Latest Updates
Download Now : Previous Year Question Paper Class 10
Practice now : Sample Paper Class 10 CBSE 2025-26
Prepare Now : Class 10 Syllabus 2025-26
Prepare Now : Important Question for Class 10
NCERT Solutions for Class 10 Science Chapter 4 – Carbon and Its Compounds
Chapter 4, “Carbon and Its Compounds,” is an important topic in Class 10 Science, and understanding it will help you grasp the basics of Organic Chemistry. Carbon is a special element that is the foundation of all living things on Earth. In this chapter, you’ll learn about the different carbon compounds, their properties, and their uses.
Bookflicker’s NCERT Solutions for Class 10 Science Chapter 4 provide detailed answers to all the questions, making learning easier. These solutions are designed to help you understand difficult concepts and improve your problem-solving skills with step-by-step explanations.
Class 10 Carbon and Its Compounds solutions, created by Bookflicker experts and updated according to the latest CBSE syllabus. Start using Bookflicker to aim for academic success!
Table of Contents
Quick overview for NCERT Solutions for Carbon and Its Compounds for Class 10
- Using the Class 10 Carbon and Its Compounds resources helps students evaluate their preparation.
- It aids in strengthening their understanding of Organic Chemistry.
- The materials provide a solid foundation for learning about carbon compounds.
- It helps students get familiar with key concepts like hydrocarbons, bonds, and chemical reactions.
- Students can improve their knowledge through practice questions and answers.
- Students will learn how soap and detergents work to remove dirt from clothes.
- By using the Class 10 Carbon and Its Compounds study materials, students can gauge their preparation level and build a solid foundation in Organic Chemistry.
NCERT Solutions for Chapter 4 Science Class 10 Carbon And Its Compounds
Intext Exercise
Question 1: What would be the electron dot structure of carbon dioxide which has the formula CO2?
Answer: Electron dot structure of CO2 is
Question 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.)
Answer: Electron dot structure of a sulphur molecule
Question 3: How many structural isomers can you draw for pentane?
Answer: Three structural isomers are possible for pentane.
Question 4: What are the two properties of carbon which lead to the huge number of carbon compounds we see around us?
Answer: The two features of carbon that give rise to a large number of compounds are as follows:
(i) Catenation − It is the ability to form bonds with other atoms of carbon.
(ii) Tetravalency − With the valency of four, carbon is capable of bonding with four other atoms.
Question 5: What will be the formula and electron dot structure of cyclopentane?
Answer: The formula for cyclopentane is C5H10. Its electron dot structure is given below.
Question 6: Draw the structures for the following compounds.
(i) Ethanoic acid (ii) Bromopentane*
(iii) Butanone (iv) Hexanal
*Are structural isomers possible for bromopentane?
Answer:
(ii) There are many structural isomers possible for bromopentane. Among them, the structures of three isomers are given.
Question 7: Why do ionic compounds have high melting points?
Answer: Ionic compounds have strong electrostatic forces of attraction between the ions. Therefore, it requires a lot of energy to overcome these forces. That is why ionic compounds have high melting points.
Question 8: Why is the conversion of ethanol to ethanoic acid an oxidation reaction?
Answer:
Since the conversion of ethanol to ethanoic acid involves the addition of oxygen to ethanol, it is an oxidation reaction.
Question 9: A mixture of oxygen and ethyne is burnt for welding. Can you tell why a mixture of ethyne and air is not used?
Answer:
When ethyne is burnt in air, it gives a sooty flame. This is due to incomplete combustion caused by limited supply of air. However, if ethyne is burnt with oxygen, it gives a clean flame with temperature 3000°C because of complete combustion. This oxy-acetylene flame is used for welding. It is not possible to attain such a high temperature without mixing oxygen. This is the reason why a mixture of ethyne and air is not used.
Question 10: How would you distinguish experimentally between an alcohol and a carboxylic acid?
Answer: We can distinguish between an alcohol and a carboxylic acid on the basis of their reaction with carbonates and hydrogen carbonates. Acid reacts with carbonate and hydrogen carbonate to evolve CO2 gas that turns lime water milky.
Alcohols, on the other hand, do not react with carbonates and hydrogen carbonates.
Question 11: What are oxidising agents?
Answer: Some substances such as alkaline potassium permanganate and acidified potassium dichromate are capable of adding oxygen to others. These are known as oxidising agents.
Question 12: Would you be able to check if water is hard by using a detergent?
Answer: Detergents are ammonium or sulphonate salts of long chain carboxylic acids. Unlike soap, they do not react with calcium and magnesium ions present in hard water to form scum. They give a good amount of lather irrespective of whether the water is hard or soft. This means that detergents can be used in both soft and hard water. Therefore, it cannot be used to check whether the water is hard or not.
Question 13: 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?
Answer: A soap molecule has two parts namely hydrophobic and hydrophilic. With the help of these, it attaches to the grease or dirt particle and forms a cluster called micelle. These micelles remain suspended as a colloid. To remove these micelles (entrapping the dirt), it is necessary to agitate clothes.
Question 14: 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) Ethane has 7 covalent bonds.
Question 15: Butanone is a four-carbon compound with the functional group
(a) carboxylic acid.
(b) aldehyde acid.
(c) ketone.
(d) alcohol.
Answer: (c) The functional group of butanone is ketone.
Question 16: 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) While cooking, if the bottom of the vessel is getting blackened on the outside, then it means that the fuel is not burning completely.
Question 17: Explain the nature of the covalent bond using the bond formation in CH3Cl.
Answer: Carbon can neither lose four of its electrons nor gain four electrons as both the processes require extra amount of energy and would make the system unstable. Therefore, it completes its octet by sharing its four electrons with other carbon atoms or with atoms of other elements. The bonds that are formed by sharing electrons are known as covalent bonds. In covalent bonding, both the atoms share the valence electrons, i.e., the shared electrons belong to the valence shells of both the atoms.
Here, carbon requires 4 electrons to complete its octet, while each hydrogen atom requires one electron to complete its duplet. Also, chlorine requires an electron to complete the octet. Therefore, all of these share the electrons and as a result, carbon forms 3 bonds with hydrogen and one with chlorine.
Question 18: Draw the electron dot structures for
(a) ethanoic acid.
(b) H2S.
(c) propanone.
(d) F2.
Answer:
Question 19: What is a homologous series? Explain with an example.
Answer: A homologous series is a series of carbon compounds that have different numbers of carbon atoms but contain the same functional group.
For example, methane, ethane, propane, butane, etc. are all part of the alkane homologous series. The general formula of this series is CnH2n+2.
Methane CH4
Ethane CH3CH3
Propane CH3CH2CH3
Butane CH3CH2CH2CH3
It can be noticed that there is a difference of −CH2 unit between each successive compound.
Question 20: How can ethanol and ethanoic acid be differentiated on the basis of their physical and chemical properties?
Answer:
- Ethanol is a liquid at room temperature with a pleasant odour while ethanoic acid has vinegar-like smell. The melting point of ethanoic acid is 17°C. This is below room temperature and hence, it freezes during winters.
- Ethanoic acid reacts with metal carbonates and metal hydrogencarbonates to form salt, water, and carbon dioxide gas while ethanol does not react with them.
Question 21: In the electrolytic refining of a metal M, what would you take as the anode, the cathode and the electrolyte?
Answer: In the electrolytic refining of a metal M:
Anode → Impure metal M
Cathode → Thin strip of pure metal M
Electrolyte → Solution of salt of the metal M
Question 22: Why are carbon and its compounds used as fuels for most applications?
Answer: Most of the carbon compounds give a lot of heat and light when burnt in air. Saturated hydrocarbons burn with a clean flame and no smoke is produced. The carbon compounds, used as a fuel, have high calorific values. Therefore, carbon and its compounds are used as fuels for most applications.
Question 23: Explain the formation of scum when hard water is treated with soap.
Answer: Soap does not work properly when the water is hard. A soap is a sodium or potassium salt of long chain fatty acids. Hard water contains salts of calcium and magnesium. When soap is added to hard water, calcium and magnesium ions present in water displace sodium or potassium ions from the soap molecules forming an insoluble substance called scum. A lot of soap is wasted in the process.
Question 24: What change will you observe if you test soap with litmus paper (red and blue)?
Answer: Since soap is basic in nature, it will turn red litmus blue. However, the colour of blue litmus will remain blue.
Question 25: What is hydrogenation? What is its industrial application?
Answer: Hydrogenation is the process of addition of hydrogen. Unsaturated hydrocarbons are added with hydrogen in the presence of palladium and nickel catalysts to give saturated hydrocarbons.
This reaction is applied in the hydrogenation of vegetables oils, which contain long chains of unsaturated carbons.
Question 26: Which of the following hydrocarbons undergo addition reactions: C2H6, C3H8, C3H6, C2H2 and CH4.
Answer: Unsaturated hydrocarbons undergo addition reactions. Being unsaturated hydrocarbons, C3H6 and C2H2 undergo addition reactions.
Question 27: Give a test that can be used to differentiate chemically between butter and cooking oil.
Answer: Butter contains saturated fats. Therefore, it cannot be hydrogenated. On the other hand, oil has unsaturated fats. That is why it can be hydrogenated to saturated fats (solids).
Question 28: Explain the mechanism of the cleaning action of soaps.
Answer: Cleansing action of soaps: The dirt present on clothes is organic in nature and insoluble in water. Therefore, it cannot be removed by only washing with water. When soap is dissolved in water, its hydrophobic ends attach themselves to the dirt and remove it from the cloth. Then, the molecules of soap arrange themselves in micelle formation and trap the dirt at the centre of the cluster. These micelles remain suspended in the water. Hence, the dust particles are easily rinsed away by water.
Carbon and Its Compounds Important Questions: Key Topics for Class 10
Here are the important points from Chapter 4, Science Class 10: Carbon and Its Compounds:
1. Versatility of Carbon
- Carbon’s ability to form a wide variety of compounds due to its unique bonding properties (covalent bonds, formation of chains, rings, etc.).
Types of Carbon Compounds
- Hydrocarbons: Organic compounds made of only carbon and hydrogen.
- Alkanes: Saturated hydrocarbons with single bonds (e.g., methane, ethane).
- Alkenes: Unsaturated hydrocarbons with at least one double bond (e.g., ethene).
- Alkynes: Unsaturated hydrocarbons with at least one triple bond (e.g., ethyne).
- Derivatives of Hydrocarbons: Compounds formed by replacing hydrogen atoms with other elements like halogens, oxygen, or nitrogen.
- Hydrocarbons: Organic compounds made of only carbon and hydrogen.
Bonding in Carbon Compounds
- Single bonds: Sharing of one pair of electrons (e.g., in alkanes).
- Double bonds: Sharing of two pairs of electrons (e.g., in alkenes).
- Triple bonds: Sharing of three pairs of electrons (e.g., in alkynes).
- The nature of bonding affects the reactivity and physical properties of the compounds.
Functional Groups
- Groups of atoms within molecules that are responsible for the characteristic reactions of those compounds.
Examples:- Hydroxyl group (-OH): Alcohols (e.g., ethanol).
- Aldehyde group (-CHO): Aldehydes (e.g., formaldehyde).
- Carboxyl group (-COOH): Carboxylic acids (e.g., acetic acid).
- Amine group (-NH₂): Amines (e.g., aniline).
- Groups of atoms within molecules that are responsible for the characteristic reactions of those compounds.
IUPAC Nomenclature
- Rules for naming organic compounds based on the number of carbon atoms and type of bonds.
- Prefix, infix, and suffix system for naming alkanes, alkenes, alkynes, alcohols, acids, and other organic compounds.
Reactions of Carbon Compounds
- Combustion: Reaction of carbon compounds with oxygen to produce heat and light, resulting in carbon dioxide and water.
- Oxidation: Addition of oxygen or removal of hydrogen in a compound (e.g., ethanol to acetic acid).
- Substitution reactions: Replacement of a hydrogen atom by a halogen or other atom/group (e.g., halogenation).
Soaps and Detergents
- Soap: A substance made by the reaction of a fat or oil with an alkali. It works by emulsifying oils and dirt so they can be washed away.
- Detergents: Synthetic cleaners that work similarly to soaps but are effective in hard water.
- Structure and working mechanism: Hydrophobic tail and hydrophilic head of soap molecules.
Uses and Applications of Carbon Compounds
- Fuels: Hydrocarbons are widely used as fuels (e.g., methane, petroleum).
- Polymers: Long chains of carbon compounds used to make plastics, rubber, etc.
- Medicines: Many drugs and medicines are based on organic compounds.
- Food and Beverages: Organic compounds like sugars, alcohols, and acids are vital components of food and beverages.
Importance of Carbon Compounds in Daily Life
- Role in biological processes (carbohydrates, proteins, lipids, DNA).
- Industrial applications (e.g., in the manufacturing of polymers, synthetic fibers, and petrochemicals).
These concepts help students understand the foundational ideas behind Organic Chemistry and their practical applications in everyday life.