Carbon and Its Compounds MCQ Quiz - Objective Question with Answer for Carbon and Its Compounds - Download Free PDF

The correct answer is Isopropyl chloride.

Key Points

• The Friedel-Crafts reaction involves the alkylation or acylation of an aromatic ring using a halide and a Lewis acid catalyst such as AlCl₃.
• Isopropyl chloride (a secondary alkyl halide) is suitable for Friedel-Crafts alkylation as it can generate a stable carbocation intermediate.
• Unsaturated halides like chloroethene and halogenated aromatic compounds (e.g., chlorobenzene and bromobenzene) are generally unreactive in this reaction due to resonance stabilization or lack of carbocation formation.
• The reaction requires the halide to form a strong electrophile, which is not feasible with aromatic halides or halides with sp²-hybridized carbons.
• Isopropyl chloride efficiently undergoes the reaction, forming isopropylbenzene (cumene) as the product in the presence of a Lewis acid catalyst.

Additional Information

• Friedel-Crafts Reaction:
  • A type of electrophilic aromatic substitution reaction used to introduce alkyl or acyl groups into an aromatic ring.
  • Requires a Lewis acid catalyst such as AlCl₃, FeCl₃, or BF₃.
  • The reaction occurs via the formation of a carbocation intermediate or an acylium ion, depending on the halide used.
• Unsuitable Halides:
  • Vinyl halides (e.g., chloroethene) and aryl halides (e.g., chlorobenzene) are not suitable for Friedel-Crafts reactions due to resonance stabilization of the halogen-carbon bond.
  • These compounds fail to form a reactive carbocation intermediate essential for the reaction to proceed.
• Carbocation Stability:
  • The success of Friedel-Crafts alkylation depends on the stability of the intermediate carbocation.
  • Isopropyl chloride forms a secondary carbocation, which is sufficiently stable for the reaction to occur.
• Limitations of Friedel-Crafts Alkylation:
  • Polyalkylation can occur, leading to multiple substitutions on the aromatic ring.
  • Deactivating groups on the aromatic ring reduce the reactivity, and such rings may not undergo the reaction.

The correct answer is CCI4.

Key Points

• Carbon tetrachloride (CCI4) is commonly used in fire extinguishers, particularly in older models.
• CCI4 is effective in extinguishing fires because it is a non-flammable liquid that can inhibit the chemical reactions occurring in a flame.
• It was extensively used in fire extinguishers designed for electrical fires and liquid fires (Class B and C fires).
• Despite its effectiveness, the use of CCI4 has declined due to its toxic and potentially carcinogenic effects.

Additional Information

• Types of Fire Extinguishers
  • Water Extinguishers: Used for Class A fires involving ordinary combustibles like wood and paper.
  • Foam Extinguishers: Effective on Class A and B fires involving flammable liquids.
  • Dry Powder Extinguishers: Suitable for Class A, B, and C fires, used for a wide range of fire types.
  • CO2 Extinguishers: Ideal for electrical fires and flammable liquid fires (Class B and C).
• Fire Extinguisher Classes
  • Class A: Fires involving solid combustibles like wood, paper, and textiles.
  • Class B: Fires involving flammable liquids such as petrol and paint.
  • Class C: Fires involving gases like propane and butane.
  • Class D: Fires involving metals such as magnesium and aluminum.
  • Class K: Fires involving cooking oils and fats.
• Health Risks of CCI4
  • CCI4 can cause liver and kidney damage upon prolonged exposure.
  • It is classified as a probable human carcinogen by the International Agency for Research on Cancer (IARC).
  • Inhalation of CCI4 vapors can lead to central nervous system depression.
• Modern Fire Extinguishers
  • Due to the health risks associated with CCI4, modern fire extinguishers use less toxic and more environmentally friendly agents.
  • Halons and Halocarbons are commonly used in place of CCI4 for electrical and flammable liquid fires.

The correct answer is Lampblack.

Key Points

• Lampblack is a form of carbon that is produced by the incomplete combustion of heavy petroleum products.
• It is classified as an amorphous carbon allotrope, meaning it lacks a well-defined crystalline structure.
• It is primarily used as a pigment in inks, paints, and coatings, as well as in rubber products.
• Lampblack is also known as carbon black and has excellent tinting strength and stability.

Additional Information

• Diamond
  • It is a crystalline allotrope of carbon known for its hardness and high refractive index.
  • Diamonds are used in jewelry and industrial cutting tools.
• Fullerenes
  • These are molecules composed entirely of carbon, taking the form of a hollow sphere, ellipsoid, or tube.
  • Buckminsterfullerene (C60) is the most well-known fullerene, resembling a soccer ball.
• Graphite
  • Graphite is another crystalline form of carbon where atoms are arranged in a hexagonal lattice.
  • It is used in pencils, lubricants, and as a moderator in nuclear reactors.
• Amorphous Carbon
  • Amorphous carbon is a form of carbon that does not have any crystalline structure.
  • Examples include lampblack, coal, and charcoal.

The correct answer is Saturated compounds.

Key Points

• Saturated compounds are those in which the carbon atoms are linked by single bonds only.
• These compounds are also known as alkanes in organic chemistry.
• Saturated compounds generally have the chemical formula CnH2n+2, where n is the number of carbon atoms.
• They are typically less reactive than unsaturated compounds due to the stability of the single carbon-carbon bonds.

Additional Information

• Unsaturated Compounds
  • These compounds contain at least one double or triple bond between carbon atoms.
  • They are more reactive than saturated compounds due to the presence of multiple bonds.
  • Examples include alkenes (with double bonds) and alkynes (with triple bonds).
• Ionic Compounds
  • Formed by the transfer of electrons from one atom to another, creating ions.
  • These compounds are typically formed between metals and non-metals.
  • They exhibit high melting and boiling points and conduct electricity in molten or dissolved states.
• Covalent Compounds
  • Formed by the sharing of electron pairs between atoms.
  • These compounds can be polar or non-polar based on the electronegativity difference between the atoms involved.
  • They generally have lower melting and boiling points compared to ionic compounds.
• Hydrocarbons
  • Organic compounds consisting entirely of hydrogen and carbon.
  • They are classified into alkanes, alkenes, and alkynes based on the type of bonds present.
  • Hydrocarbons are the primary components of fossil fuels like coal, petroleum, and natural gas.

The correct answer is Pure Carbon.
Key Points

• Diamonds are composed of a single element: carbon.
• The carbon atoms in a diamond are arranged in a crystal lattice structure, which gives diamonds their remarkable hardness.
• Each carbon atom in a diamond is bonded to four other carbon atoms through strong covalent bonds.
• This tetrahedral bonding of carbon atoms is what makes diamond the hardest natural substance known.
• Diamonds are typically formed under high-pressure, high-temperature conditions existing at depths of 140 to 190 kilometers (87 to 118 miles) in the Earth's mantle.

Additional Information

• Graphite
  • Graphite is another form of carbon with a different crystal structure.
  • Unlike diamond, graphite is soft and slippery, making it useful as a lubricant and in pencils.
  • In graphite, each carbon atom is bonded to three other carbon atoms in layers of hexagonal lattices.
  • The layers can slide over each other, which accounts for the slippery nature of graphite.
• Allotropes of Carbon
  • Carbon exists in several different forms known as allotropes, including diamond, graphite, and amorphous carbon.
  • Fullerenes and carbon nanotubes are other well-known allotropes of carbon.
  • Each allotrope has unique properties and applications due to the different ways carbon atoms are bonded together.
• Synthetic Diamonds
  • Synthetic diamonds can be produced in laboratories using high-pressure high-temperature (HPHT) methods or chemical vapor deposition (CVD).
  • These diamonds have the same physical and chemical properties as natural diamonds.
  • Synthetic diamonds are used in industrial applications and jewelry.
• Industrial Uses of Diamonds
  • Due to their hardness, diamonds are used in cutting, grinding, and drilling tools.
  • Diamond-tipped tools are essential in the manufacturing and construction industries.
  • Diamonds are also used in high-performance bearings and in optical devices.

The correct answer is 60. 

Key Points

• 60 carbon atoms are organized in interlocking hexagonal and pentagonal rings to form the spherical molecule known as buckminsterfullerene.
• The spherical carbon allotrope known as a buckminsterfullerene (C60) has 60 atoms arranged in pentagons and hexagons, giving it a soccer ball-like form.
• A type of fullerene with the chemical formula C60 is buckminsterfullerene. It is shaped like a football and has a fused-ring construction that resembles a cage. It is made up of twenty hexagons and twelve pentagons. Its 60 carbon atoms are all linked to three of their neighbours.
• Each carbon atom generates three sigma bonds with three other carbon atoms in the fullerene's sp2 hybridization state.

Additional Information

• Carbon fullerene molecules can take on a variety of geometries, including tubes, spheres, cubes, and other pure solids comprised of just one type of atom. A feature of fullerenes is their hollow core, which is an area of empty space inside the molecule.
• Consider a basketball; it has a spherical, leather outside, but a hollow interior where air is trapped to give it its bouncing motion. With a fullerene, the situation is identical. It is entirely composed of carbon, and the interior of the structure is always hollow.
• HIV proteases' hydrophobic cavity can accommodate fullerene, which prevents substrates from reaching the enzyme's catalytic site. It has antioxidant and radical scavenger properties. Fullerene can also produce significant quantum yields of singlet oxygen when exposed to light.

The correct answer is catenation.

Key Points

• Catenation is the ability of an element to form bonds with other atoms of the same element.
• Carbon atoms can form long chains and rings due to their ability to catenate.
• This property allows carbon to form a vast number of compounds, more than any other element.
• Catenation is a crucial property for the formation of organic molecules, including hydrocarbons and polymers.

Additional Information

• Tetravalency of Carbon:
  • Carbon has four valence electrons, allowing it to form four covalent bonds with other atoms, including other carbon atoms.
• Hydrocarbons:
  • Compounds composed solely of carbon and hydrogen. They are categorized into alkanes, alkenes, and alkynes based on the types of bonds between carbon atoms.
• Isomerism:
  • Carbon compounds can exhibit isomerism, where compounds have the same molecular formula but different structural arrangements.
• Polymerization:
  • Carbon compounds can undergo polymerization, where small monomer units join to form large polymers, such as plastics and biological macromolecules.

The correct answer is CCI4.

Key Points

• Carbon tetrachloride (CCI4) is commonly used in fire extinguishers, particularly in older models.
• CCI4 is effective in extinguishing fires because it is a non-flammable liquid that can inhibit the chemical reactions occurring in a flame.
• It was extensively used in fire extinguishers designed for electrical fires and liquid fires (Class B and C fires).
• Despite its effectiveness, the use of CCI4 has declined due to its toxic and potentially carcinogenic effects.

Additional Information

• Types of Fire Extinguishers
  • Water Extinguishers: Used for Class A fires involving ordinary combustibles like wood and paper.
  • Foam Extinguishers: Effective on Class A and B fires involving flammable liquids.
  • Dry Powder Extinguishers: Suitable for Class A, B, and C fires, used for a wide range of fire types.
  • CO2 Extinguishers: Ideal for electrical fires and flammable liquid fires (Class B and C).
• Fire Extinguisher Classes
  • Class A: Fires involving solid combustibles like wood, paper, and textiles.
  • Class B: Fires involving flammable liquids such as petrol and paint.
  • Class C: Fires involving gases like propane and butane.
  • Class D: Fires involving metals such as magnesium and aluminum.
  • Class K: Fires involving cooking oils and fats.
• Health Risks of CCI4
  • CCI4 can cause liver and kidney damage upon prolonged exposure.
  • It is classified as a probable human carcinogen by the International Agency for Research on Cancer (IARC).
  • Inhalation of CCI4 vapors can lead to central nervous system depression.
• Modern Fire Extinguishers
  • Due to the health risks associated with CCI4, modern fire extinguishers use less toxic and more environmentally friendly agents.
  • Halons and Halocarbons are commonly used in place of CCI4 for electrical and flammable liquid fires.

The correct answer is Pure Carbon.
Key Points

• Diamonds are composed of a single element: carbon.
• The carbon atoms in a diamond are arranged in a crystal lattice structure, which gives diamonds their remarkable hardness.
• Each carbon atom in a diamond is bonded to four other carbon atoms through strong covalent bonds.
• This tetrahedral bonding of carbon atoms is what makes diamond the hardest natural substance known.
• Diamonds are typically formed under high-pressure, high-temperature conditions existing at depths of 140 to 190 kilometers (87 to 118 miles) in the Earth's mantle.

Additional Information

• Graphite
  • Graphite is another form of carbon with a different crystal structure.
  • Unlike diamond, graphite is soft and slippery, making it useful as a lubricant and in pencils.
  • In graphite, each carbon atom is bonded to three other carbon atoms in layers of hexagonal lattices.
  • The layers can slide over each other, which accounts for the slippery nature of graphite.
• Allotropes of Carbon
  • Carbon exists in several different forms known as allotropes, including diamond, graphite, and amorphous carbon.
  • Fullerenes and carbon nanotubes are other well-known allotropes of carbon.
  • Each allotrope has unique properties and applications due to the different ways carbon atoms are bonded together.
• Synthetic Diamonds
  • Synthetic diamonds can be produced in laboratories using high-pressure high-temperature (HPHT) methods or chemical vapor deposition (CVD).
  • These diamonds have the same physical and chemical properties as natural diamonds.
  • Synthetic diamonds are used in industrial applications and jewelry.
• Industrial Uses of Diamonds
  • Due to their hardness, diamonds are used in cutting, grinding, and drilling tools.
  • Diamond-tipped tools are essential in the manufacturing and construction industries.
  • Diamonds are also used in high-performance bearings and in optical devices.

The correct answer is Catenation.

Key Points

• Catenation is the ability of an element to form bonds with other atoms of the same element, leading to the formation of chains or rings.
• Carbon exhibits the highest degree of catenation due to its tetravalency, which allows it to form four covalent bonds simultaneously.
• Due to catenation, carbon can form a wide variety of compounds, including long chains, branched chains, and complex ring structures.
• This property is essential for the formation of complex organic molecules, such as proteins, DNA, and synthetic polymers.

Additional Information

• Polymerisation:
  • The process by which small molecules, known as monomers, join together to form a large molecule, or polymer.
  • Examples include the formation of polyethylene from ethylene and the creation of proteins from amino acids.
• Cyclisation:
  • A chemical reaction in which a linear molecule forms a ring structure.
  • Cyclisation is crucial in forming many biological molecules, such as carbohydrates and nucleic acids.
• Metallic Bonding:
  • A type of chemical bonding that arises from the attraction between metal atoms and the surrounding sea of electrons.
  • It explains many properties of metals, including electrical conductivity and malleability.
• Allotropes of Carbon:
  • Carbon exhibits various allotropes due to its catenation property, including diamond, graphite, graphene, and fullerenes.
  • Each allotrope has distinct physical properties due to different arrangements of carbon atoms.

The correct answer is Isopropyl chloride.

Key Points

• The Friedel-Crafts reaction involves the alkylation or acylation of an aromatic ring using a halide and a Lewis acid catalyst such as AlCl₃.
• Isopropyl chloride (a secondary alkyl halide) is suitable for Friedel-Crafts alkylation as it can generate a stable carbocation intermediate.
• Unsaturated halides like chloroethene and halogenated aromatic compounds (e.g., chlorobenzene and bromobenzene) are generally unreactive in this reaction due to resonance stabilization or lack of carbocation formation.
• The reaction requires the halide to form a strong electrophile, which is not feasible with aromatic halides or halides with sp²-hybridized carbons.
• Isopropyl chloride efficiently undergoes the reaction, forming isopropylbenzene (cumene) as the product in the presence of a Lewis acid catalyst.

Additional Information

• Friedel-Crafts Reaction:
  • A type of electrophilic aromatic substitution reaction used to introduce alkyl or acyl groups into an aromatic ring.
  • Requires a Lewis acid catalyst such as AlCl₃, FeCl₃, or BF₃.
  • The reaction occurs via the formation of a carbocation intermediate or an acylium ion, depending on the halide used.
• Unsuitable Halides:
  • Vinyl halides (e.g., chloroethene) and aryl halides (e.g., chlorobenzene) are not suitable for Friedel-Crafts reactions due to resonance stabilization of the halogen-carbon bond.
  • These compounds fail to form a reactive carbocation intermediate essential for the reaction to proceed.
• Carbocation Stability:
  • The success of Friedel-Crafts alkylation depends on the stability of the intermediate carbocation.
  • Isopropyl chloride forms a secondary carbocation, which is sufficiently stable for the reaction to occur.
• Limitations of Friedel-Crafts Alkylation:
  • Polyalkylation can occur, leading to multiple substitutions on the aromatic ring.
  • Deactivating groups on the aromatic ring reduce the reactivity, and such rings may not undergo the reaction.

The correct answer is All of these.

Key Points

• Diamond, Graphite, and Fullerene are all allotropes of carbon, showcasing different structural arrangements of carbon atoms.
• Diamond: A three-dimensional network where each carbon atom is tetrahedrally bonded to four others, making it the hardest natural substance.
• Graphite: A layered structure where carbon atoms are arranged in hexagonal sheets, held together by weak van der Waals forces, making it a good lubricant and conductor of electricity.
• Fullerene: Molecules composed entirely of carbon, arranged in the form of a hollow sphere, ellipsoid, or tube (e.g., Buckminsterfullerene, or C₆₀, resembling a soccer ball).
• These allotropes exhibit different properties due to variations in bonding and structure, despite being made of the same element, carbon.

Additional Information

• Allotropes: Different structural forms of the same element in the same physical state, with distinct physical and chemical properties.
• Carbon Nanotubes: Another allotrope of carbon, where atoms form cylindrical structures, known for their exceptional strength and electrical conductivity.
• Amorphous Carbon: A non-crystalline form of carbon, including substances like charcoal and carbon black, used in various industrial applications.
• Applications of Allotropes: Diamond is used in cutting tools and jewelry, graphite in pencils and lubricants, and fullerenes in nanotechnology and materials science.
• Unique Property: Carbon's ability to form multiple allotropes arises from its versatility in forming single, double, and triple bonds, and its ability to hybridize in different ways (sp, sp², sp³).

The correct answer is Soot.

Key Points

• Black carbon aerosol, commonly known as soot, is a significant component of particulate matter (PM).
• Soot is primarily produced from the incomplete combustion of fossil fuels, biofuel, and biomass.
• It consists of fine particles that are less than 2.5 micrometers in diameter (PM2.5).
• These particles are known to have adverse health effects, including respiratory and cardiovascular diseases.
• Black carbon aerosol contributes to global warming as it absorbs sunlight and heats the atmosphere.

Additional Information

• Smog: A type of air pollution that is a mixture of smoke and fog, typically resulting from industrial and vehicular emissions.
• Smoke: A visible suspension of carbon or other particles in the air, typically produced by burning organic matter.
• Ozone: A reactive molecule composed of three oxygen atoms, found both in the Earth's upper atmosphere (where it is protective) and at ground level (where it is a pollutant).
• Particulate Matter (PM2.5): Fine inhalable particles, with diameters generally 2.5 micrometers and smaller, which can pose health risks when inhaled.
• Black carbon's impact on climate is distinct from long-lived greenhouse gases as it has a shorter atmospheric lifetime but is highly effective at absorbing sunlight and heating the atmosphere.

The Correct answer is Unique ability to form bonds with other atoms of carbon.

Key Points

• Catenation is the property by which carbon atoms form strong covalent bonds with other carbon atoms to produce long chains, branched structures, or rings.
• This unique property arises due to the small size of carbon and the strength of the carbon-carbon bond, which is stronger than bonds formed by most other elements with themselves.
• Carbon exhibits this property more prominently than other elements because of its ability to form single, double, and triple covalent bonds with itself.
• Catenation allows carbon to form a vast number of compounds, making it the basis of organic chemistry and life.
• Examples of compounds formed due to catenation include hydrocarbons (alkanes, alkenes, alkynes), as well as more complex molecules like proteins, carbohydrates, and DNA.
• This property also explains the diversity of carbon compounds, which is unmatched by any other element in the periodic table.

 Additional Information

• Unique ability to form bonds with other atoms of hydrogen
  • Hydrogen bonds with carbon to form hydrocarbons, but this does not define the property of catenation.
  • Hydrocarbons like methane (CH₄) are formed due to the bonding between carbon and hydrogen, but this is not specific to the unique bonding of carbon with itself.
• Unique ability to form bonds with other atoms of nitrogen
  • Nitrogen can form bonds with carbon in amino acids and other organic molecules, but it does not exhibit the extensive catenation property like carbon.
  • Nitrogen primarily forms triple bonds in diatomic nitrogen (N₂), which is stable but unrelated to carbon's catenation.
• Unique ability to form bonds with other atoms of oxygen
  • Oxygen forms bonds with carbon in functional groups like alcohols (-OH), carboxylic acids (-COOH), and ketones (>C=O).
  • However, oxygen does not form long chains or networks by bonding with itself, unlike carbon.

The correct answer is 60. 

Key Points

• 60 carbon atoms are organized in interlocking hexagonal and pentagonal rings to form the spherical molecule known as buckminsterfullerene.
• The spherical carbon allotrope known as a buckminsterfullerene (C60) has 60 atoms arranged in pentagons and hexagons, giving it a soccer ball-like form.
• A type of fullerene with the chemical formula C60 is buckminsterfullerene. It is shaped like a football and has a fused-ring construction that resembles a cage. It is made up of twenty hexagons and twelve pentagons. Its 60 carbon atoms are all linked to three of their neighbours.
• Each carbon atom generates three sigma bonds with three other carbon atoms in the fullerene's sp2 hybridization state.

Additional Information

• Carbon fullerene molecules can take on a variety of geometries, including tubes, spheres, cubes, and other pure solids comprised of just one type of atom. A feature of fullerenes is their hollow core, which is an area of empty space inside the molecule.
• Consider a basketball; it has a spherical, leather outside, but a hollow interior where air is trapped to give it its bouncing motion. With a fullerene, the situation is identical. It is entirely composed of carbon, and the interior of the structure is always hollow.
• HIV proteases' hydrophobic cavity can accommodate fullerene, which prevents substrates from reaching the enzyme's catalytic site. It has antioxidant and radical scavenger properties. Fullerene can also produce significant quantum yields of singlet oxygen when exposed to light.