Here are detailed notes on Carbon and Its Compounds for Class 10, based on the NCERT syllabus:

1. Introduction to Carbon

Carbon (C) is a non-metal, located in Group 14 of the Periodic Table.

It has an atomic number of 6, with 4 electrons in its outermost shell (2, 4).

It exhibits catenation, the ability to form bonds with itself, leading to a variety of compounds.

Carbon forms covalent bonds by sharing its four valence electrons with other atoms.

2. Covalent Bonding

Covalent bonds are formed when atoms share electrons.

Carbon can form single, double, or triple covalent bonds, depending on the number of electrons shared:

Single bond: Sharing one electron pair (e.g., in methane, CH₄).

Double bond: Sharing two electron pairs (e.g., in ethene, C₂H₄).

Triple bond: Sharing three electron pairs (e.g., in ethyne, C₂H₂).

3. Allotropes of Carbon

Carbon exists in different allotropes due to its ability to bond in various ways:

Diamond: Each carbon atom is tetrahedrally bonded to four other carbon atoms. It’s extremely hard and has a high melting point.

Graphite: Carbon atoms form layers of hexagonal structures with weak forces between layers, making it soft and slippery.

Fullerenes: These are spherical molecules (e.g., C₆₀), with each carbon atom bonded to three others.

4. Versatile Nature of Carbon

Carbon can form chains, branched chains, and rings of different lengths.

This property, combined with catenation and multiple bonding, makes carbon compounds extremely versatile.

5. Hydrocarbons

Hydrocarbons are organic compounds made of only carbon and hydrogen. They are classified into:

Saturated hydrocarbons (Alkanes): Carbon atoms connected by single bonds (e.g., Methane - CH₄, Ethane - C₂H₆).

Unsaturated hydrocarbons: These have one or more double or triple bonds.

Alkenes: At least one double bond (e.g., Ethene - C₂H₄).

Alkynes: At least one triple bond (e.g., Ethyne - C₂H₂).

6. Nomenclature of Carbon Compounds

The IUPAC system is used to name carbon compounds based on the number of carbon atoms and the functional groups.

Meth-: 1 carbon atom

Eth-: 2 carbon atoms

Prop-: 3 carbon atoms

But-: 4 carbon atoms, etc.

Suffixes indicate the type of bond (-ane, -ene, -yne).

7. Functional Groups

Functional groups are atoms or groups of atoms attached to the carbon chain, replacing hydrogen, that determine the chemical properties of the compound:

Alcohol (-OH): E.g., Methanol (CH₃OH)

Aldehyde (-CHO): E.g., Ethanal (CH₃CHO)

Carboxylic acid (-COOH): E.g., Ethanoic acid (CH₃COOH)

Ketone (-CO): E.g., Propanone (CH₃COCH₃)

Halogens (–X): E.g., Chloroethane (C₂H₅Cl)

8. Chemical Properties of Carbon Compounds

1. Combustion: Carbon compounds burn in the presence of oxygen to produce carbon dioxide, water, and energy. For example:

CH₄ + 2O₂ → CO₂ + 2H₂O + Heat

2. Oxidation: Alcohols can be oxidized to form aldehydes and carboxylic acids. For example:

Ethanol + Alkaline KMnO₄ → Ethanoic acid

3. Addition reactions: Unsaturated hydrocarbons undergo addition reactions, where reactants add across the multiple bonds. E.g., the hydrogenation of ethene to form ethane.

4. Substitution reactions: In saturated hydrocarbons, one hydrogen atom is replaced by another atom or group in the presence of sunlight. For example:

CH₄ + Cl₂ → CH₃Cl + HCl (in sunlight)

9. Important Compounds of Carbon

1. Ethanoic Acid (Acetic Acid):

Chemical formula: CH₃COOH

It is a weak acid and is the main component of vinegar.

It reacts with alcohol to form esters (esterification reaction).

2. Ethanol (Ethyl Alcohol):

Chemical formula: C₂H₅OH

It is commonly used as an industrial solvent and in alcoholic beverages.

It undergoes oxidation to form acetic acid.

10. Soaps and Detergents

Soaps: Sodium or potassium salts of long-chain carboxylic acids. They clean by emulsifying oil or grease in water.

Detergents: Synthetic compounds with cleaning properties similar to soap, but they can work in hard water.

1. Oxidation Reaction

An oxidation reaction involves the gain of oxygen or the loss of hydrogen by a substance. In organic chemistry, oxidation generally means adding oxygen or removing hydrogen from a compound.

Examples of Oxidation Reactions:

Ethanol to Ethanoic Acid: Ethanol (C₂H₅OH) can be oxidized to ethanoic acid (CH₃COOH) using oxidizing agents like alkaline potassium permanganate (KMnO₄) or acidified potassium dichromate (K₂Cr₂O₇).

Reaction:

Oxidation of Alkenes: Unsaturated hydrocarbons like alkenes (e.g., ethene, C₂H₄) can also be oxidized to form diols (compounds with two -OH groups).

Reaction:

Key Points:

Oxidation can involve the addition of oxygen or removal of hydrogen.

Oxidizing agents like potassium permanganate (KMnO₄) and potassium dichromate (K₂Cr₂O₇) are used to facilitate these reactions.

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2. Substitution Reaction

A substitution reaction involves the replacement of one atom or a group of atoms in a molecule by another atom or group. In organic chemistry, these reactions are common with saturated hydrocarbons (alkanes), where one or more hydrogen atoms are substituted by halogens (e.g., chlorine, bromine) under specific conditions.

Example of Substitution Reaction:

Chlorination of Methane: In the presence of sunlight, methane (CH₄) reacts with chlorine (Cl₂) to form chloromethane (CH₃Cl), and one of the hydrogen atoms is substituted by a chlorine atom. This reaction can continue to form more substituted products like dichloromethane (CH₂Cl₂), trichloromethane (CHCl₃), and tetrachloromethane (CCl₄).

Reaction:

\text{CH}_4 + \text{Cl}_2 \xrightarrow{\text{sunlight}} \text{CH}_3\text{Cl} + \text{HCl}

Mechanism:

The substitution reaction typically occurs through a free radical mechanism, where:

1. Initiation: Chlorine molecules split into chlorine radicals (Cl•) under sunlight.

2. Propagation: These radicals then react with methane, replacing a hydrogen atom and forming new radicals.

3. Termination: The reaction ends when two radicals combine, forming a stable product.

Key Points:

Substitution reactions typically occur in alkanes.

These reactions require specific conditions, such as sunlight, and involve the replacement of hydrogen atoms by halogens.

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Summary:

Oxidation Reaction: Involves the addition of oxygen or removal of hydrogen. For example, ethanol gets oxidized to ethanoic acid.

Substitution Reaction: Involves the replacement of one atom or group by another, such as the substitution of hydrogen by chlorine in methane to form chlo

romethane.

Let me know if you'd like more clarification on any point!

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This should c

over the key points about carbon and its compounds as per the NCERT Class 10 syllabus. Let me know if you need explanations on any specific topic!