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Carbon and its Compounds

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Carbon and its Compounds

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Summary

Chapter 4: Carbon and its Compounds

Summary

  • Carbon is a versatile element essential for life and many products we use.
  • Carbon compounds are primarily formed due to carbon's tetravalency and catenation.
  • Covalent bonds are formed by sharing electrons, allowing carbon to bond with itself and other elements.
  • Carbon forms various compounds, including hydrocarbons, alcohols, aldehydes, ketones, and carboxylic acids.
  • Carbon compounds can be saturated (single bonds) or unsaturated (double/triple bonds).
  • The presence of functional groups determines the properties of carbon compounds.
  • Carbon is a major source of fuels and is found in everyday substances like ethanol and ethanoic acid.
  • The structure of carbon allotropes, such as diamond and graphite, leads to different physical properties despite similar chemical properties.

Key Formulas and Definitions

Class of CompoundsPrefix/SuffixExample
Halo alkanePrefix-chloro, bromo, etc.Chloropropane (H-C-C-C-Cl)
AlcoholSuffix -olPropanol (H-C-C-C-OH)
AldehydeSuffix -alPropanal (H-C-C-C=O)
KetoneSuffix -onePropanone (H-C-C-C-H)
Carboxylic acidSuffix -oic acidPropanoic acid (H-C-C-C-OH)
AlkenesSuffix -enePropene (H-C-C=C)
AlkynesSuffix -ynePropyne (H-C≡C-H)

Learning Objectives

  • Describe the significance of carbon in organic compounds.
  • Explain the concept of covalent bonding in carbon compounds.
  • Identify different classes of carbon compounds and their functional groups.
  • Differentiate between saturated and unsaturated carbon compounds.
  • Illustrate the structure of carbon allotropes and their properties.

Common Mistakes and Exam Tips

  • Mistake: Confusing saturated and unsaturated compounds. Tip: Remember that saturated compounds have only single bonds, while unsaturated compounds have double or triple bonds.
  • Mistake: Misidentifying functional groups in carbon compounds. Tip: Familiarize yourself with common functional groups and their suffixes/prefixes.

Important Diagrams

  • Structure of Diamond: Tetrahedral arrangement of carbon atoms forming a rigid structure.
  • Structure of Graphite: Hexagonal arrays of carbon atoms in layers, allowing for conductivity.
  • Methane Molecule (CH₄): Central carbon atom with four overlapping orbitals representing covalent bonds.

Learning Objectives

Learning Objectives

  • Understand the significance of carbon in various compounds.
  • Identify the properties of carbon that contribute to its versatility.
  • Explain the concept of covalent bonding in carbon compounds.
  • Describe the different classes of organic compounds and their nomenclature.
  • Recognize the importance of functional groups in determining the properties of carbon compounds.
  • Differentiate between saturated and unsaturated carbon compounds.
  • Analyze the structure and properties of various carbon allotropes, including diamond and graphite.
  • Explore the concept of homologous series in organic chemistry.

Detailed Notes

Chapter 4: Carbon and its Compounds

Introduction

  • Study of interesting compounds and their properties.
  • Focus on carbon, an element of immense significance.

Importance of Carbon

  • Carbon is present in food, clothes, medicines, and living structures.
  • Earth’s crust contains only 0.02% carbon; atmosphere has 0.03% carbon dioxide.
  • Despite its small amount, carbon's importance is immense.

4.1 Bonding in Carbon - The Covalent Bond

  • Comparison with ionic compounds: ionic compounds have high melting/boiling points and conduct electricity.
  • Carbon forms covalent bonds by sharing electrons.
  • Carbon can form chains: straight, branched, or rings.

4.2 Versatile Nature of Carbon

  • Carbon's tetravalency and catenation lead to a vast number of compounds.
  • Covalent bonds allow carbon to bond with itself and other elements (H, O, S, N, Cl).
  • Carbon compounds can be saturated (single bonds) or unsaturated (double/triple bonds).

4.2.1 Saturated and Unsaturated Carbon Compounds

  • Saturated Compounds: Only single bonds (e.g., Ethane - C₂H₆).
  • Unsaturated Compounds: Contain double or triple bonds (e.g., Ethene - C₂H₄).

4.2.2 Homologous Series

  • Series of compounds with the same functional group but different carbon chain lengths.
  • Example: Alcohols (Methanol, Ethanol, Propanol, Butanol).

4.2.3 Nomenclature of Carbon Compounds

  • Naming based on carbon chain and functional group.
  • Method:
    1. Identify number of carbon atoms.
    2. Indicate functional group with prefix/suffix.
    3. Modify name if suffix begins with a vowel.
    4. Change 'ane' to 'ene' or 'yne' for unsaturated compounds.

Table 4.4: Nomenclature of Organic Compounds

Class of compoundsPrefix/SuffixExample
1. Halo alkanePrefix-chloro, bromo, etc.Chloropropane (H-C-C-C-Cl)
2. AlcoholSuffix - olPropanol (H-C-C-C-OH)
3. AldehydeSuffix - alPropanal (H-C-C-C=O)
4. KetoneSuffix - onePropanone (H-C-C-C-H)
5. Carboxylic acidSuffix oic acidPropanoic acid (H-C-C-C-OH)
6. AlkenesSuffix - enePropene (H-C-C=C)
7. AlkynesSuffix - ynePropyne (H-C≡C-H)

Conclusion

  • Carbon's unique properties allow for a vast array of compounds, essential for life and various applications.

Exam Tips & Common Mistakes

Common Mistakes and Exam Tips

Common Pitfalls

  • Misidentifying Functional Groups: Students often confuse functional groups such as alcohols, aldehydes, and ketones. Ensure you understand the suffixes and prefixes associated with each class of compounds.
  • Incorrect Bonding Representation: When drawing structures, students may forget to represent double or triple bonds correctly, leading to inaccurate molecular representations.
  • Neglecting Carbon's Tetravalency: Failing to account for carbon's tetravalency can result in incorrect molecular formulas and structures.
  • Overlooking Isomerism: Students may not consider structural isomers when asked about compounds with the same molecular formula.

Tips for Success

  • Practice Drawing Structures: Regularly practice drawing the structures of various carbon compounds to reinforce your understanding of bonding and functional groups.
  • Memorize Prefixes and Suffixes: Familiarize yourself with the nomenclature rules for organic compounds, including common prefixes and suffixes for functional groups.
  • Understand Homologous Series: Recognize the patterns in homologous series, including how the properties change with increasing molecular mass.
  • Review Properties of Compounds: Make sure to review the physical and chemical properties of different classes of carbon compounds to answer comparative questions effectively.

Practice & Assessment

Multiple Choice Questions

A.

An alcohol

B.

A haloalkane

C.

An aldehyde

D.

A carboxylic acid
Correct Answer: B

Solution:

Replacing a hydrogen atom in methane with a chlorine atom results in the formation of a haloalkane, specifically chloromethane.

A.

It is an alkene.

B.

It is an alkyne.

C.

It is an alkane.

D.

It is an aromatic compound.
Correct Answer: C

Solution:

The molecular formula C₅H₁₂ corresponds to an alkane, as it follows the general formula CₙH₂ₙ₊₂ for alkanes. Alkenes and alkynes have fewer hydrogen atoms relative to their carbon atoms.

A.

1

B.

2

C.

3

D.

4
Correct Answer: D

Solution:

Methane (CH₄) consists of one carbon atom bonded to four hydrogen atoms, resulting in four covalent bonds as shown in its electron dot structure.

A.

C₄H₁₀

B.

C₆H₁₂

C.

C₆H₆

D.

C₅H₁₀
Correct Answer: B

Solution:

Cyclohexane has the molecular formula C₆H₁₂ and consists of a ring of six carbon atoms.

A.

Ethanoic acid

B.

Ethene

C.

Methane

D.

Ethyl acetate
Correct Answer: B

Solution:

When ethanol is heated with excess concentrated sulfuric acid at 443 K, it undergoes dehydration to form ethene (CH₂=CH₂) and water. Sulfuric acid acts as a dehydrating agent.

A.

Hydrogenation of vegetable oils

B.

Oxidation of ethanol to ethanoic acid

C.

Chlorination of methane

D.

Dehydration of ethanol to ethene
Correct Answer: C

Solution:

In the chlorination of methane, chlorine replaces hydrogen atoms, making it a substitution reaction.

A.

Functional group

B.

Heteroatom

C.

Isomer

D.

Catalyst
Correct Answer: B

Solution:

In a substitution reaction where a chlorine atom replaces a hydrogen atom in a hydrocarbon chain, the chlorine atom is referred to as a heteroatom. Heteroatoms are elements that replace hydrogen in carbon compounds, providing specific properties to the compound.

A.

Carboxylic acid

B.

Aldehyde

C.

Ketone

D.

Alcohol
Correct Answer: C

Solution:

Butanone contains the ketone functional group, which is characterized by the carbonyl group (C=O) within the carbon chain.

A.

Oxidation with KMnO₄

B.

Dehydration using concentrated H₂SO₄

C.

Hydrogenation with Ni catalyst

D.

Substitution with Cl₂
Correct Answer: B

Solution:

Ethanol is converted to ethene by dehydration, which involves heating ethanol with concentrated sulfuric acid (H₂SO₄) to remove water.

A.

Each carbon atom is bonded to four other carbon atoms in a tetrahedral structure.

B.

Each carbon atom is bonded to three other carbon atoms in a planar hexagonal structure.

C.

Graphite is an insulator due to its strong covalent bonds.

D.

Graphite has a three-dimensional network similar to diamond.
Correct Answer: B

Solution:

In graphite, each carbon atom is bonded to three other carbon atoms in a planar hexagonal structure, allowing layers to slide over each other, which makes graphite a good conductor of electricity.

A.

Ethanol is a solid at room temperature.

B.

Ethanol is insoluble in water.

C.

Ethanol is a good solvent and is soluble in water.

D.

Ethanol is a gas at room temperature.
Correct Answer: C

Solution:

Ethanol is a liquid at room temperature and is soluble in water, making it a good solvent.

A.

Carbon forms only single bonds with other elements.

B.

Carbon can form double and triple bonds with itself.

C.

Carbon is not found in living organisms.

D.

Carbon compounds are poor conductors of electricity.
Correct Answer: B

Solution:

Carbon can form double and triple bonds with itself, allowing for a variety of structures such as chains and rings.

A.

It is an alkane.

B.

It is an alkene.

C.

It is an alkyne.

D.

It is a cycloalkane.
Correct Answer: C

Solution:

The molecular formula C₄H₆ corresponds to an alkyne, as alkynes have the general formula CₙH₂ₙ₋₂. In this case, n=4, giving C₄H₆.

A.

It is an alkene.

B.

It is an alkyne.

C.

It is an alkane.

D.

It is an aromatic compound.
Correct Answer: C

Solution:

C₄H₁₀ is an alkane, specifically butane, which is a saturated hydrocarbon with single bonds only.

A.

Isotopes

B.

Polymers

C.

Isomers

D.

Allotropes
Correct Answer: C

Solution:

Compounds with the same molecular formula but different structural arrangements are called isomers.

A.

Single bond

B.

Double bond

C.

Triple bond

D.

Ionic bond
Correct Answer: C

Solution:

A nitrogen molecule (N₂) has a triple bond between the two nitrogen atoms.

A.

Ethanol reacting with sodium

B.

Hydrogenation of vegetable oils

C.

Ethanol oxidizing to ethanoic acid

D.

Substitution of chlorine in methane
Correct Answer: B

Solution:

The hydrogenation of vegetable oils is an addition reaction where unsaturated hydrocarbons add hydrogen in the presence of a catalyst.

A.

Oxidizing agent

B.

Reducing agent

C.

Dehydrating agent

D.

Catalyst
Correct Answer: C

Solution:

Concentrated sulphuric acid acts as a dehydrating agent in the dehydration of ethanol, where it removes water from ethanol to produce ethene.

A.

Alcohol

B.

Haloalkane

C.

Ketone

D.

Carboxylic acid
Correct Answer: B

Solution:

When a hydrogen atom in a hydrocarbon is replaced by a chlorine atom, the resulting compound is called a haloalkane, specifically a chloroalkane.

A.

Each carbon atom is bonded to three other carbon atoms.

B.

Each carbon atom is bonded to four other carbon atoms in a rigid three-dimensional structure.

C.

Diamond is a good conductor of electricity.

D.

Diamond is formed by layers of hexagonal arrays.
Correct Answer: B

Solution:

In diamond, each carbon atom is bonded to four other carbon atoms, forming a rigid three-dimensional structure.

A.

Each carbon atom is bonded to four other carbon atoms.

B.

Graphite is a poor conductor of electricity.

C.

Graphite has a hexagonal array of carbon atoms.

D.

Graphite is the hardest known substance.
Correct Answer: C

Solution:

In graphite, each carbon atom is bonded to three other carbon atoms in the same plane, forming a hexagonal array.

A.

It forms ethene and water.

B.

It forms ethanoic acid.

C.

It forms methane.

D.

It forms hydrogen gas.
Correct Answer: A

Solution:

Ethanol undergoes dehydration to form ethene and water when heated with concentrated sulphuric acid.

A.

Isomer

B.

Functional group

C.

Heteroatom

D.

Radical
Correct Answer: C

Solution:

In a hydrocarbon chain, when a hydrogen atom is replaced by another element such as chlorine, the replacing element is referred to as a heteroatom. Heteroatoms confer specific properties to the compound.

A.

C₆H₆, C₆H₁₂, C₆H₁₄

B.

CH₄, C₂H₆, C₃H₈

C.

C₂H₄, C₂H₆, C₃H₆

D.

C₄H₁₀, C₅H₁₀, C₆H₁₀
Correct Answer: B

Solution:

A homologous series is a series of compounds with the same functional group and similar chemical properties, differing by a CH₂ unit. CH₄, C₂H₆, C₃H₈ is an example of such a series.

A.

6

B.

10

C.

12

D.

14
Correct Answer: C

Solution:

Cyclohexane (C₆H₁₂) consists of a ring of six carbon atoms, each bonded to two hydrogen atoms, totaling 12 hydrogen atoms in the molecule.

A.

Alcohol (-OH)

B.

Aldehyde (-CHO)

C.

Carboxylic acid (-COOH)

D.

Ketone (-CO-)
Correct Answer: C

Solution:

The carboxylic acid group (-COOH) is responsible for giving the compound acidic properties due to its ability to donate a proton (H⁺) in solution.

A.

C₄H₁₀

B.

C₆H₁₂

C.

C₆H₆

D.

C₅H₁₀
Correct Answer: B

Solution:

Cyclohexane has the molecular formula C₆H₁₂ and is a cyclic compound.

A.

Concentrated hydrochloric acid

B.

Concentrated sulphuric acid

C.

Dilute sulphuric acid

D.

Sodium hydroxide
Correct Answer: B

Solution:

Concentrated sulphuric acid acts as a dehydrating agent in the reaction: CH3CH2OHConc. H2SO4CH2=CH2+H2OCH_3CH_2OH \xrightarrow{\text{Conc. } H_2SO_4} CH_2=CH_2 + H_2O.

A.

CCl₂O

B.

CCl₃O

C.

C₂Cl₂O

D.

C₂Cl₄O
Correct Answer: A

Solution:

The compound consists of one carbon atom forming a double bond with one oxygen atom and two chlorine atoms satisfying the remaining valencies of carbon. Therefore, the molecular formula is CCl₂O.

A.

Ethene (C₂H₄)

B.

Ethyne (C₂H₂)

C.

Propane (C₃H₈)

D.

Benzene (C₆H₆)
Correct Answer: C

Solution:

Propane (C₃H₈) is a saturated hydrocarbon, also known as an alkane, characterized by single bonds between carbon atoms.

A.

N-N

B.

N=N

C.

N≡N

D.

N=N=N
Correct Answer: C

Solution:

The structural formula for a molecule with a triple bond between two nitrogen atoms is N≡N, representing the nitrogen molecule (N₂).

A.

CH₄ + Cl₂ → CH₃Cl + HCl

B.

CH₃CH₂OH + Na → CH₃CH₂O⁻Na⁺ + H₂

C.

CH₃CH=CH₂ + H₂ → CH₃CH₂CH₃

D.

2CH₃CH₂OH + O₂ → 2CH₃COOH + 2H₂O
Correct Answer: C

Solution:

The reaction CH₃CH=CH₂ + H₂ → CH₃CH₂CH₃ is an addition reaction where hydrogen is added across the double bond of an alkene to form an alkane.

A.

CH₄ + Cl₂ → CH₃Cl + HCl

B.

C₂H₄ + H₂ → C₂H₆

C.

C₆H₆ + O₂ → CO₂ + H₂O

D.

CH₃CH₂OH → CH₂=CH₂ + H₂O
Correct Answer: A

Solution:

The reaction CH₄ + Cl₂ → CH₃Cl + HCl is a substitution reaction where chlorine replaces a hydrogen atom in methane.

A.

Benzene has alternating single and double bonds.

B.

Benzene has a ring structure with delocalized electrons.

C.

Benzene is a straight-chain hydrocarbon.

D.

Benzene contains a triple bond.
Correct Answer: B

Solution:

Benzene has a ring structure with delocalized electrons, which is often represented by a hexagon with a circle inside, indicating resonance.

A.

6 covalent bonds

B.

7 covalent bonds

C.

8 covalent bonds

D.

9 covalent bonds
Correct Answer: B

Solution:

Ethane has 7 covalent bonds: 6 C-H bonds and 1 C-C bond.

A.

They have high melting and boiling points.

B.

They conduct electricity in molten state.

C.

They are generally poor conductors of electricity.

D.

They are always soluble in water.
Correct Answer: C

Solution:

Covalent compounds are generally poor conductors of electricity because they do not have free ions or charged particles.

A.

Ethane

B.

Ethene

C.

Ethyne

D.

Benzene
Correct Answer: A

Solution:

Ethane is a saturated hydrocarbon because it contains only single bonds between carbon atoms.

A.

Carbon has the ability to form ionic bonds with many elements.

B.

Carbon has a high electronegativity, allowing it to attract many electrons.

C.

Carbon can form stable covalent bonds with other carbon atoms, leading to long chains and rings.

D.

Carbon is abundant in the Earth's crust, making it easy to form compounds.
Correct Answer: C

Solution:

Carbon's ability to form stable covalent bonds with other carbon atoms (catenation) allows it to create long chains and rings, leading to a vast number of compounds.

A.

1s² 2s² 2p⁶ 3s² 3p⁵

B.

1s² 2s² 2p⁶ 3s² 3p⁶

C.

1s² 2s² 2p⁶ 3s² 3p⁴

D.

1s² 2s² 2p⁶ 3s² 3p³
Correct Answer: A

Solution:

Chlorine has an atomic number of 17, so its electronic configuration is 1s² 2s² 2p⁶ 3s² 3p⁵.

A.

All members have the same molecular formula.

B.

Successive members differ by a -CH₂- unit.

C.

All members have identical chemical properties.

D.

All members are gases at room temperature.
Correct Answer: B

Solution:

In a homologous series, successive members differ by a -CH₂- unit, and they often have similar chemical properties but not identical molecular formulas.

A.

One

B.

Two

C.

Three

D.

Four
Correct Answer: C

Solution:

Nitrogen molecules (N₂) have a triple bond between the two nitrogen atoms, which means there are three shared pairs of electrons.

A.

Carbon can form ionic bonds easily.

B.

Carbon has a high atomic mass.

C.

Carbon exhibits catenation and tetravalency.

D.

Carbon is a metal.
Correct Answer: C

Solution:

Carbon's ability to form long chains (catenation) and its tetravalency allow it to form a large number of compounds.

A.

Ethene

B.

Ethanol

C.

Ethane

D.

Ethyl chloride
Correct Answer: B

Solution:

Ethanol (C₂H₅OH) can be oxidized to form ethanoic acid (acetic acid, CH₃COOH) using strong oxidizing agents like potassium permanganate (KMnO₄) or potassium dichromate (K₂Cr₂O₇).

A.

Carbon has a high atomic mass.

B.

Carbon has the ability to form ionic bonds.

C.

Carbon exhibits catenation and tetravalency.

D.

Carbon is a metal.
Correct Answer: C

Solution:

Carbon's versatility is due to its ability to form long chains (catenation) and its tetravalency, allowing it to bond with four other atoms.

A.

Graphite is the hardest known natural material.

B.

Diamond conducts electricity well.

C.

Fullerenes are a type of carbon allotrope.

D.

Graphite has a three-dimensional structure like diamond.
Correct Answer: C

Solution:

Fullerenes are indeed a type of carbon allotrope, characterized by their unique molecular structure, such as C-60, which resembles a football.

A.

Each carbon atom bonded to three hydrogen atoms

B.

Each carbon atom bonded to four hydrogen atoms

C.

Each carbon atom bonded to two hydrogen atoms

D.

Each carbon atom bonded to one hydrogen atom
Correct Answer: B

Solution:

Methane has the formula CH₄, where the carbon atom is bonded to four hydrogen atoms.

A.

1 gram

B.

2 grams

C.

3 grams

D.

4 grams
Correct Answer: B

Solution:

The balanced chemical reaction is: 2Na + 2C₂H₅OH → 2C₂H₅ONa + H₂. The molar mass of ethanol is 46 g/mol. From the equation, 2 moles of ethanol produce 1 mole of H₂ (2 grams). Therefore, 46 grams of ethanol (1 mole) will produce 1 gram of H₂. Hence, the correct answer is 2 grams.

A.

2

B.

4

C.

6

D.

8
Correct Answer: B

Solution:

Ethene (C₂H₄) has two carbon atoms double-bonded to each other, with each carbon atom bonded to two hydrogen atoms, making a total of four hydrogen atoms.

A.

Amino group

B.

Carboxyl group

C.

Hydroxyl group

D.

Carbonyl group
Correct Answer: A

Solution:

The amino group (-NH₂) is known to impart basic properties to a compound because it can accept a proton, making it a base.

A.

Carbon's ability to form ionic bonds.

B.

Carbon's ability to form metallic bonds.

C.

Carbon's tetravalency and catenation.

D.

Carbon's large atomic size.
Correct Answer: C

Solution:

Carbon's tetravalency allows it to form four bonds, and catenation allows it to form long chains and rings.

A.

Each carbon atom is bonded to four other carbon atoms in a three-dimensional structure.

B.

Each carbon atom is bonded to three other carbon atoms in a planar hexagonal array.

C.

Carbon atoms are arranged in a football shape.

D.

Carbon atoms are arranged in a ring structure.
Correct Answer: B

Solution:

In graphite, each carbon atom is bonded to three other carbon atoms in the same plane, forming a hexagonal array.

A.

Addition reaction

B.

Substitution reaction

C.

Elimination reaction

D.

Redox reaction
Correct Answer: B

Solution:

This is a substitution reaction where one hydrogen atom in methane (CH₄) is replaced by a chlorine atom, forming chloromethane (CH₃Cl) and hydrogen chloride (HCl).

A.

Oxidation with KMnO₄

B.

Dehydration with concentrated H₂SO₄

C.

Reduction with Ni catalyst

D.

Hydration with water
Correct Answer: B

Solution:

Ethanol is converted to ethene by dehydration, which involves heating ethanol with concentrated sulphuric acid (H₂SO₄) to remove water.

A.

Ethanol is oxidized to ethanoic acid.

B.

Hydrogen gas is evolved.

C.

Ethanol is dehydrated to form ethene.

D.

Ethanol forms a precipitate.
Correct Answer: B

Solution:

When ethanol reacts with sodium, hydrogen gas is evolved, and sodium ethoxide is formed.

A.

Carbon forms ionic bonds with other elements.

B.

Carbon forms covalent bonds by sharing electrons.

C.

Carbon forms metallic bonds with metals.

D.

Carbon does not form bonds with other elements.
Correct Answer: B

Solution:

Carbon forms covalent bonds by sharing electrons between atoms to achieve a filled outer shell.

A.

Carboxylic acid

B.

Aldehyde

C.

Ketone

D.

Alcohol
Correct Answer: C

Solution:

Butanone contains the ketone functional group, which is characterized by a carbonyl group (C=O) bonded to two carbon atoms.

A.

Single bond

B.

Double bond

C.

Triple bond

D.

Quadruple bond
Correct Answer: C

Solution:

A nitrogen molecule (N₂) is formed by a triple bond between two nitrogen atoms.

A.

CH₃N

B.

CH₂NH

C.

CHN

D.

C₂HN
Correct Answer: C

Solution:

The carbon atom forms a triple bond with nitrogen, using three of its four valencies. The remaining valency is satisfied by one hydrogen atom, resulting in the molecular formula CHN.

A.

-COOH

B.

-CHO

C.

-OH

D.

-C=O
Correct Answer: C

Solution:

The functional group present in alcohols is -OH.

A.

Aldehydes

B.

Ketones

C.

Alcohols

D.

Carboxylic acids
Correct Answer: C

Solution:

The -OH group is characteristic of alcohols. Alcohols are compounds where a hydroxyl group is bonded to a carbon atom.

A.

Its ability to form ionic bonds

B.

Its ability to form covalent bonds

C.

Its ability to form hydrogen bonds

D.

Its ability to form metallic bonds
Correct Answer: B

Solution:

Carbon forms covalent bonds with itself and other elements, allowing it to create a vast number of compounds.

A.

N₂ has a single bond between nitrogen atoms.

B.

N₂ has a double bond between nitrogen atoms.

C.

N₂ has a triple bond between nitrogen atoms.

D.

N₂ has no bond between nitrogen atoms.
Correct Answer: C

Solution:

A nitrogen molecule (N₂) consists of two nitrogen atoms connected by a triple bond, which involves the sharing of three pairs of electrons between the atoms.

A.

Ethyl acetate

B.

Acetaldehyde

C.

Ethene

D.

Ethanol
Correct Answer: A

Solution:

The reaction between ethanoic acid and ethanol in the presence of concentrated sulfuric acid is an esterification reaction, producing ethyl acetate as the main product.

A.

High melting and boiling points

B.

Good electrical conductivity

C.

Poor electrical conductivity

D.

Presence of free ions
Correct Answer: C

Solution:

Covalent compounds are generally poor conductors of electricity because they do not have free ions.

A.

They react vigorously with bromine water.

B.

They are generally unreactive and undergo substitution reactions.

C.

They readily form polymers.

D.

They decolorize potassium permanganate solution.
Correct Answer: B

Solution:

Alkanes are saturated hydrocarbons, making them relatively unreactive. They undergo substitution reactions rather than addition reactions, which are more common for unsaturated hydrocarbons like alkenes and alkynes.

A.

Formation of alcohols

B.

Formation of saturated hydrocarbons

C.

Formation of ketones

D.

Formation of aldehydes
Correct Answer: B

Solution:

Unsaturated hydrocarbons add hydrogen in the presence of catalysts such as nickel to form saturated hydrocarbons. This process is known as hydrogenation.

True or False

Correct Answer: False

Solution:

A molecule of nitrogen (N₂) is connected by a triple bond, not a double bond. This is represented by the structural formula N≡N.

Correct Answer: True

Solution:

Catenation is the ability of carbon to form long chains by bonding with other carbon atoms. This property is unique to carbon and allows it to form a vast number of compounds.

Correct Answer: True

Solution:

The earth's crust contains a small amount of carbon, specifically 0.02%, in the form of minerals such as carbonates and hydrogen-carbonates.

Correct Answer: False

Solution:

Ethanol is soluble in water in all proportions.

Correct Answer: True

Solution:

Graphite's structure allows electrons to move freely between layers, making it a good conductor of electricity.

Correct Answer: False

Solution:

Ethanol is soluble in water in all proportions, making it a versatile solvent.

Correct Answer: True

Solution:

Carbon forms covalent bonds by sharing electrons with other atoms, including other carbon atoms, which allows it to form a wide variety of compounds.

Correct Answer: True

Solution:

Carbon's ability to form covalent bonds with itself and various other elements allows it to create a diverse array of compounds.

Correct Answer: True

Solution:

Carbon can form compounds with double and triple bonds, which are known as unsaturated compounds.

Correct Answer: True

Solution:

Carbon has the ability to form chains of varying lengths, including straight and branched chains, due to its property of catenation.

Correct Answer: True

Solution:

Carbon can form compounds containing double and triple bonds, which leads to the formation of various structures like straight chains, branched chains, or rings.

Correct Answer: False

Solution:

Methane is a saturated hydrocarbon with single bonds between carbon and hydrogen atoms.

Correct Answer: True

Solution:

Methane, with the formula CH₄, is a simple carbon compound and is a major component of bio-gas and Compressed Natural Gas (CNG), making it widely used as a fuel.

Correct Answer: True

Solution:

Carbon is known for its ability to form covalent bonds with a variety of elements, including hydrogen, oxygen, sulphur, nitrogen, and chlorine, due to its tetravalency and catenation properties.

Correct Answer: True

Solution:

The conversion of ethanol to ethanoic acid involves the addition of oxygen, which is characteristic of an oxidation reaction.

Correct Answer: True

Solution:

Graphite is a good conductor of electricity due to the presence of free electrons in its structure.

Correct Answer: True

Solution:

Catenation is the ability of carbon to form long chains by bonding with other carbon atoms. This property is a key reason for the diversity of organic compounds.

Correct Answer: True

Solution:

Saturated hydrocarbons, also known as alkanes, contain only single bonds between carbon atoms.

Correct Answer: True

Solution:

Ethanol is a good solvent and is used in medicines such as tincture iodine and cough syrups.

Correct Answer: True

Solution:

Ethanol is oxidized to ethanoic acid in the presence of oxidizing agents such as acidified potassium dichromate.

Correct Answer: False

Solution:

The earth's crust has only 0.02% carbon in the form of minerals, which is a meagre amount.

Correct Answer: False

Solution:

Graphite is actually a good conductor of electricity due to its structure, where each carbon atom is bonded to three others in layers, allowing electrons to move freely.

Correct Answer: False

Solution:

Methanol is toxic, and even small quantities can cause serious harm, including blindness or death.

Correct Answer: False

Solution:

Carbon can form compounds with single, double, and triple bonds.

Correct Answer: True

Solution:

Ethanol is a liquid at room temperature and is soluble in water in all proportions, making it a versatile solvent.

Correct Answer: True

Solution:

Carbon has the unique ability to form bonds with other atoms of carbon, giving rise to large molecules. This property is called catenation.

Correct Answer: True

Solution:

Heating ethanol with concentrated sulphuric acid results in dehydration, producing ethene and water.

Correct Answer: False

Solution:

Graphite is a good conductor of electricity due to the presence of free electrons.

Correct Answer: True

Solution:

Carbon atoms can be linked by single, double, or triple bonds, allowing for the formation of various compounds.

Correct Answer: False

Solution:

Saturated hydrocarbons are fairly unreactive compared to unsaturated hydrocarbons.

Correct Answer: False

Solution:

Saturated hydrocarbons are generally less reactive than unsaturated hydrocarbons, which contain double or triple bonds that are more reactive.

Correct Answer: False

Solution:

Covalent compounds have strong bonds within the molecule, but weak intermolecular forces, resulting in low melting and boiling points.

Correct Answer: True

Solution:

Covalent bonds are formed by the sharing of electrons between two atoms so that both can achieve a completely filled outermost shell.

Correct Answer: True

Solution:

Methane has a formula CH₄, where carbon shares electrons with four hydrogen atoms.

Correct Answer: False

Solution:

Graphite and diamond have very different physical properties due to the different ways carbon atoms are bonded in each structure.

Correct Answer: False

Solution:

Functional groups confer specific properties to carbon compounds, regardless of the length and nature of the carbon chain.

Correct Answer: True

Solution:

Ethanol is a liquid at room temperature and is soluble in water in all proportions.

Correct Answer: False

Solution:

Covalent compounds are generally poor conductors of electricity because they do not form charged particles.