1. Carbon belongs to which group of the periodic table?
A) Group 13
B) Group 14
C) Group 15
D) Group 16
Answer: B) Group 14
Explanation: Carbon is a group 14 element (tetrels) with 4 valence electrons.
2. The atomic number of carbon is:
A) 4
B) 6
C) 8
D) 12
Answer: B) 6
Explanation: Carbon has 6 protons and thus atomic number = 6.
3. The ability of carbon to form long chains and rings is called:
A) Isomerism
B) Catenation
C) Polymerization
D) Hybridization
Answer: B) Catenation
Explanation: Catenation is the property of an element to form bonds with itself.
4. Which allotrope of carbon is the hardest natural substance?
A) Graphite
B) Diamond
C) Fullerene
D) Charcoal
Answer: B) Diamond
Explanation: Diamond is the hardest naturally occurring material due to 3D covalent bonding.
5. Graphite conducts electricity because:
A) It has free protons
B) It has delocalized electrons
C) It contains ions
D) It is metallic
Answer: B) It has delocalized electrons
Explanation: Each carbon in graphite forms 3 bonds; the 4th electron is free to move.
6. Which of the following is a crystalline allotrope of carbon?
A) Coke
B) Lampblack
C) Diamond
D) Charcoal
Answer: C) Diamond
Explanation: Diamond, graphite, and fullerenes are crystalline allotropes.
7. Buckminsterfullerene (C60) resembles the shape of a:
A) Cube
B) Sphere
C) Football
D) Pyramid
Answer: C) Football
Explanation: Fullerene (C60) has a soccer-ball-like structure.
8. The oxidation state of carbon in CO2 is:
A) +2
B) +4
C) -2
D) 0
Answer: B) +4
Explanation: Oxygen is -2, hence carbon = +4.
9. Which hybridization is present in diamond?
A) sp
B) sp²
C) sp³
D) dsp²
Answer: C) sp³
Explanation: Diamond has tetrahedral geometry with sp³ hybridization.
10. Which is the softest form of carbon?
A) Diamond
B) Graphite
C) Fullerene
D) Charcoal
Answer: B) Graphite
Explanation: Layers in graphite slide over each other due to weak Van der Waals forces.
11. Which property makes carbon form a large number of compounds?
A) Low ionization energy
B) Catenation and tetravalency
C) High electronegativity
D) Metallic bonding
Answer: B) Catenation and tetravalency
Explanation: Carbon forms strong covalent bonds and long chains.
12. Which of the following is not an allotrope of carbon?
A) Graphite
B) Diamond
C) Fullerene
D) Rust
Answer: D) Rust
Explanation: Rust is hydrated ferric oxide, not a carbon allotrope.
13. Graphene is a:
A) 2D sheet of carbon atoms
B) 3D solid structure
C) Amorphous carbon
D) Compound of carbon and hydrogen
Answer: A) 2D sheet of carbon atoms
Explanation: Graphene is a single layer of carbon atoms in honeycomb structure.
14. Which allotrope of carbon is used in lead pencils?
A) Diamond
B) Graphite
C) Charcoal
D) Fullerene
Answer: B) Graphite
Explanation: Pencil “lead” contains graphite mixed with clay.
15. The percentage of carbon in diamond is:
A) 90%
B) 95%
C) 99%
D) 100%
Answer: D) 100%
Explanation: Diamond is pure crystalline carbon.
16. In which allotrope of carbon are carbon atoms arranged in tetrahedral units?
A) Diamond
B) Graphite
C) Fullerene
D) Coal
Answer: A) Diamond
Explanation: Diamond atoms are tetrahedrally bonded.
17. Which of the following is amorphous carbon?
A) Diamond
B) Graphite
C) Charcoal
D) Fullerene
Answer: C) Charcoal
Explanation: Charcoal lacks definite crystalline structure.
18. Which property of carbon explains the existence of isomers?
A) High electronegativity
B) Catenation
C) Tetravalency
D) Both B and C
Answer: D) Both B and C
Explanation: Long chains and different arrangements cause isomerism.
19. Which allotrope of carbon is a good lubricant?
A) Graphite
B) Diamond
C) Fullerene
D) Coal
Answer: A) Graphite
Explanation: Graphite layers slide easily, used as a dry lubricant.
20. Which form of carbon is used in making electrodes?
A) Diamond
B) Graphite
C) Fullerene
D) Coal
Answer: B) Graphite
Explanation: Graphite conducts electricity, hence used in electrodes.
21. Dry ice is the solid form of:
A) Methane
B) Carbon
C) Carbon dioxide
D) Carbon monoxide
Answer: C) Carbon dioxide
Explanation: Solid CO₂ is called dry ice.
22. Which carbon allotrope is known as the “wonder material”?
A) Diamond
B) Graphene
C) Coal
D) Fullerene
Answer: B) Graphene
Explanation: Graphene is super strong, light, and conductive.
23. The hybridization of carbon in graphite is:
A) sp
B) sp²
C) sp³
D) sp³d²
Answer: B) sp²
Explanation: Graphite has planar hexagonal sheets with sp² bonding.
24. Which compound of carbon is poisonous and binds with hemoglobin?
A) CO₂
B) CO
C) CH₄
D) C₂H₂
Answer: B) CO
Explanation: Carbon monoxide binds with hemoglobin to form carboxyhemoglobin.
25. The main component of biogas is:
A) CO₂
B) CH₄
C) C₂H₆
D) H₂
Answer: B) CH₄
Explanation: Methane (CH₄) is about 70% of biogas.
26. The general formula of alkanes is:
A) CnH2n
B) CnH2n+2
C) CnH2n–2
D) CnHn
Answer: B) CnH2n+2
Explanation: Alkanes are saturated hydrocarbons with single bonds only.
27. The first member of the alkane series is:
A) Methane
B) Ethane
C) Propane
D) Butane
Answer: A) Methane
Explanation: Methane (CH₄) is the simplest alkane.
28. The general formula of alkenes is:
A) CnH2n
B) CnH2n+2
C) CnH2n–2
D) CnH2n+1
Answer: A) CnH2n
Explanation: Alkenes are unsaturated hydrocarbons with one double bond.
29. The simplest alkene is:
A) Ethene
B) Methene
C) Propene
D) Butene
Answer: A) Ethene
Explanation: “Methene” does not exist, hence ethene (C₂H₄) is the first alkene.
30. The general formula of alkynes is:
A) CnH2n
B) CnH2n–2
C) CnH2n+2
D) CnHn
Answer: B) CnH2n–2
Explanation: Alkynes are unsaturated hydrocarbons with one triple bond.
31. The first member of the alkyne series is:
A) Ethyne
B) Methyne
C) Propyne
D) Butyne
Answer: A) Ethyne
Explanation: Methyne is not possible. The first alkyne is ethyne (C₂H₂).
32. Which hydrocarbon is called “paraffin”?
A) Alkenes
B) Alkynes
C) Alkanes
D) Aromatics
Answer: C) Alkanes
Explanation: Alkanes are chemically less reactive, hence called paraffins (Latin: “little affinity”).
33. Which gas is popularly known as “marsh gas”?
A) Ethane
B) Methane
C) Propane
D) Butane
Answer: B) Methane
Explanation: Methane (CH₄) is found in marshy areas due to anaerobic decay.
34. Which of the following hydrocarbons undergo addition reactions?
A) Alkanes
B) Alkenes
C) Aromatics
D) All of these
Answer: B) Alkenes
Explanation: Alkenes and alkynes undergo addition due to double/triple bonds, but alkanes don’t.
35. The IUPAC name of acetylene is:
A) Ethene
B) Ethyne
C) Ethane
D) Propyne
Answer: B) Ethyne
Explanation: Common name acetylene = IUPAC name ethyne (C₂H₂).
36. Which of the following is aromatic?
A) Benzene
B) Methane
C) Ethene
D) Propyne
Answer: A) Benzene
Explanation: Benzene (C₆H₆) is the simplest aromatic hydrocarbon.
37. Which catalyst is used in the hydrogenation of alkenes?
A) Ni or Pt
B) Fe
C) Cu
D) Pb
Answer: A) Ni or Pt
Explanation: Hydrogenation requires catalysts like nickel, platinum, or palladium.
38. The addition of HCl to ethene is an example of:
A) Substitution reaction
B) Addition reaction
C) Elimination reaction
D) Polymerization
Answer: B) Addition reaction
Explanation: Alkenes react with HCl in an addition reaction forming chloroethane.
39. Which is used in oxy-acetylene flame for welding?
A) Ethane
B) Ethene
C) Ethyne
D) Methane
Answer: C) Ethyne
Explanation: Ethyne + oxygen burns with a very high temperature (~3000°C).
40. Which hydrocarbon undergoes substitution reactions easily?
A) Alkanes
B) Alkenes
C) Alkynes
D) Aromatics
Answer: A) Alkanes
Explanation: Alkanes undergo substitution reactions with halogens in presence of sunlight.
41. The compound benzene (C₆H₆) was discovered by:
A) Kekulé
B) Faraday
C) Dalton
D) Mendeleev
Answer: B) Faraday
Explanation: Michael Faraday first isolated benzene in 1825.
42. The structure of benzene was proposed by:
A) Kekulé
B) Dalton
C) Arrhenius
D) Avogadro
Answer: A) Kekulé
Explanation: August Kekulé proposed the cyclic structure with alternating double bonds.
43. Which of the following hydrocarbons decolorizes bromine water?
A) Alkanes
B) Alkenes
C) Aromatics
D) All of these
Answer: B) Alkenes
Explanation: Alkenes/alkynes decolorize bromine water due to addition reaction.
44. Which of the following hydrocarbons shows isomerism?
A) Methane
B) Ethane
C) Propane
D) Butane
Answer: D) Butane
Explanation: Butane has two structural isomers: n-butane and isobutane.
45. Toluene is also called:
A) Methylbenzene
B) Ethylbenzene
C) Phenylmethane
D) Benzyl alcohol
Answer: A) Methylbenzene
Explanation: Toluene = C₆H₅–CH₃.
46. Which hydrocarbon is known as “acetylene”?
A) Ethene
B) Ethyne
C) Propene
D) Butyne
Answer: B) Ethyne
Explanation: Ethyne is the IUPAC name for acetylene.
47. Which gas is called “illuminating gas”?
A) Hydrogen
B) Acetylene
C) Methane
D) Ethane
Answer: B) Acetylene
Explanation: Ethyne burns with a bright luminous flame, used in lamps earlier.
48. Benzene undergoes:
A) Addition reaction
B) Substitution reaction
C) Elimination reaction
D) None of these
Answer: B) Substitution reaction
Explanation: Benzene resists addition; it undergoes electrophilic substitution to retain aromaticity.
49. Which is an example of an alkyne?
A) CH₄
B) C₂H₂
C) C₂H₄
D) C₆H₆
Answer: B) C₂H₂
Explanation: Ethyne is the simplest alkyne.
50. Which hydrocarbon is used as LPG fuel?
A) Methane
B) Ethane
C) Propane and Butane
D) Ethyne
Answer: C) Propane and Butane
Explanation: LPG mainly contains propane (C₃H₈) and butane (C₄H₁₀).
51. A functional group in chemistry is:
A) A part of compound which is inert
B) The group responsible for characteristic reactions
C) The longest carbon chain
D) The side chain of hydrocarbons
Answer: B) The group responsible for characteristic reactions
Explanation: Functional groups determine the physical and chemical properties of compounds.
52. The functional group of alcohols is:
A) –CHO
B) –COOH
C) –OH
D) –CO–
Answer: C) –OH
Explanation: Alcohols contain the hydroxyl group (–OH).
53. The functional group of aldehydes is:
A) –CHO
B) –OH
C) –COOH
D) –NH₂
Answer: A) –CHO
Explanation: Aldehydes contain the carbonyl group attached to a hydrogen.
54. The functional group of carboxylic acids is:
A) –CHO
B) –OH
C) –COOH
D) –CO–
Answer: C) –COOH
Explanation: Carboxyl group (–COOH) characterizes acids like acetic acid.
55. The functional group of ketones is:
A) –CHO
B) –OH
C) –CO–
D) –NH₂
Answer: C) –CO–
Explanation: Ketones contain a carbonyl group bonded to two carbons.
56. The functional group of amines is:
A) –NH₂
B) –NO₂
C) –CN
D) –OH
Answer: A) –NH₂
Explanation: Amines contain amino group (–NH₂).
57. Ethanol is commonly known as:
A) Methanol
B) Wood spirit
C) Grain alcohol
D) Glycerol
Answer: C) Grain alcohol
Explanation: Ethanol is obtained by fermentation of sugars.
58. Methanol is also called:
A) Wood alcohol
B) Rectified spirit
C) Ethyl alcohol
D) Methylated spirit
Answer: A) Wood alcohol
Explanation: Methanol is obtained by destructive distillation of wood.
59. Which alcohol is poisonous and causes blindness?
A) Ethanol
B) Methanol
C) Propanol
D) Butanol
Answer: B) Methanol
Explanation: Methanol is highly toxic, causing blindness and death.
60. The formula of ethanol is:
A) CH₃OH
B) C₂H₅OH
C) C₃H₇OH
D) C₄H₉OH
Answer: B) C₂H₅OH
Explanation: Ethanol = CH₃–CH₂–OH.
61. Vinegar is a dilute solution of:
A) Methanol
B) Ethanol
C) Acetic acid
D) Formic acid
Answer: C) Acetic acid
Explanation: Vinegar is ~5–8% aqueous acetic acid (CH₃COOH).
62. The molecular formula of acetic acid is:
A) CH₃OH
B) C₂H₅OH
C) CH₃COOH
D) HCOOH
Answer: C) CH₃COOH
Explanation: Acetic acid contains the carboxyl group.
63. The simplest carboxylic acid is:
A) Formic acid
B) Acetic acid
C) Propionic acid
D) Oxalic acid
Answer: A) Formic acid
Explanation: Formic acid (HCOOH) is the simplest carboxylic acid.
64. Formaldehyde has the formula:
A) HCHO
B) CH₃CHO
C) CH₃COOH
D) HCOOH
Answer: A) HCHO
Explanation: Formaldehyde is the simplest aldehyde.
65. Acetaldehyde has the formula:
A) HCHO
B) CH₃CHO
C) CH₃COOH
D) C₂H₅OH
Answer: B) CH₃CHO
Explanation: Acetaldehyde belongs to aldehydes (–CHO).
66. The IUPAC name of formaldehyde is:
A) Methanal
B) Ethanal
C) Methanol
D) Formic acid
Answer: A) Methanal
Explanation: Aldehydes are named as “–anal.” HCHO = methanal.
67. The IUPAC name of acetaldehyde is:
A) Methanal
B) Ethanal
C) Propanal
D) Butanal
Answer: B) Ethanal
Explanation: CH₃–CHO is ethanal.
68. The IUPAC name of acetic acid is:
A) Methanoic acid
B) Ethanoic acid
C) Propanoic acid
D) Butanoic acid
Answer: B) Ethanoic acid
Explanation: CH₃COOH is ethanoic acid.
69. Which of the following is used as an antiseptic in low concentration and as a disinfectant in high concentration?
A) Formaldehyde
B) Ethanol
C) Phenol
D) Methanol
Answer: C) Phenol
Explanation: Phenol is antiseptic at 0.1% but disinfectant at higher concentration.
70. The reaction of alcohol with sodium metal produces:
A) Hydrogen gas
B) Oxygen gas
C) Carbon dioxide
D) Nitrogen gas
Answer: A) Hydrogen gas
Explanation: 2R–OH + 2Na → 2R–ONa + H₂↑.
71. Oxidation of ethanol with alkaline KMnO₄ produces:
A) Methanol
B) Acetaldehyde
C) Acetic acid
D) Propanol
Answer: C) Acetic acid
Explanation: Ethanol is oxidized stepwise to acetaldehyde, then acetic acid.
72. Which reagent is used to distinguish between aldehydes and ketones?
A) Bromine water
B) Tollen’s reagent
C) Sodium hydroxide
D) Hydrochloric acid
Answer: B) Tollen’s reagent
Explanation: Aldehydes give silver mirror test with Tollen’s reagent; ketones do not.
73. The oxidation of formaldehyde produces:
A) Methanol
B) Formic acid
C) Acetic acid
D) Ethanol
Answer: B) Formic acid
Explanation: HCHO → HCOOH on oxidation.
74. Which functional group is present in soaps?
A) –CHO
B) –OH
C) –COOH (salt)
D) –NH₂
Answer: C) –COOH (salt)
Explanation: Soaps are sodium/potassium salts of long-chain carboxylic acids.
75. Esterification is the reaction between:
A) Alcohol and ketone
B) Alcohol and aldehyde
C) Alcohol and carboxylic acid
D) Aldehyde and acid
Answer: C) Alcohol and carboxylic acid
Explanation: Alcohol + Carboxylic acid → Ester + Water (with conc. H₂SO₄).
76. The chemical name of baking soda is:
A) Sodium carbonate
B) Sodium bicarbonate
C) Calcium carbonate
D) Sodium hydroxide
Answer: B) Sodium bicarbonate
Explanation: Baking soda = NaHCO₃.
77. The chemical name of washing soda is:
A) Sodium carbonate
B) Sodium bicarbonate
C) Sodium chloride
D) Calcium carbonate
Answer: A) Sodium carbonate
Explanation: Washing soda = Na₂CO₃·10H₂O.
78. Which gas is produced when vinegar reacts with baking soda?
A) O₂
B) H₂
C) CO₂
D) N₂
Answer: C) CO₂
Explanation: CH₃COOH + NaHCO₃ → CO₂ + H₂O + CH₃COONa.
79. Hard water does not lather easily with soap because it contains:
A) Na⁺ and K⁺ ions
B) Ca²⁺ and Mg²⁺ ions
C) Fe³⁺ ions
D) Cl⁻ ions
Answer: B) Ca²⁺ and Mg²⁺ ions
Explanation: These form insoluble salts with soap.
80. Detergents are effective even in hard water because they are:
A) Sodium salts of fatty acids
B) Ammonium or sulphonate salts
C) Simple hydrocarbons
D) Aldehydes
Answer: B) Ammonium or sulphonate salts
Explanation: Detergents do not form scum with Ca²⁺ and Mg²⁺.
81. The process of converting vegetable oils into fats is called:
A) Esterification
B) Hydrogenation
C) Polymerization
D) Saponification
Answer: B) Hydrogenation
Explanation: Addition of hydrogen to unsaturated oils using Ni catalyst makes them solid.
82. The process of making soap from oils/fats is called:
A) Esterification
B) Hydrogenation
C) Saponification
D) Cracking
Answer: C) Saponification
Explanation: Oils + NaOH → Soap + Glycerol.
83. Which polymer is known as “polythene”?
A) Polyvinyl chloride
B) Polyethylene
C) Polystyrene
D) Polypropylene
Answer: B) Polyethylene
Explanation: Polythene is made from polymerization of ethene.
84. Teflon is a polymer of:
A) Ethene
B) Tetrafluoroethene
C) Propene
D) Styrene
Answer: B) Tetrafluoroethene
Explanation: PTFE (Teflon) is made from CF₂=CF₂ monomers.
85. PVC stands for:
A) Polyvinyl chloride
B) Polyvinyl carbonate
C) Polyvinyl carbazole
D) Polyvinyl cyanide
Answer: A) Polyvinyl chloride
Explanation: PVC = (–CH₂–CHCl–)n.
86. Bakelite is a polymer of:
A) Phenol and methanal
B) Ethene and propene
C) Styrene and butadiene
D) Vinyl chloride and acrylonitrile
Answer: A) Phenol and methanal
Explanation: Bakelite is a condensation polymer used in electrical goods.
87. Nylon is a:
A) Natural polymer
B) Synthetic polymer
C) Semi-synthetic polymer
D) Inorganic polymer
Answer: B) Synthetic polymer
Explanation: Nylon is prepared from diamines and dicarboxylic acids.
88. Rayon is obtained from:
A) Cotton
B) Petroleum
C) Wood pulp
D) Coal tar
Answer: C) Wood pulp
Explanation: Rayon is a regenerated cellulose fiber.
89. Which is called artificial silk?
A) Nylon
B) Rayon
C) Polyester
D) Terylene
Answer: B) Rayon
Explanation: Rayon has silky texture, hence called artificial silk.
90. Which polymer is used in making non-stick cookware?
A) PVC
B) Polystyrene
C) Teflon
D) Nylon
Answer: C) Teflon
Explanation: PTFE (Teflon) is heat-resistant and non-stick.
91. Which of the following is a natural polymer?
A) Starch
B) PVC
C) Teflon
D) Polystyrene
Answer: A) Starch
Explanation: Starch, cellulose, proteins are natural polymers.
92. Which of the following is a biodegradable polymer?
A) Nylon
B) Polyester
C) Cellulose
D) Polythene
Answer: C) Cellulose
Explanation: Natural polymers are biodegradable, unlike synthetic plastics.
93. Which gas is commonly used in the ripening of fruits?
A) Ethane
B) Ethene
C) Ethyne
D) Methane
Answer: B) Ethene
Explanation: Ethene acts as a plant hormone for fruit ripening.
94. Which carbon compound is used as an anaesthetic?
A) Ethanol
B) Chloroform
C) Methane
D) Acetone
Answer: B) Chloroform
Explanation: Chloroform (CHCl₃) was used historically as an anaesthetic.
95. Which carbon compound is used as a solvent in nail polish removers?
A) Ethanol
B) Methanol
C) Acetone
D) Formaldehyde
Answer: C) Acetone
Explanation: Acetone (CH₃COCH₃) is a common organic solvent.
96. Which polymer is used in making bottles and carry bags?
A) PVC
B) Polythene
C) Nylon
D) Teflon
Answer: B) Polythene
Explanation: High/low-density polyethylene is used in bags and containers.
97. Which compound is called “antifreeze”?
A) Methanol
B) Ethanol
C) Ethylene glycol
D) Acetic acid
Answer: C) Ethylene glycol
Explanation: Ethylene glycol is added to car radiators to prevent freezing.
98. Which compound is commonly used as a preservative in pickles?
A) Acetic acid
B) Formaldehyde
C) Methanol
D) Ethanol
Answer: A) Acetic acid
Explanation: Vinegar (acetic acid) prevents microbial growth in pickles.
99. The compound used in preparation of sweeteners like aspartame is derived from:
A) Amino acids
B) Hydrocarbons
C) Aldehydes
D) Alcohols
Answer: A) Amino acids
Explanation: Aspartame is an artificial sweetener made from aspartic acid and phenylalanine.
100. Which of the following is a thermosetting plastic?
A) Polythene
B) PVC
C) Bakelite
D) Nylon
Answer: C) Bakelite
Explanation: Thermosetting plastics harden permanently on heating (Bakelite, melamine).