NCERT Solutions for Class 10 Science Chapter 4 - Carbon and Its Compounds

Intext Exercise 1

Question 1: What would be the electron dot structure of carbon dioxide which has the formula CO2?

Solution 1: Cross 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.)

Solution 2: Dot structure of a S8 molecule: 

Intext Exercise 2

Question 1: How many structural isomers possible for pentane?

Solution 1:

Three structural isomers for pentane.

(i) CH3CH2CH2CH2CH3

(ii) CH3CH(CH3)CH2CH3

(iii) C(CH3)4

Question 2: What are the two properties of carbon to form a large number of compounds?

Solution 2: The two properties of carbon to form a large number of compounds are:

(i) Catenation − It is the ability to form a bond with itself. It is the self-linking ability. 

(ii) Tetravalency − Carbon can make only four bonds. That arrangement of the atoms is

known as tertravalency.

Question 3: What will be the formula and electron dot structure of cyclopentane? Solution 3: The formula for cyclopentane is C5H10.

Question 4: Draw the structures for the following compounds.

(i) Ethanoic acid

(ii) Bromopentane

(iii) Hexanal

(iv) Butanone

Solution 4:

(i) Ethanoic acid

(ii) CH3CH2CH2CH(Br)CH3

(iii) Hexanal

(iv) Butanone

Question 5: Write the name of the following compounds.

(i)

(ii)

(iii)

Solution 5:

(i) Bromoethane

(ii) Methanal

(iii) Hexyne

Intext Exercise 3

Question 1: Why is the conversion of ethanol to ethanoic acid an oxidation reaction?

Solution 1: The conversion of ethanol to ethanoic acid by the addition of oxygen to ethanol. it is an oxidation reaction.

C2H5OH $\xrightarrow[]{[\text{O}]}$ CH3COOH

Question 2: A mixture of oxygen and ethyne is burnt for welding. Can you tell why a mixture of ethyne and air is not used? 

Solution 2: When ethyne is burnt in the air, it gives a sooty flame due to its unsaturation nature. if ethyne is burnt with oxygen, it gives a clear flame at a temperature of 2500°C because of complete combustion. Oxy-acetylene flame is used for welding. It is difficult to attain this much high temperature without mixing oxygen that's why a mixture of ethyne and air is not used. 

Intext Exercise 4

Question 1: Distinguish experimentally between an alcohol and carboxylic acid.

Solution 1: When alcohol and carboxylic acid react with carbonates and bicarbonates, only carboxylic acid reacts with carbonates and bicarbonates, evolving the CO2 gas that turns lime water milky.

Question 2: What are oxidising agents?

Solution 2: An oxidizing agent is a reactant that removes electrons from other reactants during a redox reaction. For example: Alkaline potassium permanganate (KMnO4) and acidified potassium dichromate(K2Cr2O7)

Intext Exercise 5

Question 1: Would you be able to check if water is hard by using a detergent?

Solution 1: Soaps are the sodium or potassium salt of long chain of carboxylic acid. Detergents are ammonium or sulphonate salts of long chain hydrocarbons. Hard water contains the chloride and sulphates of calcium and magnesium. When soap is added to the hard water forms less lather so some amount of salt is unused. This insoluble salt is known as scum. Detergent will give a good amount of lather in hard water as well as soft water. we can't identify through this that water is hard or soft.

Question 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?

Solution 2:

Soap contains the two parts. One part is hydrophilic and other part is hydrophobic. Soaps are the sodium or potassium salt of long chain of carboxylic acid. When the dirty clothes dip in the soap solution. the hydrophobic ends attach the dirt and form a huge cluster. This cluster is known as micelle and traps the dirt.

NCERT Exercises

Question 1: How many covalent bonds are in C2H6?

(a) 6 covalent bonds.

(b) 8 covalent bonds.

(c) 7 covalent bonds.

(d) 5 covalent bonds.

Solution 1: (c) 7 covalent bonds.

Question 2: What is the functional group in the Butanone?

(a) Ketone

(b) aldehyde.

(c) Ether

(d) alcohol.

Solution 2: (a) ketone.

Question 3: When the bottom of the vessel is getting blackened on the outside while cooking, it shows that

(a) the food is cooked completely.

(b) the fuel is not burning completely.

(c) the food is not cooked.

(d) the fuel is burning completely.

Solution 3: (b) The bottom of the vessel is getting blackened on the outside, then it means that the fuel is not burnt completely.

Question 4: Explain the nature of the covalent bond using the bond formation in CH3Cl.

Solution 4: Carbon is tetravalent in nature. In the outermost shell, carbon has four electrons removal of these electrons needs more energy, and gaining the four electrons needs more energy. To complete the octet, carbon needs to share the four electrons with other carbon atoms or different atoms. Carbon forms one bond with chlorine and three bonds with hydrogen.

Question 5: Draw the cross dot structures of the following compounds.

(a) Ethanoic acid.

(b) H2S.

(c) Propanone.

(d) F2.

Solution 5:

(a) Ethanoic acid.

(b) H2S

(c) Propanone

(d) F2

Question 6: What is a homologous series? Explain with an example.

Solution 6: A homologous series is a series of carbon compounds that have same chemical properties but different physical properties and the differences between two successive compounds is -CH2.

For example: Alkanes family. The general formula of Alkane is CnH2n+2.

Methane CH4

Ethane CH3CH3

Propane CH3CH2CH3

Butane CH3CH2CH2CH3

Question 7: How can ethanol and ethanoic acid be differentiated on the basis of their physical and chemical properties?

Solution 7:

Physical properties:

The melting point of ethanol is -114.1 °C and ethanoic acid is 16.6 °C. Ethanoic acid melting point is below the room temperature it freezes during winters. Ethanol is liquid at room temperature but ethanoic acid is solid at room temperature. Ethanol has pleasant smell and ethanoic acid is vinegar smell.

Chemical Properties:

Ethanol is alcohol and ethanoic acid is carboxylic acid. When alcohol and carboxylic acid

reacts with carbonates and bicarbonates than only carboxlylic acid reacts with carbonates and bicarbonates and evolve the CO2 gas that turns lime water milky.

CH3COOH + NaHCO3 or Na2CO3 CH3COONa + CO2 + H2O 

Question 8: In the electrolytic refining of a metal M, what would you take as the anode, the cathode and the electrolyte?

Solution 8:

In the electrolytic refining of a metal M:

Anode → Impure metal M

Cathode → Pure metal M

Electrolyte → Solution of salt of the metal M

Question 9: Why are carbon and its compounds used as fuels for most applications?

Solution 9: When the saturated carbon compounds burnt with air form a carbon dioxide, water with lot of energy and light. In this reaction, no smoke will produce so less pollution. It is exothermic process. It is used as fuels because high calorific value.

Question 10: Explain the formation of scum when hard water is treated with soap.

Solution 10: Soaps are the sodium or potassium salt of long chain of carboxylic acid. Hard water contains the chloride and sulphates of calcium and magnesium. When soap is added to the hard water form less lather so some amount of salt is unused. This insoluble salt is known as scum.

Question 11: What change will you observe if you test soap with litmus paper (red and blue)?

Solution 11: Soap is basic in nature so red litmus turns blue but blue litmus remains the same.

Question 12: What is hydrogenation? What is its industrial application?

Solution 12: The addition of hydrogen on the unsaturated compounds are known as hydrogenation. It is a addition reaction in the presence of Ni/Pt/Pd as catalyst. Unsaturated compounds convert into the saturated compounds. Through this process, the vegetable oil is converted into ghee. 

Question 13: Which of the following hydrocarbons undergo addition reactions:

C2H6, C3H8, C3H6, C2H2 and CH4.

Solution 13: Unsaturated hydrocarbons undergo addition reactions. The unsaturated hydrocarbons General formula is CnH2n-2 or CnH2n. In the given compounds C3H6 and C2H2 undergo addition reactions while C2H6, C2H8 and CH4 are saturated hydrocarbon.

Question 14: Give a test that can be used to differentiate chemically between butter and cooking oil.

Solution 14: Cooking oil is unsaturated fats but the butter is saturated. By hydrogenation, oil will reacts but butter will not reacts.

Question 15: Explain the mechanism of the cleaning action of soaps.

Solution 15: Cleansing action of soaps:

Soap contains two parts. One part is hydrophilic and other part is hydrophobic. Soaps are the sodium or potassium salt of long chain of carboxylic acid. When the dirty clothes dip in the soap solution. The hydrophobic ends attach the dirt and form a big cluster. This cluster is known as micelle and traps the dirt. 

Ch 4 Science Class 10 Quick Overview of Detailed Structure of Topics 

Important Concepts Covered in Carbon And Its Compounds Class 10

Here are the important points from Chapter 4, Science Class 10: Carbon and Its Compounds:

• Unique Nature of Carbon:

• Carbon can form four covalent bonds (tetravalency).

• It can form single, double, and triple bonds.

• Carbon atoms can bond to form long chains, branched chains, and rings.

• Types of Carbon Compounds:

• Hydrocarbons: Compounds consisting of only carbon and hydrogen.

• Saturated Hydrocarbons (Alkanes): Contain single bonds (e.g., methane, ethane).

• Unsaturated Hydrocarbons: Contain double bonds (alkenes) or triple bonds (alkynes) (e.g., ethene, ethyne).

• Functional Groups:

• Groups of atoms that impart specific properties to organic compounds.

• Examples: Alcohol (-OH), Aldehyde (-CHO), Ketone (-CO-), Carboxylic Acid (-COOH), and Halides (F, Cl, Br, I).

• Nomenclature of Carbon Compounds:

• Rules for naming carbon compounds based on the IUPAC system.

• Prefixes and suffixes denote the number of carbon atoms and the type of bonds/functional groups.

• Homologous Series:

• A series of compounds with the same functional group but different chain lengths.

• Each member differs from the next by a -CH2- unit.

• The properties of compounds change progressively with increasing molecular mass.

• Chemical Properties of Carbon Compounds:

• Combustion: Carbon compounds burn in the presence of oxygen to produce carbon dioxide, water, and energy.

• Oxidation: Alcohols can be oxidised to aldehydes and further to carboxylic acids.

• Addition Reactions: Unsaturated hydrocarbons (alkenes and alkynes) undergo addition reactions (e.g., hydrogenation).

• Substitution Reactions: Saturated hydrocarbons (alkanes) undergo substitution reactions.

• Soaps and detergents work by utilising molecules that have both hydrophobic and hydrophilic parts. This characteristic enables them to break down and disperse oily dirt through emulsification, facilitating removal.

Benefits of Chapter 4 Carbon and Its Compounds Class 10 Solutions

• Class 10 Science Chapter 4 Question Answer provides detailed explanations covering all topics, including the versatile nature of carbon, types of carbon compounds, chemical properties, and nomenclature.

• Carbon And Its Compounds Class 10 PDF gives step-by-step solutions that help understand complex concepts, such as bonding in carbon, functional groups, isomerism, and important reactions, ensuring the clarity of fundamental principles.

• Class 10 Carbon And Its Compounds PDF is prepared by Vedantu’s Master Teachers and provides accurate explanations.

• Vedantu's NCERT Solutions helps students develop effective problem-solving strategies by providing solutions to exercises and questions.

• Class 10 Science Chapter 4 is aligned with the updated CBSE syllabus for Class 10 Science, ensuring that students cover the topics and concepts required for the present academic year.

• Vedantu provides additional resources such as class notes, important concepts, formulas, and exemplar solutions.

Important Study Materials for Carbon and Its Compounds Class 10

Conclusion

Vedantu’s NCERT Solutions for Class 10 Science Chapter 4: Carbon and its Compounds offer valuable assistance to students. These solutions are prepared to simplify complex concepts related to carbon compounds, making them easier to understand. Students must focus on understanding the different types of carbon compounds, their properties, and their uses in daily life. By practising the step-by-step solutions provided, students can strengthen their grasp on this topic and improve their problem-solving skills. In previous year’s question papers, around 8-10 questions were asked in this chapter, emphasising its importance in the examination.

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