CBSE Class 12 Chemistry Question Paper 2025 (Set 1 - 56/6/1) with Solutions is now available here for download. CBSE conducted the Class 12 Chemistry examination on February 27, 2025, from 10:30 AM to 1:30 PM.

CBSE Class 12 Chemistry paper is of total 100 marks out of which 70 marks are allocated to the theory paper and 30 marks are for practical examination.

Also Check: CBSE Class 12 Question Paper 2025 (All Subjects)

The theory paper consists of 33 questions divided into five sections:

  • Section A contains Multiple Choice Questions (MCQs),
  • Section B contains Very Short Answer Type (VSA) Questions,
  • Section C contains Short Answer Type (SA) Questions,
  • Section D contains Case-Study based Questions,
  • Section E contains Long Answer (LA) Type Questions.

All sections are compulsory.

CBSE Class 12 Chemistry Question Paper 2025 (Set 1 - 56/6/1) with Solution PDF

CBSE Class 12 Chemistry 2025 Set 1 (56/6/1) Questions with Solutions

Question 1:

Williamson synthesis of preparing unsymmetrical ether is :

  • (A) SN1 reaction
  • (B) SN2 reaction
  • (C) Electrophilic addition reaction
  • (D) Elimination reaction

Question 2:

Which of the following compounds would be hydrolysed by aqueous KOH most easily ?

  • (A) CH2=CH-Br
  • (B) CH3-CH2-Br
  • (C) CH3-CHBr-CH3
  • (D) CH2=CH-CH2-Br

Question 3:

According to Werner's theory of coordination compounds :

  • (A) Primary valences are ionisable.
  • (B) Secondary valences are ionisable.
  • (C) Both primary and secondary valences are non-ionisable.
  • (D) Both primary and secondary valences are ionisable.

Question 4:

Which of the following complex ion is not optically active ?

  • (A) [Co(ox)3]3-
  • (B) cis-[Co(en)2Cl2]+
  • (C) trans-[Co(en)2Cl2]+
  • (D) [Co(en)3]3+

Question 5:

Which of the following is the softest metal ?

  • (A) Zn
  • (B) Sc
  • (C) Cu
  • (D) Fe

Question 6:

In the Hinsberg method for separation of primary, secondary, and tertiary amines, the reagent used is:

  • (A) Nitrous acid
  • (B) CHCl₃ + aq. NaOH
  • (C) \(\text{C}_6\text{H}_5\text{SO}_2\text{Cl}\)
  • (D) HCl / ZnCl₂

Question 7:

Which one of the following amines gives an alcohol on reaction with HNO₂?

  • (A) \(\text{NH}_2\)
  • (B) \(\text{C}_2\text{H}_5\text{NH}_2\)
  • (C) \(\text{C}_2\text{H}_5\text{N}\text{H}_2\)
  • (D) \(\text{C}_2\text{H}_5\text{N}_3\)

Question 8:

The freezing point of one molal KCl solution, assuming KCl to be completely dissociated in water, is: (\(K_f\) for water = 1.86 K kg mol\(^{-1}\))

  • (A) \(-3.72^\circ C\)
  • (B) \(+3.72^\circ C\)
  • (C) \(-1.86^\circ C\)
  • (D) \(+2.72^\circ C\)

Question 9:

A solution of acetone in ethanol :

  • (A) obeys Raoult's law.
  • (B) forms an ideal solution.
  • (C) shows a positive deviation from Raoult's law.
  • (D) shows a negative deviation from Raoult's law.

Question 10:

Which of the following cell converts the energy of combustion of fuel into electrical energy ?

  • (A) Mercury cell
  • (B) Fuel cell
  • (C) Dry cell
  • (D) Lead storage cell

Question 11:

The unit of rate and rate constant are same for a :

  • (A) First order reaction
  • (B) Second order reaction
  • (C) Zero order reaction
  • (D) Third order reaction

Question 12:

Pyranose ring of glucose is formed due to the reaction between :

  • (A) C1 and C3
  • (B) C1 and C6
  • (C) C1 and C4
  • (D) C1 and C5

Question 13:

Assertion (A) : Actinoids show wide range of oxidation states.

Reason (R) : Actinoids are radioactive in nature.

  • (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
  • (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
  • (C) Assertion (A) is true, but Reason (R) is false.
  • (D) Assertion (A) is false, but Reason (R) is true.

Question 14:

Assertion (A) : Hydrolysis of an ester follows first order kinetics.

Reason (R) : The concentration of water does not get altered much during the reaction.

  • (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
  • (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
  • (C) Assertion (A) is true, but Reason (R) is false.
  • (D) Assertion (A) is false, but Reason (R) is true.

Question 15:

Assertion (A) : Boiling point of (CH3)3N is higher than that of CH3CH2CH2NH2.

Reason (R) : Hydrogen bonding is more extensive in CH3CH2CH2NH2.

  • (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
  • (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
  • (C) Assertion (A) is true, but Reason (R) is false.
  • (D) Assertion (A) is false, but Reason (R) is true.

Question 16:

Assertion (A) : Phenol is strongly acidic as compared to ethanol.

Reason (R) : Phenoxide ion is more stable than ethoxide ion.

  • (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
  • (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
  • (C) Assertion (A) is true, but Reason (R) is false.
  • (D) Assertion (A) is false, but Reason (R) is true.

Question 17:

State Henry's law. Why are aquatic species more comfortable in cold water as compared to warm water ?


Question 18:

Observe the graph in the given figure and answer the following questions :

(a) Predict the order of reaction.

(b) What is the slope of the curve ?


Question 19(a)(i):

Write IUPAC names of the following coordination compounds :

[CoCl2(en)2]SO4


Question 19(a)(ii):

Write IUPAC names of the following coordination compounds :

K3[Fe(C2O4)3]


Question 19(b)(i) (OR):

Differentiate between:
(i) Double salt and Complex compound
(ii) Didentate ligand and Ambidentate ligand


Question 19(b)(ii) (OR):

Differentiate between:
(i) Double salt and Complex compound
(ii) Didentate ligand and Ambidentate ligand


Question 20:

Draw the structures of major monohalo products in each of the following reactions :

(a)

(b)


Question 21:

How do you explain the following ?

(a) Presence of an aldehydic group in glucose.

(b) Presence of five -OH groups in glucose.


Question 22:

Vapour pressure of pure water at 298 K is 24.8 mm Hg. Calculate the lowering in vapour pressure of an aqueous solution which freezes at -0.3°C. (Kf of water = 1.86 K kg mol-1)


Question 23:

The rate of a reaction:
A + B \(\to\) product
is given below as a function of different initial concentrations of A and B.

Experiment\([A]\) / mol L\(^{-1}\)\([B]\) / mol L\(^{-1}\)Initial Rate / mol L\(^{-1}\) min\(^{-1}\)
10.010.01\(5 \times 10^{-3}\)
20.020.01\(1 \times 10^{-2}\)
30.010.02\(5 \times 10^{-3}\)

Calculate the order of the reaction with respect to A and B. Determine the rate constant of the reaction.


Question 24:

Give reasons for the following :

(a) The pH of aqueous NaCl increases when it is electrolysed.

(b) Unlike dry cell, mercury cell has a constant cell potential through its lifetime.

(c) Conductivity of solution decreases with dilution.


Question 25(a)(i):

Answer the following about the complexes \([ \text{FeF}_6]^{3-} \text{ and } [\text{Fe(CN)}_6]^{4-}\):
(i) Write the hybridization involved in each case.
(ii) Which of them is the outer orbital complex and which one is the inner orbital complex?
(iii) Compare their magnetic behaviour.
[Atomic number: Fe = 26]


Question 25(a)(ii):

Answer the following about the complexes \([ \text{FeF}_6]^{3-} \text{ and } [\text{Fe(CN)}_6]^{4-}\):
(i) Write the hybridization involved in each case.
(ii) Which of them is the outer orbital complex and which one is the inner orbital complex?
(iii) Compare their magnetic behaviour.
[Atomic number: Fe = 26]


Question 25(a)(iii):

Answer the following about the complexes \([ \text{FeF}_6]^{3-} \text{ and } [\text{Fe(CN)}_6]^{4-}\):
(i) Write the hybridization involved in each case.
(ii) Which of them is the outer orbital complex and which one is the inner orbital complex?
(iii) Compare their magnetic behaviour.
[Atomic number: Fe = 26]


Question 25(b)(i) (OR):

What happens to the colour of complex [Ti(H2O)6]3+ when heated gradually ?


Question 25(b)(ii) (OR):

On the basis of crystal field theory, write the electronic configuration for \(d^5\) ion for which \(\Delta_o \lt P\)


Question 25(b)(iii) (OR):

Write the hybridization and magnetic character of the complex \([Ni(CO)_4]\) on the basis of valence bond theory.
[Atomic No. Ni = 28]


Question 26:

Write any two differences between SN1 and SN2 reactions. Which of the following compounds would undergo SN1 reaction faster and why ?


Question 27:

A compound (A) with molecular formula C4H5N on reduction with DIBAL-H followed by hydrolysis, gives a compound (B). Compound (B) gives positive Tollens' test but does not give iodoform test. Compound (B) can also be obtained when ethanal is treated with dilute NaOH followed by heating. Identify (A) and (B). Write the reactions of (A) with DIBAL-H followed by hydrolysis.


Question 28:

How will you obtain the following from aniline ? Give chemical equations only.

(a) Sulphanilic acid

(b) Phenylisocyanide

(c) Acetanilide


Question 29(a):

Case-based: Alcohols undergo a number of reactions involving the cleavage of C - OH bond. However, phenols do not undergo reactions involving the cleavage of C - OH bond. Alcohols are weaker acids than water. Alcohols react with halogen acids to form the corresponding haloalkanes. Phenols are stronger acids than alcohols. A characteristic feature of phenols is that they undergo electrophilic substitution reactions such as halogenation, nitration, etc. Since -OH group is a strong activating group, phenol gives trisubstituted products during halogenation, nitration, etc.

What happens when phenol is treated with the following ? [2]

(i) Br2 water (ii) Conc. HNO3


Question 29(b):

Write the mechanism of alcohol reacting as nucleophile in a reaction with CH3+. [1]


Question 29(b) (OR):

Why do phenols not undergo reactions involving cleavage of C - OH bond ? [1]


Question 29(c):

How can you distinguish between Butan-1-ol and 2-Methylpropan-2-ol by using HCl in the presence of anhydrous ZnCl2 ? [1]


Question 30(a):

Case-based: The α-amino acids are the building blocks of proteins. All α-amino acids exist as zwitter ion due to which they show amphoteric behaviour. All amino acids are joined through peptide bond. Proteins are broadly classified as globular proteins and fibrous proteins. Globular proteins are water soluble, whereas fibrous proteins are not. The complete structure of protein is discussed at four different levels i.e. primary, secondary, tertiary and quaternary structures. Protein loses its biological activity in denatured form.

Define the following : [2]

(i) Peptide linkage (ii) Denatured protein


Question 30(b):

Why do amino acids show amphoteric behaviour ? [1]


Question 30(c):

How can you differentiate between Fibrous protein and Globular protein ? [1]


Question 30(c) (OR):

(c) (ii) Write the names of two different secondary structures of proteins. [1]


Question 31(a)(i):

Calculate \( E_{\text{cell}} \) of a galvanic cell in which the following reaction takes place at 25°C:
\[ \text{Zn(s)} + \text{Pb}^{2+}(0.02M) \longrightarrow \text{Zn}^{2+}(0.1M) + \text{Pb(s)} \quad \text{[Given: } E^0_{\text{Zn}^{2+}/\text{Zn}} = -0.76V, \; E^0_{\text{Pb}^{2+}/\text{Pb}} = -0.13V, \; \log 2 = 0.3010, \; \log 4 = 0.6021, \; \log 5 = 0.6990 \text{]} \]


Question 31(a)(ii):

State Faraday's first law of electrolysis. How much electricity, in terms of Faraday, is required to reduce one mol of MnO4- to Mn2+ ion ?


Question 31(b)(i) (OR):

The resistance of a conductivity cell containing 0.001 M KCl solution at 298 K is 1000 ohm. What is the cell constant if conductivity of 0.001 M KCl solution at 298 K is 0.125 × 10-2 S cm-1 ?


Question 31(b)(ii) (OR):

Calculate the \( E_{Mg^{2+}/Mg} \) potential for the following half cell at 25°C :

Mg/Mg2+(1 × 10−4 M); E°Mg2+/Mg = +2.36 V

[Given : log 10 = 1]


Question 31(b)(iii) (OR):

What is the effect of temperature on the electrical conductance of metallic conductor ?


Question 32(a)(i):

Account for the following :

(I) Orange colour of Cr2O72- ion changes to yellow when treated with an alkali.

(II) Zn, Cd and Hg are non-transition elements.

(III) E° value for Mn3+/Mn2+ couple is highly positive (+1.57 V) as compared to Cr3+/Cr2+.


Question 32(a)(ii):

What happens when :

(I) Manganate ion undergoes disproportionation reaction in acidic medium ?

(II) KMnO4 is heated ?


Question 32(b)(i) (OR):

What is 'Misch metal' ? Give its one use.


Question 32(b)(ii) (OR):

Write the formula of an oxoanion of chromium in which it shows the oxidation state equal to its group number.


Question 32(b)(iii) (OR):

Why does Vanadium pentoxide (V2O5) act as a catalyst ?


Question 32(b)(iv) (OR):

Why do transition elements have high enthalpies of atomisation ?


Question 32(b)(v) (OR):

How do you prepare Na2Cr2O7 from Na2CrO4 ?


Question 33(a)(i):

Identify A, B and C in the following reactions :


Question 33(a)(ii):

Give reasons for the following :

(I) Carboxylic acids do not give the characteristic reactions of carbonyl group.

(II) Ethanoic acid is a stronger acid than ethanol.


Question 33(b)(i) (OR):

Write the product(s) in the following reactions:

dehydration of acetic acid with phosphorus pentoxide


Question 33(b)(ii) (OR):

Write the reaction involved in the following reactions :
(I) Wolff-Kishner Reduction
(II) Decarboxylation Reaction

CBSE Class 12 Chemistry Question Paper Pattern 2025

The CBSE Class 12 Chemistry 2025 question paper is of 70 marks and has 33 questions in five sections, A to E, all compulsory, with internal choice in some questions of Sections B to E. The time allowed is 3 hours, with 15 minutes of extra reading time. The table below gives the section-wise paper pattern from the official CBSE question paper.

Section Questions Question Type Marks per Question Marks
A Q1 - Q16 Multiple choice questions 1 16
B Q17 - Q21 Very short answer questions 2 10
C Q22 - Q28 Short answer questions 3 21
D Q29 - Q30 Case study-based questions 4 8
E Q31 - Q33 Long answer questions 5 15
Total 33 questions 70

CBSE Class 12 Chemistry Unit-Wise Weightage

Unit No. Unit Name Marks
1 Solutions 7
2 Electrochemistry 9
3 Chemical Kinetics 7
4 d- and f-Block Elements 7
5 Coordination Compounds 7
6 Haloalkanes and Haloarenes 6
7 Alcohols, Phenols and Ethers 6
8 Aldehydes, Ketones and Carboxylic Acids 8
9 Amines 6
10 Biomolecules 7
Total — 70