Class 10 Science Chapter 4 NCERT Book PDF Download 2026-27

The NCERT Book for Class 10 Science Chapter 4 Carbon and its Compounds is the official CBSE textbook chapter, free to read and download for the 2026-27 session. This chapter explains the covalent bond, the allotropes of carbon, the versatile nature of carbon through catenation and tetravalency, saturated and unsaturated compounds, functional groups, the homologous series, and the chemistry of ethanol and ethanoic acid.

• Official NCERT textbook PDF of Chapter 4, with every activity, figure, in-text question and exercise exactly as printed.
• Covers covalent bonding, allotropes of carbon, catenation and tetravalency, structural isomers, functional groups, the homologous series, nomenclature, and the reactions of ethanol and ethanoic acid.
• Aligned with the 2026-27 CBSE Class 10 Science syllabus, useful for board exam revision and as the base text for the solutions and notes.

This page hosts the official NCERT Class 10 Science textbook chapter, mapped to the 2026-27 CBSE syllabus and checked page by page against the printed Carbon and its Compounds chapter.

What the NCERT Book for Class 10 Science Chapter 4 Carbon and its Compounds Covers

The PDF above is the complete official NCERT chapter for 2026-27. It moves from how carbon forms bonds, to the allotropes of carbon, why carbon makes millions of compounds, how they are named, and the chemistry of ethanol and ethanoic acid.

• Covalent bonding: how carbon shares its four valence electrons to form single, double and triple bonds.
• Versatile nature: catenation and tetravalency, the two reasons carbon forms so many compounds.
• Functional groups and homologous series: alcohols, aldehydes, ketones and carboxylic acids, and families differing by a CH₂ unit.
• Important compounds: ethanol, ethanoic acid, and the cleaning action of soaps and detergents.

Carbon and its Compounds Class 10 Science Full Chapter Video

Source: Magnet Brains on YouTube

Covalent Bonding in Carbon: The Covalent Bond in Class 10 Science

Carbon has the electron arrangement 2,4, giving it four valence electrons. Gaining or losing four electrons is too difficult, so carbon shares its electrons to form covalent bonds, a bond formed by sharing a pair of electrons between two atoms.

A single bond shares one electron pair (CH₄), a double bond shares two (O₂), and a triple bond shares three (N₂). The standard example is methane, CH₄: carbon shares one electron pair with each of four hydrogens. Because no ions form, covalent compounds differ from ionic compounds:

• Low melting and boiling points: forces between molecules are weak, so little heat is needed to separate them.
• Poor conductors: no free ions or electrons form, so most carbon compounds do not conduct electricity.
• Mostly molecular: they exist as separate molecules, unlike the giant lattices of ionic solids.

Allotropes of Carbon in Class 10 Science Chapter 4

Carbon occurs in different forms with very different physical properties, called allotropes. The difference is only how the carbon atoms are arranged, which is why the same element can be the hardest substance and also a soft, slippery conductor.

In diamond every carbon uses all four bonds in a tight 3D cage, making it very hard. In graphite each carbon bonds to only three others in flat sheets, and the free fourth electron is why graphite conducts electricity even though it is a non-metal. Both are the same element; only their physical properties differ.

The Versatile Nature of Carbon: Catenation and Tetravalency

Why does carbon form millions of compounds? The NCERT book gives two reasons, and naming both is worth full marks:

• Catenation: carbon bonds to other carbon atoms to form long chains, branched chains and rings; the C-C bond is strong, so chains do not break easily.
• Tetravalency: carbon has a valency of four, so each atom bonds with four others, of carbon or of elements like hydrogen, oxygen, nitrogen and the halogens.

A third reason is the small size of the carbon atom, which lets the nucleus hold the shared electrons strongly. Molecules of only carbon and hydrogen are called hydrocarbons.

Carbon skeletons can be straight chains, branched chains, or rings such as cyclohexane and benzene. Compounds with the same molecular formula but different structures are called structural isomers; the textbook shows two skeletons for butane, C₄H₁₀. Be ready to draw both.

Saturated and Unsaturated Carbon Compounds in Class 10 Science

A saturated compound has only single bonds, while an unsaturated compound has at least one double or triple bond. This difference decides how reactive the compound is and how it is named.

The general formula for alkenes is C_nH_2n. The simplest members are ethane, ethene and ethyne. Saturated hydrocarbons are not very reactive; unsaturated ones are more reactive, which is why ethene and ethyne undergo addition reactions but ethane does not.

Functional Groups and the Homologous Series in Class 10 Science Chapter 4

The functional group decides the chemistry of a carbon compound. One or more hydrogen atoms in the chain are replaced by another atom or group, which gives the compound its specific properties, whatever the chain length.

A homologous series is a series of compounds with the same functional group, where each member differs from the next by a −CH₂− unit (mass 14 u). Methanol, ethanol, propanol and butanol all share the −OH group and have similar chemical properties; melting and boiling points rise along the series, but the chemistry stays the same.

For nomenclature, count the carbon atoms for the chain name, then add a prefix or suffix for the functional group. If the suffix begins with a vowel, the final "e" is dropped: a three-carbon ketone is propanone (likewise propanol, propanal, propanoic acid).

Chemical Properties of Carbon Compounds in Class 10 Science

Four reactions are tested almost every year: combustion, oxidation, addition and substitution, each with a standard balanced example.

Saturated hydrocarbons burn with a clean blue flame, unsaturated ones with a yellow, sooty flame. Oxidising agents like alkaline KMnO₄ convert ethanol to ethanoic acid. Addition hardens vegetable oils into vanaspati ghee with a nickel catalyst; substitution replaces methane's hydrogens with chlorine in sunlight.

Ethanol, Ethanoic Acid, Soaps and Detergents in Class 10 Science

Ethanol (CH₃CH₂OH) is a liquid alcohol and good solvent. Ethanoic acid (CH₃COOH), or acetic acid, is a weak carboxylic acid; a 5 to 8 percent solution is vinegar, and pure ethanoic acid is called glacial acetic acid.

Ethanoic acid plus an alcohol forms a sweet-smelling ester (esterification); the reverse with NaOH is saponification, used to make soap. Soaps are salts of long-chain carboxylic acids; each molecule has a water-loving ionic end and an oil-loving tail.

• Micelle formation: soap molecules cluster with tails toward the oily dirt and ionic heads out, forming a micelle that lifts the dirt away.
• Hard water problem: soap reacts with calcium and magnesium salts to form an insoluble scum, wasting soap.
• Detergents: do not form a scum, so they work even in hard water.

Other Resources for Class 10 Science Chapter 4 Carbon and its Compounds

Read the official NCERT Book chapter above, then revise with the matching NCERT Solutions, revision notes, formula sheet and handwritten notes. All resources for Class 10 Science Chapter 4 Carbon and its Compounds are linked in the table below.

NCERT Book for Class 10 Science: All Chapters

Related Links: Use the table below to open the official NCERT Book PDF for the other chapters of Class 10 Science. Every chapter ships with the same official textbook PDF, chapter overview, and board-ready FAQ.