ammonium or sulphonate salts of carboxylic acids. The charged ends of these compounds do not form precipitate with calcium or magnesium salts in hard water. Hence, detergents retain their cleansing property in hard water.



 Download Notes From Given Link Below:

Download Notes Now

Read More