MP Board Class 10 Science Chapter 4: Carbon and Its Compounds Notes 2027
🔬 MP Board Class 10 Science Chapter 4: Carbon and Its Compounds — Complete Notes 2027
Welcome to the complete revision notes for MP Board Class 10 Science Chapter 4: Carbon and Its Compounds. This chapter covers the unique properties of carbon, its allotropes, versatile bonding nature, homologous series, and important chemical reactions. These notes are prepared as per the latest MP Board 2026-27 syllabus with NCERT-based explanations and previous year questions.
📝 Chapter Overview
| Topic | Key Concepts |
|---|---|
| Bonding in Carbon | Covalent bonds, electron sharing, catenation |
| Allotropes of Carbon | Diamond, Graphite, Fullerenes, Buckyballs |
| Versatile Nature | Tetravalency, catenation, multiple bonds |
| Hydrocarbons | Saturated & Unsaturated, Alkanes, Alkenes, Alkynes |
| Functional Groups | Alcohol, Aldehyde, Ketone, Carboxylic Acid, Halides |
| Homologous Series | CH₂ increment, similar properties |
| Nomenclature | IUPAC naming rules |
| Chemical Reactions | Combustion, Oxidation, Addition, Substitution |
| Ethanol & Ethanoic Acid | Properties, reactions, uses |
| Soaps & Detergents | Micelle formation, cleansing action |
⚛️ 1. Bonding in Carbon — The Covalent Bond
Carbon has 4 valence electrons (atomic number 6, electronic configuration 2,4). It needs 4 more electrons to complete its octet. Instead of gaining or losing electrons (which would require high energy), carbon shares electrons to form covalent bonds.
- Covalent bond: A chemical bond formed by sharing of electrons between two atoms.
- Single bond: 1 shared pair (e.g., C—C in ethane)
- Double bond: 2 shared pairs (e.g., C=C in ethene)
- Triple bond: 3 shared pairs (e.g., C≡C in ethyne)
🔑 Key Properties of Covalent Compounds
- Low melting and boiling points
- Poor conductors of electricity (no free ions)
- Insoluble in water, soluble in organic solvents
- Generally liquids or gases at room temperature
💎 2. Allotropes of Carbon
Allotropes are different physical forms of the same element. Carbon has three main allotropes:
| Property | Diamond | Graphite | Fullerenes (C₆₀) |
|---|---|---|---|
| Structure | Tetrahedral (3D network) | Hexagonal layers (2D sheets) | Hollow cage (football-shaped) |
| Hybridization | sp³ | sp² | sp² |
| Hardness | Hardest natural substance | Soft, slippery | Moderate |
| Conductivity | Non-conductor | Good conductor | Semi-conductor |
| Uses | Cutting, jewellery, drilling | Pencil leads, lubricant, electrodes | Nanotechnology, medicine |
⚡ Important Fact: Diamond and graphite both are made of carbon atoms but diamond is the hardest mineral while graphite is soft and slippery because of different arrangements of carbon atoms.
🔗 3. Versatile Nature of Carbon
Carbon forms the largest number of compounds because of two properties:
- Catenation: The ability of carbon atoms to bond with other carbon atoms forming long chains, branched chains, and rings.
- Tetravalency: Carbon has 4 valence electrons, so it can form 4 covalent bonds with other atoms (C, H, O, N, S, halogens, etc.).
🧪 4. Hydrocarbons
Compounds containing only carbon (C) and hydrogen (H) are called hydrocarbons.
| Type | Bond Type | General Formula | Example |
|---|---|---|---|
| Alkane | Single (C—C) | CₙH₂ₙ₊₂ | CH₄ (Methane), C₂H₆ (Ethane) |
| Alkene | Double (C=C) | CₙH₂ₙ | C₂H₄ (Ethene), C₃H₆ (Propene) |
| Alkyne | Triple (C≡C) | CₙH₂ₙ₋₂ | C₂H₂ (Ethyne), C₃H₄ (Propyne) |
Saturated hydrocarbons: Alkanes (only single bonds)
Unsaturated hydrocarbons: Alkenes (double bonds) and Alkynes (triple bonds)
🏷️ 5. Functional Groups
A functional group is an atom or group of atoms that determines the chemical properties of a compound.
| Functional Group | Formula | Prefix/Suffix | Example |
|---|---|---|---|
| Alcohol | —OH | -ol | CH₃OH (Methanol) |
| Aldehyde | —CHO | -al | CH₃CHO (Ethanal) |
| Ketone | —CO— | -one | CH₃COCH₃ (Propanone/Acetone) |
| Carboxylic Acid | —COOH | -oic acid | CH₃COOH (Ethanoic acid) |
| Halo (Chloro/Bromo) | —Cl / —Br | Chloro-/Bromo- | CH₃Cl (Chloromethane) |
📊 6. Homologous Series
A homologous series is a group of organic compounds with the same functional group and same general formula, where each successive member differs by —CH₂— unit (14 atomic mass units).
Example — Alcohols (—OH):
| Name | Formula | Molecular Mass | Boiling Point (°C) |
|---|---|---|---|
| Methanol | CH₃OH | 32 | 64.7 |
| Ethanol | C₂H₅OH | 46 | 78.4 |
| Propanol | C₃H₇OH | 60 | 97.1 |
| Butanol | C₄H₉OH | 74 | 117.7 |
Characteristics of Homologous Series:
- Same functional group → similar chemical properties
- Gradual change in physical properties (MP, BP, solubility)
- Difference of CH₂ (14 u) between successive members
- Same general formula
📝 7. IUPAC Nomenclature Rules
- Identify the longest continuous carbon chain → parent chain
- Number the chain from the end nearest to the functional group / side chain
- Name the substituents (side chains) with prefixes and their positions
- Write name as: position-prefix + parent + suffix
Example: CH₃—CH₂—CH₂—OH → Propan-1-ol (or 1-Propanol)
🔥 8. Chemical Reactions of Carbon Compounds
A) Combustion Reaction
Carbon compounds burn in oxygen to produce CO₂, H₂O, heat, and light.
CH₄ + 2O₂ → CO₂ + 2H₂O + heat + light
⚠️ Incomplete combustion (limited oxygen) produces poisonous CO gas and soot (carbon).
B) Oxidation Reaction
Alcohols can be oxidized to carboxylic acids using oxidizing agents like alkaline KMnO₄ or acidified K₂Cr₂O₇.
CH₃CH₂OH + 2[O] →(alk. KMnO₄/Heat)→ CH₃COOH + H₂O
(Ethanol → Ethanoic acid)
C) Addition Reaction
Unsaturated hydrocarbons add hydrogen in the presence of catalysts (Ni/Pd/Pt) to become saturated.
C₂H₄ + H₂ →(Ni, 200°C)→ C₂H₆ (Ethene → Ethane)
This process is called hydrogenation — used to convert vegetable oils into vanaspati ghee.
D) Substitution Reaction
A hydrogen atom in a saturated hydrocarbon is replaced by another atom (usually halogen).
CH₄ + Cl₂ →(sunlight)→ CH₃Cl + HCl (Chloromethane)
🧴 9. Ethanol (C₂H₅OH) — Properties & Uses
| Property | Description |
|---|---|
| Physical State | Liquid (at room temp) |
| Odour | Characteristic alcoholic smell |
| Boiling Point | 78.4°C |
| Miscibility | Miscible with water in all proportions |
| Reaction with Na | 2Na + 2C₂H₅OH → 2C₂H₅ONa + H₂↑ |
| Reaction with Acid | C₂H₅OH + CH₃COOH →(Conc. H₂SO₄)→ CH₃COOC₂H₅ + H₂O (Esterification) |
| Dehydration | C₂H₅OH →(Hot Conc. H₂SO₄, 170°C)→ C₂H₄ + H₂O |
Uses: Antiseptic (70% solution), solvent in medicines and perfumes, alcoholic beverages, fuel (bioethanol).
🧪 10. Ethanoic Acid (CH₃COOH) — Properties & Reactions
| Property | Description |
|---|---|
| Common Name | Acetic acid (Vinegar = 5-8% acetic acid in water) |
| Physical State | Liquid, pungent smell |
| Boiling Point | 118°C |
| Acidic Nature | Turns blue litmus red (weak acid) |
| Reaction with NaHCO₃ | CH₃COOH + NaHCO₃ → CH₃COONa + CO₂↑ + H₂O |
| Esterification | CH₃COOH + C₂H₅OH →(Conc. H₂SO₄)→ CH₃COOC₂H₅ + H₂O |
| Saponification | CH₃COOC₂H₅ + NaOH → CH₃COONa + C₂H₅OH |
🫧 11. Soaps and Detergents
🧼 Soap Formation (Saponification)
Vegetable oil / fat + NaOH →(Heat)→ Soap + Glycerol
Soap molecules have two ends:
- Hydrophilic head (polar — ionic, —COO⁻Na⁺) — dissolves in water
- Hydrophobic tail (non-polar — long carbon chain) — dissolves in grease/oil
Micelle Formation
In water, soap molecules arrange in spherical structures called micelles, with hydrophobic tails pointing inward (trapping grease) and hydrophilic heads pointing outward (in water). This emulsifies grease, allowing it to be washed away.
Soap vs Detergent
| Feature | Soap | Detergent |
|---|---|---|
| Source | Natural (fats/oils) | Synthetic (petroleum by-products) |
| Hard water | Forms scum (insoluble Ca/Mg salts) — ineffective | Works well (soluble Ca/Mg salts) |
| Biodegradable | Yes | Some are non-biodegradable (cause pollution) |
📚 NCERT Solved Examples
Q1: Why does carbon form covalent bonds?
A: Carbon has 4 valence electrons. It cannot gain 4 electrons (C⁴⁻ is unstable) or lose 4 electrons (C⁴⁺ requires too much energy — 9950 kJ/mol). So carbon shares electrons to form covalent bonds, completing its octet.
Q2: What is the difference between saturated and unsaturated hydrocarbons?
A: Saturated hydrocarbons have only single C—C bonds (alkanes), while unsaturated have double (alkenes) or triple bonds (alkynes). Unsaturated compounds undergo addition reactions; saturated undergo substitution.
Q3: Why is ethanoic acid called a weak acid?
A: Ethanoic acid (CH₃COOH) partially dissociates in water to give H⁺ ions, unlike strong acids (HCl, H₂SO₄) which dissociate completely.
📖 Previous Year Questions (PYQs) — MP Board
1. (2024) Write the IUPAC name of CH₃—CH₂—CH₂—CHO.
Ans: Butanal
2. (2023) What is esterification? Give one example.
Ans: Reaction of carboxylic acid with alcohol in presence of conc. H₂SO₄ to form ester & water. E.g., CH₃COOH + C₂H₅OH → CH₃COOC₂H₅ + H₂O
3. (2023) Why does carbon form covalent bonds?
Ans: Carbon needs to gain or lose 4 electrons to complete its octet. This would require very high energy. So it shares electrons and forms covalent bonds.
4. (2022) What is a homologous series? Write its two characteristics.
Ans: A series of compounds with same functional group and general formula. Characteristics: (i) Same chemical properties, (ii) Difference of —CH₂— between successive members.
5. (2022) Explain the cleansing action of soap.
Ans: Soap molecules form micelles. The hydrophobic tail dissolves in grease/oil and the hydrophilic head remains in water. This emulsifies the grease, forming an emulsion which can be washed away.
⭐ Tips for MP Board Exams 2027
- Learn the naming of first 10 alkanes (methane to decane) thoroughly
- Practice writing structural formulas and IUPAC names
- Remember the difference between substitution and addition reactions
- Know the soap vs detergent comparison table
- Focus on ethanol and ethanoic acid reactions — these are high-weightage topics
- Practice at least 5 previous year questions from this chapter
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Keywords: Carbon and its Compounds Class 10 Notes, MP Board Science Chapter 4, Carbon covalent bonds, Allotropes of carbon diamond graphite fullerene, Hydrocarbons alkanes alkenes alkynes, Functional groups alcohol aldehyde ketone carboxylic acid, Homologous series, IUPAC nomenclature, Ethanol ethanoic acid properties, Soap micelle cleansing action, MP Board 2027 Science notes, NCERT Class 10 Carbon chapter