Class 10 Science Chapter 4: Carbon and Its Compounds – NCERT Solutions Notes Carbon and Its Compounds is an important chapter in Class 10 Science that explains the nature of carbon, its bonding, hydrocarbons, and important organic compounds. It is one of the most scoring chapters if concepts are clear. These notes are designed for quick revision and exam preparation. Key Concepts Carbon Carbon is a non-metal that forms a large number of compounds due to its unique property of catenation (forming chains) and tetravalency (forms 4 bonds). Tetravalency Carbon has 4 valence electrons, so it forms 4 covalent bonds with other atoms. Covalent Bond A bond formed by sharing of electrons between atoms. Example: H₂, O₂, CH₄ Types of Carbon Compounds 1. Saturated Hydrocarbons (Alkanes) Contain single bonds only. Example: CH₄ (Methane), C₂H₆ (Ethane) 2. Unsaturated Hydrocarbons Contain double or triple bonds. Alkenes: C₂H₄ Alkynes: C₂H₂ Homologous Series A series of compounds with similar chemical properties and a difference of CH₂ group. Functional Groups Atoms or groups of atoms that give specific properties to compounds. Alcohol: –OH Aldehyde: –CHO Ketone: >C=O Carboxylic acid: –COOH Nomenclature (IUPAC Rules) Steps to name organic compounds: Identify longest carbon chain Identify functional group Number the chain Write name with prefixes and suffixes Chemical Properties of Carbon Compounds 1. Combustion Carbon compounds burn in oxygen to produce CO₂ and H₂O. Example: CH₄ + O₂ → CO₂ + H₂O + heat 2. Oxidation Carbon compounds react with oxygen to form oxidized products. 3. Addition Reaction Unsaturated compounds add hydrogen in presence of catalyst. Example: C₂H₄ + H₂ → C₂H₆ 4. Substitution Reaction One atom replaces another in saturated hydrocarbons. Example: CH₄ + Cl₂ → CH₃Cl + HCl Ethanol and Ethanoic Acid Ethanol (C₂H₅OH) Used in alcoholic drinks and solvents Burns cleanly Ethanoic Acid (CH₃COOH) Known as acetic acid Used in vinegar Soaps and Detergents Soap Made from fats and oils; reacts with hard water poorly. Detergent Synthetic cleaning agents effective in hard water. Micelles Formation Soap molecules form micelles that trap dirt and grease. NCERT Important Questions (Concept Based) Why does carbon form large number of compounds? Due to catenation and tetravalency. What is homologous series? A series differing by CH₂ group with similar properties. Why do soaps not work well in hard water? Because they form insoluble salts with calcium and magnesium. Important Reactions to Remember CH₄ + 2O₂ → CO₂ + 2H₂O C₂H₄ + H₂ → C₂H₆ CH₄ + Cl₂ → CH₃Cl + HCl Why this chapter is important This chapter is highly scoring and concept-based. It is frequently asked in exams in: Organic reactions Functional groups Naming compounds NCERT reasoning questions Final Revision Tip Focus on: Functional groups Reaction types IUPAC naming Difference between soap and detergent