NCERT Solutions for Class 10 Science Chapter 4: Carbon and its Compounds
These Class 10 Science Chapter 4 solutions cover Carbon and its Compounds from the NCERT textbook (session 2026–27). You get every in-text “Questions” set and the complete end-of-chapter Exercises reproduced word-for-word and solved in clear, exam-ready steps — covalent bonding, the versatile nature of carbon, the homologous series, IUPAC nomenclature, chemical properties (combustion, oxidation, addition and substitution), the two important compounds ethanol and ethanoic acid, and the cleaning action of soaps and detergents.
Class: 10Subject: ScienceChapter: 4Topic: Carbon and its CompoundsBranch: ChemistrySession: 2026–27
Carbon is a remarkable element: although the earth’s crust has only about 0.02% carbon (as minerals like carbonates, coal and petroleum) and the atmosphere only about 0.03% carbon dioxide, carbon is the basis of all living things and of millions of compounds. This chapter explains why. Carbon, with four valence electrons, neither gains nor loses electrons; instead it shares them to form strong covalent bonds. Two special properties — tetravalency (a valency of four) and catenation (self-linking into chains, branches and rings) — allow carbon to build an enormous family of compounds. You then study saturated (single-bonded) and unsaturated (double/triple-bonded) hydrocarbons, structural isomers, functional groups, the homologous series and IUPAC nomenclature, and the chemical reactions of carbon compounds (combustion, oxidation, addition, substitution). Finally you learn the properties of ethanol and ethanoic acid and how soaps and detergents clean by forming micelles.
Key Concepts & Definitions
Covalent bond: a bond formed by the sharing of a pair of electrons between two atoms so that both attain a stable, completely filled (noble-gas) outermost shell. Sharing one pair gives a single bond, two pairs a double bond and three pairs a triple bond.
Catenation: the unique ability of carbon to form strong, stable bonds with other carbon atoms, giving long chains, branched chains and rings.
Tetravalency: carbon has a valency of four, so it can bond with up to four other atoms of carbon or other (monovalent) elements.
Hydrocarbons: compounds made of only carbon and hydrogen. Saturated hydrocarbons (only single C–C bonds) are alkanes; unsaturated ones are alkenes (C=C double bond) and alkynes (C≡C triple bond).
Structural isomers: compounds with the same molecular formula but different structures (different arrangement of atoms), e.g. the two forms of C4H10.
Functional group: a heteroatom or group of atoms that replaces hydrogen and gives the compound its characteristic chemical properties — e.g. –OH (alcohol), –CHO (aldehyde), >C=O (ketone), –COOH (carboxylic acid), –Cl/–Br (halo).
Homologous series: a family of compounds with the same functional group, in which successive members differ by a –CH2– unit (a mass difference of 14 u). Members have similar chemical properties but a gradual change in physical properties.
Oxidising agent: a substance that adds oxygen to (or removes hydrogen from) another substance, e.g. alkaline KMnO4 or acidified K2Cr2O7, which oxidise alcohols to carboxylic acids.
Esterification & saponification: an acid + an alcohol give a sweet-smelling ester (esterification); an ester + an alkali give back the alcohol and a sodium salt of the acid — the basis of soap making (saponification).
Micelle: a cluster of soap molecules in water in which the hydrophobic (oil-loving) tails point inward toward the oily dirt and the hydrophilic (water-loving) ionic ends point outward, allowing dirt to be lifted into water.
Formulae & General Rules
General formula — alkanes: CnH2n+2 (e.g. CH4, C2H6, C3H8).
General formula — alkenes: CnH2n (n = 2, 3, 4…; e.g. C2H4, C3H6).
General formula — alkynes: CnH2n−2 (e.g. C2H2, C3H4).
Homologous difference: successive members differ by –CH2–, a molecular-mass difference of 12 + 2(1) = 14 u.
Combustion (complete): hydrocarbon + O2 → CO2 + H2O + heat & light. E.g. CH4 + 2O2 → CO2 + 2H2O.
Naming with a vowel-starting suffix: drop the final ‘e’ of the chain name, then add the suffix (propane − e + one = propanone).
In-text “Questions” — Solutions
Questions (Page 61)
1. What would be the electron dot structure of carbon dioxide which has the formula CO2?
ANSWERIn CO2 the carbon atom forms two double bonds, one with each oxygen atom (O=C=O). Carbon shares two of its electrons with each oxygen, and each oxygen shares two of its electrons with carbon.Electron dot structure: each O=C bond is shown as two shared pairs (four dots) between the atoms; each oxygen also carries two lone pairs. In this way carbon completes its octet (8 shared electrons) and each oxygen completes its octet.Linear form: O::C::O, i.e. Ö = C = Ö (the double colons represent the two shared pairs of each double bond).
2. What would be the electron dot structure of a molecule of sulphur which is made up of eight atoms of sulphur? (Hint – The eight atoms of sulphur are joined together in the form of a ring.)
ANSWERSulphur (atomic number 16) has six valence electrons, so each sulphur atom needs two more electrons and forms two single covalent bonds with its two neighbours.The eight atoms therefore link in a closed ring (S8): each S is joined to the S on either side by one shared pair, and each S also has two lone pairs. Every atom thus completes its octet, giving a stable, puckered eight-membered ring — written as –S–S–S–S–S–S–S–S– closed into a cycle.
Questions (Page 68)
1. How many structural isomers can you draw for pentane?
ANSWERPentane (C5H12) has three structural isomers:(i) n-Pentane — a straight chain: CH3–CH2–CH2–CH2–CH3.(ii) Isopentane (2-methylbutane) — a four-carbon chain with a –CH3 branch on C-2: CH3–CH(CH3)–CH2–CH3.(iii) Neopentane (2,2-dimethylpropane) — a central carbon bonded to four –CH3 groups: C(CH3)4.
2. What are the two properties of carbon which lead to the huge number of carbon compounds we see around us?
ANSWER(i) Catenation — carbon forms strong, stable bonds with other carbon atoms, building long chains, branched chains and rings. This is shown to a far greater extent in carbon than in any other element.(ii) Tetravalency — carbon has a valency of four, so each carbon can bond with up to four other atoms (of carbon or of elements such as O, H, N, S, Cl), giving a vast variety of compounds.
3. What will be the formula and electron dot structure of cyclopentane?
ANSWERFormula: cyclopentane is a five-carbon saturated ring, so its molecular formula is C5H10 (as a ring it follows CnH2n).Electron dot structure: five carbon atoms are joined in a closed ring by single C–C bonds (one shared pair between each pair of adjacent carbons), and each carbon also bonds to two hydrogen atoms (each C–H is one shared pair). Every carbon thus has four shared pairs — two to its carbon neighbours and two to hydrogens — satisfying its tetravalency.
4. Draw the structures for the following compounds.
(i) Ethanoic acid (ii) Bromopentane* (iii) Butanone (iv) Hexanal.*Are structural isomers possible for bromopentane?
ANSWER(i) Ethanoic acid (CH3COOH): CH3–C(=O)–OH — a methyl group joined to a carboxylic acid (–COOH) group.(ii) Bromopentane (C5H11Br): e.g. 1-bromopentane CH3–CH2–CH2–CH2–CH2–Br. Yes, structural isomers are possible — the –Br can be placed on different carbons (1-, 2- and 3-bromopentane) and the carbon chain itself can be branched, giving several isomers.(iii) Butanone (CH3COCH2CH3): CH3–C(=O)–CH2–CH3 — a four-carbon chain with the ketone (>C=O) group on C-2.(iv) Hexanal (C5H11CHO): CH3–CH2–CH2–CH2–CH2–CHO — a six-carbon chain ending in the aldehyde (–CHO) group.
5. How would you name the following compounds?
(i) CH3—CH2—Br (ii) [a three-carbon chain ending in an aldehyde, –CHO] (iii) [a six-carbon chain with a triple bond, C≡C]
ANSWER(i) CH3–CH2–Br: a two-carbon chain (ethane) with a bromo group → Bromoethane.(ii) The structure shown is propanal — a three-carbon chain (propane) ending in an aldehyde (–al), CH3–CH2–CHO → Propanal.(iii) The structure shown is a six-carbon chain with a triple bond → Hexyne (a six-carbon alkyne, C6H10).(In the NCERT figures the second and third structures are drawn; the names follow from the number of carbons and the functional group/multiple bond shown.)
Questions (Page 71)
1. Why is the conversion of ethanol to ethanoic acid an oxidation reaction?
ANSWERWhen ethanol (CH3CH2OH) is converted to ethanoic acid (CH3COOH), oxygen is added to the molecule (and hydrogen is removed). Since the addition of oxygen / removal of hydrogen is the definition of oxidation, the conversion is an oxidation reaction.It is carried out using an oxidising agent such as alkaline potassium permanganate (KMnO4) or acidified potassium dichromate (K2Cr2O7), which supply the oxygen.
2. A mixture of oxygen and ethyne is burnt for welding. Can you tell why a mixture of ethyne and air is not used?
ANSWERWhen ethyne is burnt in pure oxygen, combustion is complete, producing a very hot, clean flame (the oxy-acetylene flame) hot enough to melt metals for welding.If ethyne were burnt in air (only about 21% oxygen), the limited oxygen would cause incomplete combustion, giving a sooty flame with much less heat. The lower temperature would not be enough for welding, so a mixture of ethyne and air is not used.
Questions (Page 74)
1. How would you distinguish experimentally between an alcohol and a carboxylic acid?
ANSWERUse the sodium carbonate / sodium hydrogencarbonate test. Add a little sodium hydrogencarbonate (or sodium carbonate) to each compound.The carboxylic acid reacts and gives a brisk effervescence of carbon dioxide gas (which turns lime-water milky): CH3COOH + NaHCO3 → CH3COONa + H2O + CO2.The alcohol gives no effervescence. (Litmus also helps: the carboxylic acid turns blue litmus red; the alcohol has no effect on litmus.)
2. What are oxidising agents?
ANSWEROxidising agents are substances that are capable of adding oxygen to (or removing hydrogen from) other substances. In doing so they oxidise the other substance.Examples: alkaline potassium permanganate (KMnO4) and acidified potassium dichromate (K2Cr2O7), which oxidise alcohols to carboxylic acids.
Questions (Page 76)
1. Would you be able to check if water is hard by using a detergent?
ANSWERNo. Detergents do not form an insoluble scum with the calcium and magnesium ions present in hard water — their charged ends remain soluble. So a detergent lathers well in both soft and hard water and shows no difference.Therefore a detergent cannot be used to tell hard water from soft water. A soap should be used instead, because soap forms a curdy white scum (less lather) in hard water and a good lather in soft water.
2. People use a variety of methods to wash clothes. Usually after adding the soap, they ‘beat’ the clothes on a stone, or beat it with a paddle, scrub with a brush or the mixture is agitated in a washing machine. Why is agitation necessary to get clean clothes?
ANSWERSoap molecules trap the oily dirt inside micelles, but most dirt clings to the cloth fibres. Agitation (beating, scrubbing or churning) supplies the mechanical energy needed to loosen and dislodge the trapped dirt particles from the cloth.Once freed, the dirt is held in the centre of the micelles and is carried away into the water. Hence agitation is necessary to get the clothes clean.
End-of-Chapter Exercises — Solutions
1. Ethane, with the molecular formula C2H6 has
(a) 6 covalent bonds. (b) 7 covalent bonds. (c) 8 covalent bonds. (d) 9 covalent bonds.
ANSWER(b) 7 covalent bonds.In C2H6 there is one C–C bond and six C–H bonds (each carbon is joined to three hydrogens). Total = 1 + 6 = 7 covalent bonds.
2. Butanone is a four-carbon compound with the functional group
(a) carboxylic acid. (b) aldehyde. (c) ketone. (d) alcohol.
ANSWER(c) ketone.The suffix ‘-one’ indicates the ketone (>C=O) group. Butanone is CH3–CO–CH2–CH3.
3. While cooking, if the bottom of the vessel is getting blackened on the outside, it means that
(a) the food is not cooked completely. (b) the fuel is not burning completely. (c) the fuel is wet. (d) the fuel is burning completely.
ANSWER(b) the fuel is not burning completely.A black deposit (soot/carbon) means incomplete combustion, usually because the air holes are blocked and the oxygen supply is insufficient.
4. Explain the nature of the covalent bond using the bond formation in CH3Cl.
ANSWERIn chloromethane (CH3Cl), carbon (4 valence electrons) shares electrons to complete its octet, hydrogen (1 electron) completes its duplet, and chlorine (7 valence electrons) completes its octet — all by sharing, not by transfer of electrons.Carbon forms three C–H single bonds (carbon shares one electron with each of three hydrogens) and one C–Cl single bond (carbon and chlorine share one pair of electrons).Thus all four valencies of carbon are satisfied by four single covalent bonds. Because electrons are only shared (no ions form), CH3Cl is a covalent compound with a low melting/boiling point and poor electrical conductivity.
5. Draw the electron dot structures for
(a) ethanoic acid. (b) H2S. (c) propanone. (d) F2.
ANSWER(a) Ethanoic acid (CH3COOH): the CH3 carbon shares one pair with each of three H atoms; it is single-bonded to the second carbon; that carbon is double-bonded to one O (two shared pairs) and single-bonded to an –O–H group. The carbonyl O has two lone pairs and the hydroxyl O has two lone pairs.(b) H2S: sulphur (6 valence electrons) shares one electron with each of two hydrogens, forming two S–H single bonds; sulphur is left with two lone pairs (bent shape, like water).(c) Propanone (CH3COCH3): two CH3 groups (each carbon shares one pair with three H atoms) are joined to a central carbon, which is double-bonded to oxygen (two shared pairs); the oxygen carries two lone pairs.(d) F2: each fluorine (7 valence electrons) shares one pair of electrons with the other, forming a single F–F bond; each fluorine also has three lone pairs, completing both octets.
6. What is an homologous series? Explain with an example.
ANSWERA homologous series is a family of organic compounds having the same functional group, in which successive members differ by a –CH2– unit (a molecular-mass difference of 14 u). All members can be written by one general formula.Members show similar chemical properties (decided by the functional group) but a gradual change in physical properties (melting point, boiling point, solubility) as the molecular mass increases.Example — alkanes (general formula CnH2n+2): methane CH4, ethane C2H6, propane C3H8, butane C4H10 — each differs from the next by –CH2–. (Another example: the alcohols CH3OH, C2H5OH, C3H7OH…)
7. How can ethanol and ethanoic acid be differentiated on the basis of their physical and chemical properties?
ANSWERThey can be told apart as follows:
Basis
Ethanol (CH3CH2OH)
Ethanoic acid (CH3COOH)
Smell
Pleasant smell
Smell of vinegar (sharp, sour)
Melting point
156 K (does not freeze in ordinary cold)
290 K — freezes in cold climates (“glacial” acetic acid)
Litmus test
No effect on litmus (neutral)
Turns blue litmus red (acidic)
Sodium carbonate / hydrogencarbonate
No reaction, no effervescence
Brisk effervescence of CO2 (turns lime-water milky)
Reaction with sodium hydroxide
Does not react
Reacts to form sodium ethanoate + water
The simplest single test is the sodium hydrogencarbonate test: ethanoic acid gives brisk effervescence of CO2; ethanol does not.
8. Why does micelle formation take place when soap is added to water? Will a micelle be formed in other solvents such as ethanol also?
ANSWERA soap molecule has two ends: a hydrophilic (water-loving) ionic end and a long hydrophobic (water-hating, oil-loving) hydrocarbon tail. In water, the hydrocarbon tails cannot dissolve, so the molecules arrange themselves into a cluster — a micelle — with the tails pointing inward (toward the oily dirt) and the ionic heads facing outward into the water. This keeps the tails away from water and lets soap clean.No, a micelle will not form in a solvent such as ethanol (a hydrocarbon-like solvent). The hydrocarbon tails are soluble in such solvents, so there is no need for the molecules to hide their tails — hence no micelles form.
9. Why are carbon and its compounds used as fuels for most applications?
ANSWERCarbon and most of its compounds burn (combust) readily in air, releasing a large amount of heat and light. They have a high calorific value, so they give a lot of energy for a given mass.They generally burn without leaving much residue, are easily available (coal, petroleum, natural gas, wood) and convenient to store and transport. For these reasons carbon and its compounds are used as fuels for most applications.
10. Explain the formation of scum when hard water is treated with soap.
ANSWERHard water contains dissolved calcium and magnesium salts. When soap (a sodium salt of a long-chain carboxylic acid) is added, these Ca2+ and Mg2+ ions react with the soap to form insoluble calcium and magnesium salts of the fatty acid.This insoluble, sticky white substance is called scum. Because part of the soap is wasted in forming scum, a much larger amount of soap is needed to get a lather in hard water.
11. What change will you observe if you test soap with litmus paper (red and blue)?
ANSWERSoap is basic (alkaline) in nature because it is the salt of a strong base (NaOH) and a weak acid (a fatty acid).Therefore soap turns red litmus blue, while blue litmus shows no change (it stays blue). This confirms its basic nature.
12. What is hydrogenation? What is its industrial application?
ANSWERHydrogenation is the addition reaction in which unsaturated hydrocarbons add hydrogen in the presence of a catalyst (nickel or palladium) to give saturated hydrocarbons. It is a type of addition reaction.Industrial application: it is used in the hydrogenation of vegetable oils. Vegetable oils (unsaturated) are converted into solid fats such as vanaspati ghee using a nickel catalyst — turning ‘healthy’ unsaturated oils into semi-solid saturated fats.
13. Which of the following hydrocarbons undergo addition reactions:
C2H6, C3H8, C3H6, C2H2 and CH4.
ANSWEROnly unsaturated hydrocarbons (those with double or triple bonds) undergo addition reactions.C3H6 (propene, contains a C=C double bond) and C2H2 (ethyne, contains a C≡C triple bond) undergo addition reactions.C2H6, C3H8 and CH4 are saturated (only single bonds), so they do not undergo addition reactions.
14. Give a test that can be used to differentiate between saturated and unsaturated hydrocarbons.
ANSWERBromine-water test: add a few drops of orange-red bromine water to each hydrocarbon.An unsaturated hydrocarbon adds bromine across its double/triple bond and decolourises the bromine water. A saturated hydrocarbon does not react and the bromine water stays orange-red.(Alternatively, on burning, saturated hydrocarbons give a clean blue flame while unsaturated hydrocarbons give a yellow, sooty flame.)
15. Explain the mechanism of the cleaning action of soaps.
ANSWERA soap molecule has a hydrophobic (oil-loving) hydrocarbon tail and a hydrophilic (water-loving) ionic head. Most dirt is oily.When soap is added to water, the tails attach to the oily dirt while the ionic heads stay in the water, forming clusters called micelles with the oily dirt trapped in the centre and the ionic heads on the outside.This breaks the dirt into tiny droplets (an emulsion) suspended in water. With agitation, the trapped dirt is lifted off the cloth; the micelles stay dispersed (they repel one another) and are rinsed away with water, leaving the cloth clean.
Extra Practice Questions
Short Answer Type Questions
Q1. Why do carbon compounds have low melting and boiling points?
ANSWERCarbon compounds are covalent. The bonds within the molecule are strong, but the intermolecular forces between molecules are weak. Little energy is needed to separate the molecules, so the melting and boiling points are low.
Q2. Why are covalent compounds generally poor conductors of electricity?
ANSWERIn covalent compounds electrons are shared, so no charged particles (ions or free electrons) are produced. With no mobile charge carriers, these compounds cannot conduct electricity.
Q3. Name the two allotropes of carbon mentioned in the chapter and give one property of each.
ANSWERDiamond — each carbon is bonded to four others in a rigid 3-D structure; it is the hardest known substance. Graphite — each carbon is bonded to three others in flat hexagonal layers; it is soft, slippery and a good conductor of electricity. (A third class is the fullerenes, e.g. C-60.)
Q4. What is denatured alcohol? Why is alcohol denatured?
ANSWERDenatured alcohol is industrial ethanol made unfit for drinking by adding poisonous substances such as methanol (and blue dye to identify it). Alcohol is denatured to prevent the misuse of industrial ethanol as a drink and to allow it to be sold tax-free for industrial use.
Q5. Write the reaction of ethanoic acid with sodium hydrogencarbonate and name the gas produced.
ANSWERCH3COOH + NaHCO3 → CH3COONa + H2O + CO2. The gas produced is carbon dioxide (CO2), which turns lime-water milky.
Long Answer Type Questions
Q1. Describe the reactions of ethanol with (a) sodium and (b) hot concentrated sulphuric acid, with equations.
ANSWER(a) Reaction with sodium: ethanol reacts with sodium metal to evolve hydrogen gas, the other product being sodium ethoxide: 2Na + 2CH3CH2OH → 2CH3CH2O–Na+ + H2. This shows the slightly acidic nature of the –OH hydrogen.(b) Dehydration: on heating ethanol at 443 K with excess concentrated sulphuric acid, water is removed and the unsaturated hydrocarbon ethene is formed: CH3CH2OH → (hot conc. H2SO4) → CH2=CH2 + H2O. Here concentrated H2SO4 acts as a dehydrating agent.
Q2. What is esterification? What is saponification? Write the equations involved.
ANSWEREsterification: a carboxylic acid reacts with an alcohol in the presence of a little concentrated sulphuric acid (acid catalyst) to give a sweet-smelling ester and water: CH3COOH + C2H5OH → CH3COOC2H5 + H2O. Esters are used in perfumes and as flavouring agents.Saponification: on heating with an alkali (NaOH), the ester is hydrolysed back to the alcohol and the sodium salt of the carboxylic acid (a soap): CH3COOC2H5 + NaOH → C2H5OH + CH3COONa. This reaction is used to make soap.
Q3. Explain combustion, oxidation, addition and substitution reactions of carbon compounds with one example each.
ANSWERCombustion: carbon compounds burn in oxygen to give CO2, water, heat and light, e.g. CH4 + 2O2 → CO2 + 2H2O + heat & light.Oxidation: alcohols are oxidised to carboxylic acids by oxidising agents, e.g. ethanol → (alkaline KMnO4) → ethanoic acid.Addition: unsaturated hydrocarbons add hydrogen over a Ni/Pd catalyst, e.g. vegetable oil + H2 → (Ni) → vanaspati (saturated fat).Substitution: in sunlight, chlorine replaces hydrogen of saturated hydrocarbons one by one, e.g. CH4 + Cl2 → (sunlight) → CH3Cl + HCl.
For each Assertion–Reason question, choose: (A) Both true and the Reason correctly explains the Assertion; (B) Both true but the Reason is not the correct explanation; (C) Assertion true, Reason false; (D) Assertion false, Reason true.
A-R 1. Assertion: Carbon forms covalent bonds rather than ionic bonds.
Reason: Gaining or losing four electrons would require carbon’s small nucleus to hold an unstable charge, so it shares electrons instead.
A-R 2. Assertion: Unsaturated hydrocarbons are more reactive than saturated hydrocarbons.
Reason: Unsaturated hydrocarbons contain double or triple bonds that can take part in addition reactions.
A-R 3. Assertion: Detergents can be used to check whether water is hard.
Reason: Detergents form an insoluble scum with calcium and magnesium ions of hard water.
A-R 4. Assertion: Soap is not effective for cleaning in hard water.
Reason: Soap reacts with calcium and magnesium salts in hard water to form an insoluble scum.
A-R 5. Assertion: The conversion of ethanol to ethanoic acid is an oxidation reaction.
Reason: Oxygen is added to ethanol using an oxidising agent such as alkaline KMnO4.
Answer key: 1-(A), 2-(A), 3-(D), 4-(A), 5-(A).
Common Mistakes & Exam Tips
Common mistakes to avoid
Counting only the C–H bonds and forgetting the C–C bond(s) when totalling covalent bonds (ethane has 7, not 6).
Mixing up the general formulae — alkanes CnH2n+2, alkenes CnH2n, alkynes CnH2n−2.
Forgetting to drop the final ‘e’ before a vowel-starting suffix (propane → propanone, not propaneone).
Saying a detergent can detect hard water — it cannot; only soap forms scum.
Writing that micelles form in ethanol — they do not, because the tails dissolve in such solvents.
Forgetting the conditions on equations (e.g. 443 K + conc. H2SO4 for dehydration; sunlight for substitution; Ni catalyst for hydrogenation).
Always write balanced equations with their conditions (temperature, catalyst, sunlight) — examiners give separate marks for the condition. When asked to “differentiate”, give a clear chemical test plus the observation (e.g. sodium hydrogencarbonate → brisk effervescence for the acid; bromine water decolourised for unsaturated). For electron-dot questions, count valence electrons first, then show shared pairs and lone pairs. Learn the four named reactions (combustion, oxidation, addition, substitution) with one example each, and remember the two key properties of carbon — tetravalency and catenation.
Frequently Asked Questions
What is Class 10 Science Chapter 4 about?
Chapter 4, Carbon and its Compounds, explains covalent bonding in carbon, why carbon forms millions of compounds (tetravalency and catenation), saturated and unsaturated hydrocarbons, structural isomers, functional groups, the homologous series and IUPAC nomenclature, chemical reactions (combustion, oxidation, addition, substitution), the properties of ethanol and ethanoic acid, and how soaps and detergents clean.
What are the two properties of carbon responsible for so many carbon compounds?
Catenation (carbon’s ability to form strong bonds with other carbon atoms, making chains, branches and rings) and tetravalency (a valency of four, so each carbon can bond with up to four other atoms).
How are ethanol and ethanoic acid distinguished?
Add sodium hydrogencarbonate: ethanoic acid gives brisk effervescence of carbon dioxide (which turns lime-water milky), while ethanol gives no reaction. Ethanoic acid also turns blue litmus red; ethanol is neutral.
Are these Class 10 Science Chapter 4 solutions free?
Yes. All solutions are free and follow the official NCERT Science textbook for session 2026–27, with every in-text and exercise question solved step by step.
