CBSE Class 10 Science Question 11 of 15

Carbon and its Compounds — Question 15

Back to all questions
15
Question

Question 15

Explain the mechanism of the cleaning action of soaps.

Answer

Most dirt is oily in nature and oil does not dissolve in water. The molecules of soap are sodium or potassium salts of long-chain carboxylic acids. The ionic-end of soap interacts with water while the carbon chain interacts with oil. The soap molecules, thus form structures called micelles where one end of the molecule is towards the oil droplet while the ionic end faces outside. This forms an emulsion in water. The soap micelle thus helps in pulling out the dirt in water and we can wash our clothes clean.

Web Content: Carbon and Its Compounds | Bright Tutorials
BRIGHT TUTORIALS
Bright Tutorials Logo
BRIGHT TUTORIALS
CBSE Class X | Academic Year 2026-2027
9403781999
Excellence in Education
Science | Chapter 4: Carbon and Its CompoundsWeb Content

Chapter 4: Carbon and Its Compounds — Quick Revision Guide

Introduction

Carbon is unique in its ability to form millions of compounds due to catenation and tetravalency. This chapter covers covalent bonding, hydrocarbons, homologous series, IUPAC nomenclature, and important carbon compounds.

Key Points at a Glance

  1. Carbon (2,4) forms 4 covalent bonds (sharing electrons) due to tetravalency
  2. Catenation: carbon-carbon bonding in chains, branches, and rings; allotropes: diamond, graphite, fullerene
  3. Hydrocarbons: alkanes (CnH2n+2, single), alkenes (CnH2n, double), alkynes (CnH2n−2, triple)
  4. Homologous series: same general formula, differ by CH2, similar chemical properties, gradation in physical properties
  5. IUPAC naming: root (meth/eth/prop/but) + suffix (-ane/-ene/-yne) + functional group suffix (-ol/-al/-one/-oic acid)
  6. Combustion: hydrocarbons + O2 → CO2 + H2O; saturated = clean flame, unsaturated = sooty
  7. Oxidation: alcohols → aldehydes/acids (alk. KMnO4); Addition: unsaturated + H2 → saturated (Ni catalyst); Substitution: saturated + Cl2 → chlorinated (sunlight)
  8. Ethanol: fermentation of sugars; dehydration gives ethene; methanol is lethal
  9. Ethanoic acid (vinegar): reacts with carbonates, alcohols (esterification: produces fruity-smelling ester)
  10. Soap vs detergent: soap fails in hard water (scum); detergent works; both clean via micelle formation

Real-World Connections

LPG and CNG are hydrocarbon fuels; synthetic polymers (plastic, nylon) are carbon compounds; vanaspati ghee is made by hydrogenation; soaps and detergents for cleaning; alcohol in sanitisers.

Quick Self-Test (5 Questions)

  1. What is the most important concept you learned from this chapter?
  2. Can you write three key equations/formulae from this chapter from memory?
  3. Draw a labelled diagram relevant to this chapter without looking at your notes.
  4. Explain one real-world application of a concept from this chapter.
  5. What is one common mistake students make in this chapter, and how can you avoid it?

Further Study

  • NCERT Textbook Chapter 4
  • NCERT Exemplar Problems
  • Bright Tutorials Detailed Notes: ch04-carbon-compounds.html
  • Bright Tutorials Practice Questions: ch04-carbon-compounds.html
  • Previous Year CBSE Board Papers

Bright Tutorials | Hariom Nagar, Nashik Road | 9403781999 | brighttutorials.in