Carbon and its Compounds

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Class 10 Science Chapter 4 Carbon and its Compounds Important Questions

Here are some critical Chapter 4 Carbon and its Compounds problems for Class 10 Science. These inquiries are intended to aid students in studying for and performing well on the CBSE Class 10 Science Examination 2024–25. Students can clear up their concerns and be ready for the exams by practising different types of questions. By answering these questions, you’ll increase your confidence while also sharpening your problem-solving abilities.

Table of Contents

Introduction

In Chapter 4 of Carbon and its Compounds you will learn about The Covalent Bond, Versatile Nature of Carbon,Chemical Properties of Carbon Compounds,Important Carbon Compounds-Ethanol and Ethanoic Acid,Soaps and Detergents.

Class 10 Carbon and its Compounds Important Questions and Answers

Q 1. Identify the unsaturated compounds from the following:

(i) Propane
(ii) Propene
(iii) Propyne
(iv) Chloropropane

Options

(a) (i) and (ii)
(b) (ii) and (iv)
(c) (iii) and (iv)
(d) (ii) and (iii)

Ans. (d)

Explanation:
Alkanes are known as saturated compounds. All the alkenes and alkynes with double and triple bonds in their carbon atoms are known as unsaturated alkenes. Among the given options, propene is an alkene with the formula $C_3H_6.$ It contains a double bond between two carbon atoms, making it unsaturated. Propyne is an alkyne with the formula $C_3H_4.$ It contains a triple bond between two carbon atoms, making it unsaturated.

Q 2. By how much atomic mass unit successive members of a homologous series vary?

Options

(a) One
(b) Sixteen
(c) Fourteen
(d) Twelve

Ans. (c)

Explanation:
The atomic mass unit (amu) by which successive members of a homologous series of hydrocarbons vary is based on the addition of a $CH_2$ group.
Each successive member of a homologous series of alkanes, for example, differs by one $CH_2$ group, which corresponds to an increase of 14 amu (12 amu for the carbon and 2 amu for the hydrogen).

Q 3. What is the difference in molecular formula of any two consecutive members of a homologous series?

Explanation:
The molecular formula of two consecutive members of a homologous series differ by $CH_2$ .

Q 4. Name two properties of carbon which lead to the formation of a large number of carbon compounds.

Explanation:
Catenation and tetravalency are the two properties of carbon which leads to the formation of a large number of carbon compounds.

Q 5. (i) Name the compound formed when ethanol is heated at 443 K in the presence of conc. H₂SO₄ and draw its electron dot structure. State the role of conc. H₂SO₄ in this reaction. (ii) What is hydrogenation? Explain it with the help of a chemical equation. State the role of this reaction in industry.

Explanation:
(i) When ethanol (C₂H₅OH) is heated at 443 K in the presence of concentrated sulfuric acid (H₂SO₄), it undergoes a dehydration reaction to form ethene (C₂H₄), also known as ethylene. The reaction can be represented as:

$\\C_2H_5OH \underrightarrow{\space \space 443 \text{K, conc. H}_2\text{SO}_4 \space \space } C_2 H_4 + H_2O \\[5 bp]$ Electron Dot Structure of Ethene

Concentrated sulphuric acid can act as a dehydrating agent in the reaction.

(ii) Hydrogenation is a chemical reaction in which hydrogen (H₂) is added to an unsaturated hydrocarbon, resulting in the saturation of the compound. This process generally involves the addition of hydrogen to double or triple bonds in alkenes or alkynes, converting them into alkanes. For example, ethene (C₂H₄), which has a double bond, reacts with hydrogen gas (H₂) to form ethane (C₂H₆), a saturated hydrocarbon.

The industrial applications of hydrogenation are as follows:
· Converts liquid vegetable oils into vegetable ghee.
· Removes sulphur and nitrogen compounds from crude oil.
· Used in the synthesis of various pharmaceutical compounds.

CBSE Class 10 Science Chapter wise Important Questions

Chapter No.	Chapter Name
Chapter 1	Chemical Reactions and Equations
Chapter 2	Acid, Bases and Salts
Chapter 3	Metals and Non-Metals
Chapter 4	Carbon and its Compounds
Chapter 5	Life Processes
Chapter 6	Control and Coordination
Chapter 7	How do Organisms Reproduce
Chapter 8	Heredity
Chapter 9	Light : Reflection and Refraction
Chapter 10	The Human Eye and the Colourful world
Chapter 11	Electricity
Chapter 12	Magnetic Effects of Electric Current
Chapter 13	Our Environment

Conclusion

oswal.io offers a thorough set of questions for learning the topic in a better way if you’re looking to further practise and improve your grasp of the concepts covered in the chapter.

Frequently Asked Questions

Q1. Covalent compounds have low melting and boiling point. Why?

Ans: Covalent compounds have low melting and boiling points because the forces of attraction between molecules of covalent compounds are very weak. On applying a small amount of heat these molecular forces break.

Q2. Write the next homologue of each of the following: (i) $C_2H_4 (ii) C_4H_6$

Ans: (i)

C_2H_4

belongs to alkene series having a general formula,

C_nH_{2n}

.Thus, next homologue will be

C_3H_{2×3} = C_3H_6

‍(ii) C4H6 belongs to the alkyne series having general formula,

C_nH_{2n-2}.

Thus, next homologue will be

C_5H_2\times5-2 = C_5H_8

Q3. Elements forming ionic compounds attain noble gas electronic configuration by either gaining or losing electrons from their valence shells. Explain the reason why carbon cannot attain such a configuration in this manner to form its compounds. Name the type of bonds formed in ionic compounds and in the compounds formed by carbon. Also explain with reason why carbon compounds are generally poor conductors of electricity.

Ans: Ionic compounds are formed either by gaining or losing electrons from the outermost shells, but carbon which has four electrons in its outermost shell cannot form ionic bonds because 1. If carbon forms ionic bonds by gaining four electrons to attain a noble gas configuration then it would be difficult for six protons in the nucleus to hold ten electrons. 2. If carbon forms ionic bonds by loss of four electrons then it would require a lot of energy to remove these electrons from the outermost shell. Due to these reasons carbon forms covalent bonds by sharing the valence electrons. Type of bonds formed in ionic compounds are called electrovalent bonds and the type of bonds formed in carbon compounds are called covalent bonds.

Q4. Give reasons for the following: (i) Element carbon forms compounds mainly by covalent bonding. (ii) Diamonds have a high melting point. (iii) Graphite is a good conductor of electricity

Ans:(i) As carbon has four valence electrons and it can neither lose nor gain our electrons thus, it attains noble gas configuration only by sharing of electrons. I bus, it forms covalent compounds. (ii) In diamond, each carbon atom is bonded to four other carbon atoms forming a rigid three-dimensional structure. This makes diamond the hardest known substance. Thus, it has a high melting point. (iii) In graphite, each carbon atom is bonded to three other carbon atoms by covalent bonds in the same plane giving a hexagonal array. Thus, only three valence electrons are used for bond formation and hence, the fourth valence electron is free to move. As a result, graphite is a good conductor of electricity.

Q5. What are covalent bonds? Show their formation with the help of electron dot structure of methane. Why are covalent compounds generally poor conductors of electricity?

Ans: Covalent bonds are those bonds which are formed by sharing of the valence electrons between two atoms. Electron dot structure of methane is shown in the figure.

Chapter Wise Important Questions for CBSE Board Class 10 Science
Chemical Reactions and Equations
Acid, Bases and Salts
Metals and Non-Metals
Carbon and its Compounds
Life Processes
Control and Coordination
How do Organisms Reproduce
Heredity
Light : Reflection and Refraction
The Human Eye and the Colourful world
Electricity
Magnetic Effects of Electric Current
Our Environment

Class 10 Science Chapter 4 Carbon and its Compounds Important Questions

Introduction

Class 10 Carbon and its Compounds Important Questions and Answers

Q 1. Identify the unsaturated compounds from the following:

(i) Propane (ii) Propene (iii) Propyne (iv) Chloropropane

Options

(a) (i) and (ii) (b) (ii) and (iv) (c) (iii) and (iv) (d) (ii) and (iii)

Q 2. By how much atomic mass unit successive members of a homologous series vary?

Options

(a) One (b) Sixteen (c) Fourteen (d) Twelve

Q 3. What is the difference in molecular formula of any two consecutive members of a homologous series?

Q 4. Name two properties of carbon which lead to the formation of a large number of carbon compounds.

CBSE Class 10 Science Chapter wise Important Questions

Conclusion

Frequently Asked Questions

Q1. Covalent compounds have low melting and boiling point. Why?

Q2. Write the next homologue of each of the following: (i) C_2H_4 (ii) C_4H_6

Q4. Give reasons for the following: (i) Element carbon forms compounds mainly by covalent bonding. (ii) Diamonds have a high melting point. (iii) Graphite is a good conductor of electricity

Q5. What are covalent bonds? Show their formation with the help of electron dot structure of methane. Why are covalent compounds generally poor conductors of electricity?

(i) Propane
(ii) Propene
(iii) Propyne
(iv) Chloropropane

(a) (i) and (ii)
(b) (ii) and (iv)
(c) (iii) and (iv)
(d) (ii) and (iii)

(a) One
(b) Sixteen
(c) Fourteen
(d) Twelve

Q2. Write the next homologue of each of the following: (i) $C_2H_4 (ii) C_4H_6$