Chemistry is a core subject in Class 12 and plays a very important role in board examinations as well as competitive exams like JEE, NEET, CUET, and other entrance tests. Objective-type questions (MCQs) are especially useful for quick revision, concept clarity, and improving problem-solving speed.
This question set contains 75 carefully selected objective questions (MCQs) from the Class 12 Chemistry syllabus, covering Physical Chemistry, Organic Chemistry, and Inorganic Chemistry. Each question is provided with four multiple-choice options and the correct answer, making it ideal for self-practice, mock tests, and last-minute revision.
Class 12 Chemistry 75 Objective Questions with Answers
Q1. The rate of reaction depends on
A) Temperature only
B) Concentration only
C) Catalyst only
D) Concentration and temperature
Answer: D
Q2. Unit of rate constant for a first-order reaction is
A) mol L⁻¹ s⁻¹
B) s⁻¹
C) L mol⁻¹ s⁻¹
D) mol² L⁻² s⁻¹
Answer: B
Q3. pH of pure water at 25°C is
A) 0
B) 7
C) 14
D) 1
Answer: B
Q4. The value of Faraday constant is
A) 965 C
B) 9650 C
C) 96500 C
D) 96.5 C
Answer: C
Q5. Molality depends on
A) Temperature
B) Pressure
C) Mass of solvent
D) Volume of solution
Answer: C
Q6. Raoult’s law is applicable to
A) Ideal solutions
B) Colloids
C) Suspensions
D) Electrolytes
Answer: A
Q7. Depression in freezing point depends on
A) Nature of solute
B) Nature of solvent
C) Number of solute particles
D) Pressure
Answer: C
Q8. Osmotic pressure is measured by
A) Barometer
B) Manometer
C) Thermometer
D) Osmometer
Answer: D
Q9. Zero-order reaction has
A) Constant half-life
B) Rate independent of concentration
C) Rate proportional to concentration
D) High activation energy
Answer: B
Q10. Which is a strong electrolyte?
A) Glucose
B) Urea
C) NaCl
D) Sugar
Answer: C
Q11. pH of acidic solution is
A) < 7
B) = 7
C) > 7
D) = 14
Answer: A
Q12. Electrochemical cell converts
A) Electrical energy to chemical
B) Chemical energy to electrical
C) Heat to electrical
D) Mechanical to electrical
Answer: B
Q13. Standard electrode potential is measured at
A) 0°C
B) 25°C
C) 100°C
D) –273°C
Answer: B
Q14. The unit of conductivity is
A) Ohm
B) Ohm⁻¹ cm⁻¹
C) Volt
D) Ampere
Answer: B
Q15. Van’t Hoff factor is related to
A) Electrolysis
B) Colligative properties
C) Thermodynamics
D) Kinetics
Answer: B
Q16. Higher the activation energy,
A) Faster the reaction
B) Slower the reaction
C) No effect
D) Reaction stops
Answer: B
Q17. Which solution has maximum osmotic pressure?
A) 0.1 M glucose
B) 0.1 M NaCl
C) 0.1 M urea
D) Distilled water
Answer: B
Q18. Ideal solution shows
A) Volume change
B) Heat change
C) No deviation
D) Positive deviation
Answer: C
Q19. Which is a buffer solution?
A) NaCl + HCl
B) CH₃COOH + CH₃COONa
C) NaOH + HCl
D) NH₄Cl + NaOH
Answer: B
Q20. Half-life of zero-order reaction depends on
A) Concentration
B) Rate constant
C) Both A and B
D) Temperature only
Answer: C
Q21. Conductance increases with
A) Increase in dilution
B) Decrease in temperature
C) Decrease in ions
D) Increase in resistance
Answer: A
Q22. The unit of molar conductivity is
A) Ohm
B) Ohm cm
C) Ohm⁻¹ cm² mol⁻¹
D) Volt
Answer: C
Q23. Colligative properties depend on
A) Nature of solute
B) Nature of solvent
C) Number of particles
D) Pressure
Answer: C
Q24. Which is not a colligative property?
A) Osmotic pressure
B) Vapour pressure lowering
C) Freezing point depression
D) Surface tension
Answer: D
Q25. Arrhenius equation relates rate constant with
A) Temperature
B) Pressure
C) Volume
D) Density
Answer: A
Section B: Organic Chemistry (30 Questions)
Q26. Which group shows +I effect?
A) –NO₂
B) –CN
C) –CH₃
D) –COOH
Answer: C
Q27. Benzene mainly undergoes
A) Addition
B) Substitution
C) Elimination
D) Polymerization
Answer: B
Q28. Functional group of aldehyde is
A) –COOH
B) –CHO
C) –OH
D) –CO–
Answer: B
Q29. Tollen’s reagent is used to identify
A) Ketones
B) Aldehydes
C) Alcohols
D) Acids
Answer: B
Q30. Iodoform test is given by
A) Methanol
B) Ethanol
C) Propanol
D) Butanol
Answer: B
Q31. Primary alcohol on oxidation gives
A) Ketone
B) Aldehyde
C) Ester
D) Ether
Answer: B
Q32. Aniline is
A) Aliphatic amine
B) Aromatic amine
C) Secondary amine
D) Tertiary amine
Answer: B
Q33. Which is a reducing sugar?
A) Sucrose
B) Maltose
C) Cellulose
D) Starch
Answer: B
Q34. Nylon-6 is
A) Natural polymer
B) Addition polymer
C) Condensation polymer
D) Copolymer
Answer: C
Q35. Monomer of PVC is
A) Ethene
B) Vinyl chloride
C) Styrene
D) Acetylene
Answer: B
Q36. Phenol is acidic due to
A) Inductive effect
B) Resonance stabilization
C) Hyperconjugation
D) Steric effect
Answer: B
Q37. Which alcohol gives Lucas test immediately?
A) Primary
B) Secondary
C) Tertiary
D) All
Answer: C
Q38. Acetic acid belongs to
A) Aldehydes
B) Ketones
C) Carboxylic acids
D) Esters
Answer: C
Q39. The functional group in ester is
A) –COOH
B) –COOR
C) –CHO
D) –OH
Answer: B
Q40. Which compound is aromatic?
A) Cyclohexane
B) Benzene
C) Ethene
D) Propene
Answer: B
Q41. SN1 reaction proceeds via
A) Free radical
B) Carbocation
C) Carbanion
D) Transition complex
Answer: B
Q42. SN2 reaction is
A) Two-step
B) One-step
C) Slow
D) Unimolecular
Answer: B
Q43. Which polymer is biodegradable?
A) PVC
B) Nylon
C) PHBV
D) Polythene
Answer: C
Q44. Glucose is
A) Ketose
B) Aldose
C) Disaccharide
D) Polysaccharide
Answer: B
Q45. Which vitamin is water soluble?
A) Vitamin A
B) Vitamin D
C) Vitamin C
D) Vitamin K
Answer: C
Q46. Soap is
A) Sodium salt of fatty acid
B) Potassium salt of alcohol
C) Ester
D) Acid
Answer: A
Q47. Detergents are
A) Biodegradable
B) Non-biodegradable
C) Proteins
D) Enzymes
Answer: B
Q48. Which compound gives silver mirror test?
A) Acetone
B) Formaldehyde
C) Ethanol
D) Acetic acid
Answer: B
Q49. Carbohydrates contain
A) C, H only
B) C, H, O
C) C, O only
D) C, N, O
Answer: B
Q50. DNA is a
A) Protein
B) Carbohydrate
C) Lipid
D) Nucleic acid
Answer: D
Q51. Which is a secondary alcohol?
A) Methanol
B) Ethanol
C) Isopropyl alcohol
D) Tert-butanol
Answer: C
Q52. Which compound is used as anesthetic?
A) Chloroform
B) Methane
C) Ethanol
D) Ethene
Answer: A
Q53. Amines are derivatives of
A) Ammonia
B) Water
C) Alcohol
D) Ether
Answer: A
Q54. Which is an example of copolymer?
A) PVC
B) Nylon-6
C) Buna-S
D) Polythene
Answer: C
Q55. Which sugar is non-reducing?
A) Glucose
B) Fructose
C) Maltose
D) Sucrose
Answer: D
Section C: Inorganic Chemistry (20 Questions)
Q56. Which is a transition element?
A) Na
B) Mg
C) Fe
D) Al
Answer: C
Q57. Lanthanides show
A) Increasing size
B) Lanthanide contraction
C) No oxidation state
D) Low density
Answer: B
Q58. Which oxide is acidic?
A) Na₂O
B) MgO
C) Al₂O₃
D) CO₂
Answer: D
Q59. Most electronegative element is
A) Oxygen
B) Chlorine
C) Fluorine
D) Nitrogen
Answer: C
Q60. Rusting of iron is
A) Oxidation
B) Reduction
C) Redox reaction
D) Neutralization
Answer: C
Q61. Coordination number of [Fe(CN)₆]³⁻ is
A) 3
B) 4
C) 6
D) 8
Answer: C
Q62. Acid rain is caused by
A) CO₂
B) SO₂
C) O₂
D) N₂
Answer: B
Q63. Bleaching powder acts as
A) Reducing agent
B) Oxidizing agent
C) Acid
D) Base
Answer: B
Q64. Oxidation state of Mn in KMnO₄ is
A) +2
B) +4
C) +6
D) +7
Answer: D
Q65. Aluminium is extracted by
A) Roasting
B) Calcination
C) Electrolysis
D) Reduction
Answer: C
Q66. Which metal shows variable oxidation state?
A) Na
B) K
C) Fe
D) Ca
Answer: C
Q67. Which gas is used in welding?
A) Oxygen
B) Nitrogen
C) Acetylene
D) Hydrogen
Answer: C
Q68. Hardness of water is due to
A) Na⁺ ions
B) Ca²⁺ and Mg²⁺ ions
C) K⁺ ions
D) H⁺ ions
Answer: B
Q69. Which is a noble gas?
A) Oxygen
B) Nitrogen
C) Helium
D) Hydrogen
Answer: C
Q70. Which halogen is most reactive?
A) Chlorine
B) Bromine
C) Iodine
D) Fluorine
Answer: D
Q71. Which compound is amphoteric?
A) NaOH
B) HCl
C) Al₂O₃
D) CO₂
Answer: C
Q72. Which metal is liquid at room temperature?
A) Iron
B) Mercury
C) Copper
D) Aluminium
Answer: B
Q73. Which element is used in nuclear reactor?
A) Uranium
B) Iron
C) Copper
D) Zinc
Answer: A
Q74. Which compound is basic oxide?
A) CO₂
B) SO₂
C) Na₂O
D) Al₂O₃
Answer: C
Q75. Which salt is used in photography?
A) NaCl
B) KCl
C) AgBr
D) CuSO₄
Answer: C
FAQs –Class 12 Chemistry 75 Objective
### Q1. Are these 75 objective questions based on the NCERT Class 12 Chemistry syllabus?
Yes, all the 75 objective questions are strictly based on the NCERT Class 12 Chemistry syllabus. The questions cover important concepts from Physical, Organic, and Inorganic Chemistry that are frequently asked in board exams and competitive examinations.
### Q2. Are these MCQs useful for board exams as well as competitive exams?
Absolutely. These MCQs are useful for Class 12 Board Exams, and also help in preparation for CUET, JEE (Main), NEET, and other entrance exams as they focus on conceptual clarity and exam-oriented practice.
### Q3. Do these questions include answers for self-practice?
Yes, each objective question is provided with four multiple-choice options along with the correct answer, making it easy for students to practice independently and quickly evaluate their performance.
### Q4. How should students use these 75 MCQs for effective revision?
Students should first attempt all the questions without looking at the answers, then check the answer key, and revise weak topics from NCERT textbooks. Practicing these MCQs regularly will improve speed, accuracy, and confidence.
### Q5. Are these MCQs suitable for last-minute exam revision?
Yes, these MCQs are highly suitable for last-minute revision. They help students quickly recall important concepts, formulas, reactions, and facts just before the exam.
Conclusion-Class 12 Chemistry 75 Objective
Objective-type questions play a crucial role in scoring well in Class 12 Chemistry examinations. This collection of 75 MCQs with answers provides a balanced coverage of Physical, Organic, and Inorganic Chemistry, helping students strengthen their conceptual understanding and exam readiness.
By practicing these questions regularly, students can improve their problem-solving skills, manage time effectively during exams, and boost their overall confidence. This MCQ set is an excellent resource for board exam preparation, competitive exams, and quick revision, making it a must-have study material for every Class 12 Chemistry student.