CBSE Class 12 Chemistry MCQs 2025: 50 Important Questions with Answer

CBSE Class 12th Chemistry Exam 2025: The CBSE Class 12th Chemistry exam is scheduled on 27th February 2025. Important 50 MCQs are here. Students should solve all the important MCQs to score high marks in the exam.

CBSE Class 12th Chemistry Important MCQs: The CBSE Class 12th Chemistry board exam 2025 requires intensive practice, especially with multiple-choice questions (MCQs), which are crucial in scoring good marks. To help students prepare efficiently, we have compiled the top 50 MCQs from previous years question papers and CBSE sample papers with detailed answers. These important MCQs cover essential topics from all chapters, ensuring a strong revision before the exam. Solve these high-importance questions to boost your confidence and perform better on the exam.

CBSE Class 12th Chemistry Paper: Key Highlights

Particulars	Details
Exam Conducting Body	Central Board of Secondary Education (CBSE)
Subject	Chemistry
Mode of Exam	Offline
Exam Duration	3 Hours
Medium of Exam	English / Hindi
Type of Questions	MCQs, Short and Long Answer Type Questions
Theory Marks	80
Internal Assessment	20
Total Marks	100
Passing Marks	33% in aggregate

CBSE Class 12th Chemistry Exam Top 50 MCQs with Answers

Here are 50 important Multiple Choice Questions (MCQs) along with their answers from all chapters of your 12th Chemistry syllabus:

1. Which of the following is a colligative property?

a) Surface tension

b) Osmotic pressure

c) Viscosity

d) Density

Ans: (b) Osmotic pressure

2. Which law governs the solubility of gases in liquids?

a) Henry’s law

b) Raoult’s law

c) Dalton’s law

d) Boyle’s law

Ans: (a) Henry’s law

3. What is the unit of molality? 

a) mol/L

b) mol/kg

c) g/L

d) kg/mol

Ans:(b) mol/kg

4. Which type of deviation is shown by ethanol and water mixture?

a) Positive

b) Negative

c) No deviation

d) None of these

Ans: (b) Negative 

5. Van’t Hoff factor (i) for K₂SO₄ in water is: 

a) 1

b) 2

c) 3

d) 4

Ans: (c) 3

6. Which of the following statements is true for a galvanic cell?

a) Oxidation occurs at the cathode

b) Reduction occurs at the anode

c) Electrons flow from the anode to the cathode

d) Anode is positive

Ans: (c) Electrons flow from anode to cathode

7. What is the standard electrode potential of the hydrogen electrode?

a) 0.00 V

b) 1.00 V

c) -0.76 V

d) 0.34 V

Ans: (a) 0.00 V

8. Which electrolyte is used in a dry cell?

a) H₂SO₄

b) KOH

c) NH₄Cl

d) NaOH

Ans: (c) NH₄Cl

9. Which of the following is a primary cell?

a) Lead storage battery

b) Fuel cell

c) Dry cell

d) Nickel-cadmium cell

Ans: (c) Dry cell

10. Which law is used to determine the mass of a substance deposited during electrolysis?

a) Henry’s law

b) Faraday’s law

c) Raoult’s law

d) Nernst equation

Ans: (b) Faraday’s law

11. The rate of reaction is affected by: 

a) Temperature

b) Concentration

c) Catalyst

d) All of these

Ans: (d) All of these

12. What is the unit of rate constant for a first-order reaction?

a) s⁻¹

b) mol L⁻¹ s⁻¹

c) L mol⁻¹ s⁻¹

d) L² mol⁻² s⁻¹

Ans: (a) s⁻¹

13. The half-life of a first-order reaction is:

a) Proportional to initial concentration

b) Independent of initial concentration

c) Inversely proportional to initial concentration

d) Depends on pressure

Ans: (b) Independent of initial concentration

14. The Arrhenius equation represents the effect of ______ on reaction rate.

a) Catalyst

b) Temperature

c) Pressure

d) Concentration

Ans: (b) Temperature

15. Activation energy is the:

a) Minimum energy required for a reaction to occur

b) Maximum energy required for a reaction

c) Energy of the reactants

d) Energy of the products

Ans: (a) Minimum energy required for a reaction to occur

16. Which element is not a transition metal?

a) Fe

b) Zn

c) Cr

d) Mn

Ans: (b) Zn

17. KMnO₄ is used as:

a) Reducing agent

b) Oxidizing agent

c) Both

d) None

Ans: (b) Oxidizing agent

18. Lanthanide contraction is due to:

a) Poor shielding by 4f electrons

b) High nuclear charge

c) Both (a) and (b)

d) None of these

Ans: (c) Both (a) and (b)

19. Which of the following is a radioactive element?

a) Ce

b) U

c) La

d) Y

Ans: (b) U

20. Which of the following is a transition element?

a) Ca

b) Sc

c) Na

d) K

Ans: (b) Sc

21. Which of the following is a chelating ligand?

a) CN⁻

b) EDTA

c) NH₃

d) Cl⁻ 

Ans: (b) EDTA

22. Which theory explains the colour and magnetic properties of coordination compounds?

a) VBT

b) Crystal field theory

c) Molecular orbital theory

d) Band Theory

Ans: (b) Crystal field theory

23. Oxidation state of Co in [Co(NH₃)₆]³⁺ is:

a) +1

b) +2

c) +3

d) 0

Ans: (c) +3

24. Which is a bidentate ligand?

a) NH₃

b) C₂O₄²⁻

c) CN⁻

d) Cl⁻

Ans: (b) C₂O₄²⁻

25. Which ligand causes the highest crystal field splitting?

a) CN⁻

b) Cl⁻

c) H₂O

d) OH⁻

Ans: (a) CN⁻ 

26. Which of the following will undergo SN1 reaction most easily?

a) CH₃Cl

b) (CH₃)₃CBr

c) CH₃CH₂Br

d) CH₃CH₂Cl

Ans: (b) (CH₃)₃CBr

27. Which of the following is used as an anaesthetic?

a) CHCl₃

b) CCl₄

c) CH₂Cl₂

d) CF₂Cl₂

Ans: (a) CHCl₃ 

28. Which of the following undergoes nucleophilic substitution reaction most easily?

a) Benzyl chloride

b) Vinyl chloride

c) Chloroethane

28. d) Chlorobenzene

Ans: (a) Benzyl chloride

29. Freons are mainly used as:

a) Antiseptics

b) Refrigerants

c) Fertilizers

d) Medicines

Ans: (b) Refrigerants

30. DDT is a:

a) Polymer

b) Pesticide

c) Antibiotic

d) Fuel

Ans: (b) Pesticide

   31. Phenol is more acidic than ethanol because:

a) Phenoxide ion is resonance stabilized

b) Ethoxide ion is resonance stabilized

c) Both are equally acidic

d) Phenol does not release H⁺ ions

Ans: (a) Phenoxide ion is resonance stabilized

32. Which reagent is used to distinguish between alcohols and phenols?

a) Fehling’s solution

b) Iodoform test

c) Neutral FeCl₃

d) Lucas reagent

Ans: (c) Neutral FeCl₃

33. Which compound is commonly known as wood spirit?

a) Ethanol

b) Methanol

c) Phenol

d) Glycerol

Ans: (b) Methanol

34. Ethers can be cleaved by:

a) Dilute H₂SO₄

b) Conc. HBr

c) NaOH

d) KMnO₄

Ans: (b) Conc. HBr

35. Which of the following is used as an antiseptic?

a) Benzene

b) Phenol

c) Ethanol

d) Ether

Ans: (b) Phenol

36. Which test is used to distinguish between aldehydes and ketones?

a) Lucas test

b) Tollens’ test

c) Fehling’s test

d) Both (b) and (c)

Ans: (d) Both (b) and (c)

37. Which of the following undergoes the iodoform test?

a) Benzaldehyde

b) Acetone

c) Formaldehyde

d) Ethanol

Ans: (b) Acetone

38. Which of the following has the highest boiling point?

a) Alcohol

b) Aldehyde

c) Ketone

d) Ether

Ans: (a) Alcohol

39. What is the functional group of carboxylic acids?

a) –OH

b) –COOH

c) –CHO

d) –CO–

Ans: (b) –COOH

40. The reduction of aldehydes leads to the formation of:
41. a) Alcohols
42. b) Ketones
43. c) Carboxylic acids
44. d) Esters

Ans: (a) Alcohols

41. Which amine reacts with Hinsberg reagent to form a soluble product?

a) Primary amine

b) Secondary amine

c) Tertiary amine

d) Quaternary ammonium salt

Ans: (a) Primary amine

42.Which reagent is used to convert nitrobenzene into aniline?

1. a) LiAlH₄
2. b) Zn/HCl
3. c) K₂Cr₂O₇
4. d) NaOH

Ans: (b) Zn/HCl

43. Which of the following amines is most basic?

a) NH₃

b) CH₃NH₂

c) C₆H₅NH₂

d) (C₂H₅)₂NH

Ans: (d) (C₂H₅)₂NH

44. What is the product of the reaction between aniline and bromine water?

a) o-Bromoaniline

b) p-Bromoaniline

c) 2,4,6-Tribromoaniline

d) Aniline does not react with bromine water

Ans: (c) 2,4,6-Tribromoaniline

45. Which of the following is a secondary amine?

a) NH₃

b) CH₃NH₂

c) (CH₃)₂NH

d) (CH₃)₃N

Ans: (c) (CH₃)₂NH 

46. Glucose is an example of:

a) Disaccharide

b) Monosaccharide

c) Polysaccharide

d) Protein

Ans: (b) Monosaccharide

47. Which of the following is NOT a polysaccharide?

a) Starch

b) Glycogen

c) Cellulose

d) Sucrose

Ans: (d) Sucrose

48. The bond between two amino acids in a protein is called:

a) Glycosidic bond

b) Peptide bond

c) Phosphodiester bond

d) Hydrogen bond

Ans: (b) Peptide bond

49. Which of the following is an essential amino acid?

a) Glycine

b) Alanine

c) Lysine

d) Proline

Ans: (c) Lysine

50. Which nucleic acid is responsible for protein synthesis?

a) DNA

b) tRNA

c) rRNA

d) Both (b) and (c)

Ans: (d) Both (b) and (c)