CBSE Class 12 Chemistry Exam 2025 Tomorrow: Top 50 MCQs with Answers for High Score in Exam!

CBSE Class 12th Chemistry Important MCQs: The CBSE Class 12th Chemistry Board Exam 2025 requires thorough practice, especially with Multiple-Choice Questions (MCQs), which play a key role in scoring well. To help students prepare efficiently, we have compiled the top 50 MCQs from previous years' question papers and CBSE sample papers, along with detailed answers. These important MCQs cover essential topics from all the chapters, ensuring a strong revision before the exam. Solve these high-weightage questions to boost your confidence and improve your exam performance.

CBSE Class 12th Chemistry Paper: Key Highlights

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CBSE Class 12th Chemistry Exam Top 50 MCQs with Answers

Here are 50 important multiple-choice questions (MCQs) from all chapters in your 12th Chemistry syllabus along with their answers:  

1. Which of the following is a colligative property?

a) Surface tension  

b) Osmotic pressure  

c) Viscosity  

d) Density  

Ans: (b) Osmotic pressure  

2. What is the unit of molality? 

a) mol/L  

b) mol/kg  

c) g/L  

d) kg/mol  

Ans:(b) mol/kg  

3. 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  

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

a) Positive  

b) Negative  

c) No deviation  

d) None of these  

Ans: a) Positive

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. 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  

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:  

a) Alcohols  

b) Ketones  

c) Carboxylic acids  

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?  

a) LiAlH₄  

b) Zn/HCl  

c) K₂Cr₂O₇  

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)  

That completes the 50 most important MCQs from all chapters in Class 12th Chemistry

Other Related Links

• NCERT Class 12th Revised Textbooks 2025

• NCERT Class 12th Solutions 2025

• CBSE Class 12th Sample Papers