Chapter 4: Carbon and its Compounds
Simple, exam-focused CBSE Class 10 Science notes — star topics, concepts, common mistakes, and previous year question patterns, all on one page.
Chapter 4: Carbon and its Compounds
⭐ Star Topics / Most Important
- Tetravalency and catenation of carbon
- Homologous series
- Nomenclature of organic compounds
- Soaps and detergents (micelle formation)
Detailed Chapter Notes
Carbon (atomic number 6) has 4 valence electrons, so it prefers covalent bonding rather than gaining/losing 4 electrons.
Catenation is carbon's ability to form long chains, branches, and rings by bonding with other carbon atoms — the reason millions of carbon compounds exist.
Homologous series is a family with the same general formula, differing by a -CH2 unit each time. Alkanes (CnH2n+2), alkenes (CnH2n), alkynes (CnH2n-2).
Functional groups decide chemical behaviour: -OH (alcohol), -CHO (aldehyde), -COOH (carboxylic acid), -CO- (ketone). Ethanol and ethanoic acid (in vinegar) are the star compounds for boards.
Key reactions: combustion (saturated hydrocarbons burn with a clean blue flame, unsaturated with a sooty yellow flame), oxidation (alcohol → carboxylic acid via alkaline KMnO4), addition (unsaturated + H2 with a nickel catalyst — how vegetable oil becomes ghee), substitution (saturated hydrocarbons + chlorine in sunlight).
Soaps have a hydrophilic head and hydrophobic tail. In water they form micelles, trapping oil/dirt in the centre while the outer surface stays in contact with water, so the whole thing rinses away.
Students frequently mix up alkene vs alkyne general formulas — alkenes have one double bond (CnH2n), alkynes have one triple bond (CnH2n-2). Also, ethanoic acid is a weak acid, not a strong one — this distinction is often specifically tested.
Search on YouTube: Carbon and its Compounds Class 10 full chapter animation for a visual walkthrough of this chapter.
- Why does carbon form covalent bonds instead of ionic bonds? (2 marks)
- Draw the electron dot structure of methane (2 marks)
- What happens when ethanol reacts with ethanoic acid in presence of concentrated sulphuric acid? Name the reaction (3 marks)
- Why are soaps not effective in hard water while detergents are? (3 marks, HOTS)
- Differentiate between saturated and unsaturated hydrocarbons with examples (2 marks)