CBSE Class 12 Chemistry Set 1 (56/2/1) Question Paper 2025

Q: How many questions are there in the CBSE Class 12 Chemistry 2025 Set 1 (56/2/1) question paper?

The paper has 33 questions in five sections (A to E) for 70 marks: 16 MCQs of 1 mark, 5 very short answer questions of 2 marks, 7 short answer questions of 3 marks, 2 case-study questions of 4 marks and 3 long answer questions of 5 marks.

Q: How much time do you get for the CBSE Class 12 Chemistry 2025 paper?

The paper is of 3 hours (10:30 AM to 1:30 PM). The question paper is handed out at 10:15 AM, and you get 15 minutes to read it before writing starts at 10:30 AM.

CBSE Class 12 Chemistry Question Paper 2025 (Set 1 - 56/2/1) 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 Set 1 (56/2/1) theory paper consists of 33 questions divided into five sections:

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

All questions are compulsory. There is no overall choice, but some questions in Sections B to E carry an internal choice.

CBSE Class 12 Chemistry Question Paper 2025 (Set 1 - 56/2/1) with Solution PDF

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CBSE Class 12 Chemistry 2025 Set 1 (56/2/1) Questions with Solutions

Question 1:

The charge required for the reduction of 1 mol of MnO₄^- to MnO₂ is

(A) 1F
(B) 3F
(C) 5F
(D) 6F

Detailed Solution

Question 2:

Which among the following is a false statement?

(A) Rate of zero order reaction is independent of initial concentration of reactant.
(B) Half-life of a zero order reaction is inversely proportional to the rate constant.
(C) Molecularity of a reaction may be zero.
(D) For a first order reaction, t_1/2 = 0.693/k.

Detailed Solution

Question 3:

The number of molecules that react with each other in an elementary reaction is a measure of the:

(A) activation energy of the reaction
(B) stoichiometry of the reaction
(C) molecularity of the reaction
(D) order of the reaction

Detailed Solution

Question 4:

The element having [Ar]3d¹⁰4s¹ electronic configuration is

(A) Cu
(B) Zn
(C) Cr
(D) Mn

Detailed Solution

Question 5:

The complex ions [Co(NH₃)₅(NO₂)]²⁺ and [Co(NH₃)₅(ONO)]²⁺ are called

(A) Ionization isomers
(B) Linkage isomers
(C) Co-ordination isomers
(D) Geometrical isomers

Detailed Solution

Question 6:

The diamagnetic species is: [At. No. Co = 27, Fe = 26, Ni = 28]

(A) [Ni(CN)₄]^2-
(B) [NiCl₄]^2-
(C) [Fe(CN)₆]^3-
(D) [CoF₆]^3-

Detailed Solution

Question 7:

Which is the correct IUPAC name for

(A) Methylchlorobenzene
(B) Toluene
(C) 1-Chloro-4-Methylbenzene
(D) 1-Methyl-4-Chlorobenzene

Detailed Solution

Question 8:

What will be formed after oxidation reaction of secondary alcohol with chromic anhydride (CrO₃)?

(A) Aldehyde
(B) Ketone
(C) Carboxylic acid
(D) Ester

Detailed Solution

Question 9:

The conversion of phenol to salicylic acid can be accomplished by

(A) Reimer-Tiemann reaction
(B) Friedel-Crafts reaction
(C) Kolbe reaction
(D) Coupling reaction

Detailed Solution

Question 10:

Which of the following is/are examples of denaturation of protein?

(A) Coagulation of egg white
(B) Curdling of milk
(C) Clotting of blood
(D) Both (A) and (B)

Detailed Solution

Question 11:

Nucleotides are joined together by

(A) Glycosidic linkage
(B) Peptide linkage
(C) Hydrogen bonding
(D) Phosphodiester linkage

Detailed Solution

Question 12:

Scurvy is caused due to deficiency of

(A) Vitamin B1
(B) Vitamin B2
(C) Ascorbic acid
(D) Glutamic acid

Detailed Solution

Question 13:

Assertion (A): In a first order reaction, if the concentration of the reactant is doubled, its half-life is also doubled.

Reason (R): The half-life of a reaction does not depend upon the initial concentration of the reactant in a first order 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.

Detailed Solution

Question 14:

Assertion (A): Cu cannot liberate H₂ on reaction with dilute mineral acids.

Reason (R): Cu has positive electrode potential.

(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.

Detailed Solution

Question 15:

Assertion (A): Aromatic primary amines cannot be prepared by Gabriel Phthalimide synthesis.

Reason (R): Aryl halides do not undergo nucleophilic substitution reaction with the anion formed by phthalimide.

(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.

Detailed Solution

Question 16:

Assertion (A): Vitamin D cannot be stored in our body.

Reason (R): Vitamin D is fat soluble vitamin and is not excreted from the body in urine.

(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.

Detailed Solution

Question 17(A):

The rate constant for a zero order reaction A → P is 0.0030 mol L^-1s^-1. How long will it take for the initial concentration of A to fall from 0.10 M to 0.075 M?

Detailed Solution

Question 17(B) (OR):

The decomposition of NH₃ on platinum surface is zero order reaction. What are the rates of production of N₂ and H₂ if k = 2.5 × 10^-4 mol L^-1 s^-1?

Detailed Solution

Question 18:

Define the following terms:

(a) Pseudo first order reaction

(b) Half-life period of reaction (t_1/2)

Detailed Solution

Question 19:

Examine the following observations:

(a) Transition elements generally form coloured compounds.

(b) Zinc is not regarded as a transition element.

Detailed Solution

Question 20:

Name the following coordination compounds according to IUPAC norms:

(a) [Co(NH₃)₄(H₂O)Cl]Cl₂

(b) [CrCl₂(en)₂]Cl

Detailed Solution

Question 21(a):

In the following pair of halogen compounds, which compound undergoes S_N1 reaction faster and why?

Detailed Solution

Question 21(b):

Arrange the following compounds in increasing order of their reactivity towards S_N2 displacement:

2-Bromo-2-methylbutane, 1-Bromopentane, 2-Bromopentane.

Detailed Solution

Question 22:

At 25 °C the saturated vapour pressure of water is 24 mm Hg. Find the saturated vapour pressure of a 5% aqueous solution of urea at the same temperature. (Molar mass of urea = 60 g mol^-1)

Detailed Solution

Question 23:

The electrical resistance of a column of 0.05 M NaOH solution of area 0.8 cm² and length 40 cm is 5 × 10³ ohm. Calculate its resistivity, conductivity and molar conductivity.

Detailed Solution

Question 24:

Complete and balance the following chemical equations:
(a) \(\text{MnO}_4^- + \text{C}_2\text{O}_4^{2-} + \text{H}^+ \to \)
(b) \(\text{KMnO}_4 \xrightarrow[513\ \text{K}]{\text{Heat}} \)
(c) \(\text{Cr}_2\text{O}_7^{2-} + \text{H}_2\text{S} + \text{H}^+ \to \)

Detailed Solution

Question 25:

Using valence bond theory, explain the hybridization and magnetic character of the following:
(a) \([\mathrm{Co(NH_3)_6}]^{3+}\)
(b) \([\mathrm{Ni(CO)_4}]\)
[At. no. : Co = 27, Ni = 28]

Detailed Solution

Question 26(a):

Define the following:

(i) Enantiomers

(ii) Racemic mixture

Detailed Solution

Question 26(b):

Why is chlorobenzene resistant to nucleophilic substitution reaction?

Detailed Solution

Question 27(A)(a):

Explain the following reactions and write chemical equation involved:

Wolff-Kishner reduction

Detailed Solution

Question 27(A)(b):

Explain the following reactions and write chemical equation involved:

Etard reaction

Detailed Solution

Question 27(A)(c):

Explain the following reactions and write chemical equation involved:

Cannizzaro reaction

Detailed Solution

Question 27(B)(a) (OR):

Write the structures of A, B and C in the following sequence of reactions:

CH₃COOH ⟶{SOCl₂} A ⟶{H₂, Pd-BaSO₄} B ⟶{H₂N-NH₂} C

Detailed Solution

Question 27(B)(b) (OR):

Write the structures of A, B and C in the following sequence of reactions:

CH₃CN ⟶{1.(DIBAL-H); 2. H₂O} A ⟶{Dil. NaOH} B ⟶{Δ} C

Detailed Solution

Question 28:

Define the following terms:

(a) Glycosidic linkage

(b) Invert sugar

(c) Oligosaccharides

Detailed Solution

Question 29(a):

Read the passage and answer: The spontaneous flow of the solvent through a semipermeable membrane from a pure solvent to a solution or from a dilute solution to a concentrated solution is called osmosis. The phenomenon of osmosis can be demonstrated by taking two eggs of the same size. In an egg, the membrane below the shell and around the egg material is semipermeable. The outer hard shell can be removed by putting the egg in dilute hydrochloric acid. After removing the hard shell, one egg is placed in distilled water and the other in a saturated salt solution. After some time, the egg placed in distilled water swells-up while the egg placed in salt solution shrinks. The external pressure applied to stop the osmosis is termed as osmotic pressure (a colligative property). Reverse osmosis takes place when the applied external pressure becomes larger than the osmotic pressure.

(a) Define reverse osmosis. Name one SPM which can be used in the process of reverse osmosis.

Detailed Solution

Question 29(b):

What do you expect to happen when red blood corpuscles (RBC's) are placed in 0.5% NaCl solution?

Detailed Solution

Question 29(b) (OR):

Which one of the following will have higher osmotic pressure in 1M KCl or 1M urea solution. Justify your answer.

Detailed Solution

Question 29(c):

Why osmotic pressure is a colligative property?

Detailed Solution

Question 30(a):

Amines have a lone pair of electrons on nitrogen atom due to which they behave as Lewis base. Greater the value of \( K_b \) or smaller the value of \( pK_b \), stronger is the base. Amines are more basic than alcohols, ethers, esters, etc. The basic character of aliphatic amines should increase with the increase of alkyl substitution. But it does not occur in a regular manner as a secondary aliphatic amine is unexpectedly more basic than a tertiary amine in aqueous solutions. Aromatic amines are weaker bases than ammonia and aliphatic amines. Electron releasing groups such as \( -CH_3 \), \( -OCH_3 \), \( -NH_2 \), etc., increase the basicity while electron-withdrawing substituents such as \( -NO_2 \), \( -CN \), halogens etc., decrease the basicity of amines. The effect of these substitute is more at p\( ^- \) than at m\( ^- \) position.

(a) Arrange the following in the increasing order of their basic character. Give reason:

Detailed Solution

Question 30(b):

Why pK_b of aniline is more than that of methylamine?

Detailed Solution

Question 30(c):

Arrange the following in the increasing order of their basicity in an aqueous solution:
\(\text{(CH}_3\text{)}_3\text{N}, \ \text{(CH}_3\text{)}_2\text{NH}, \ \text{NH}_3, \ \text{CH}_3\text{NH}_2\)

Detailed Solution

Question 30(c) (OR):

Why ammonolysis of alkyl halides is not a good method to prepare pure amines?

Detailed Solution

Question 31(A)(a):

Give IUPAC name of CH₃-CH=CH-CHO.

Detailed Solution

Question 31(A)(b):

Give a simple chemical test to distinguish between propanal and propanone.

Detailed Solution

Question 31(A)(c):

How will you convert the following:

(i) Toluene to benzoic acid

(ii) Ethanol to propan-2-ol

(iii) Propanal to 2-hydroxy propanoic acid

Detailed Solution

Question 31(B) (OR):

Complete each synthesis by giving missing starting material, reagent or products:

Detailed Solution

Question 32(A)(a):

Calculate the standard Gibbs energy (\( \Delta G^\circ \)) of the following reaction at 25°C: \[ \text{Au}(s) + \text{Ca}^{2+}(1M) \to \text{Au}^{3+}(1M) + \text{Ca}(s) \] \[ E^\circ_{\text{Au}^{3+}/\text{Au}} = +1.5 \, \text{V}, \quad E^\circ_{\text{Ca}^{2+}/\text{Ca}} = -2.87 \, \text{V} \] Predict whether the reaction will be spontaneous or not at 25°C. [1 F = 96500 C mol\(^{-1}\)]

Detailed Solution

Question 32(A)(b):

Tarnished silver contains \( Ag_2S \). Can this tarnish be removed by placing tarnished silverware in an aluminium pan containing an inert electrolytic solution such as NaCl? The standard electrode potential for the half reaction: \[ \text{Ag}_2\text{S}(s) + 2e^- \to 2\text{Ag}(s) + S^{2-}(aq) \, (\text{E}^\circ = -0.71 \, \text{V}) \] \[ \text{Al}^{3+}(aq) + 3e^- \to \text{Al}(s) \, (\text{E}^\circ = -1.66 \, \text{V}) \]

Detailed Solution

Question 32(B)(a) (OR):

Define the following:

(i) Cell potential

(ii) Fuel cell

Detailed Solution

Question 32(B)(b) (OR):

Calculate the emf of the following cell at 25°C:
\[ \text{Zn(s)} | \text{Zn}^{2+}(0.1M) || \text{Cd}^{2+}(0.01M) | \text{Cd(s)} \] Given: \[ E^\circ_{\text{Cd}^{2+}/\text{Cd}} = -0.40 \, V, \, E^\circ_{\text{Zn}^{2+}/\text{Zn}} = -0.76 \, V \] \[ [\log 10 = 1] \]

Detailed Solution

Question 33(A):

An organic compound 'A', molecular formula C₂H₆O oxidises with CrO₃ to form a compound 'B'. Compound 'B' on warming with iodine and aqueous solution of NaOH gives a yellow precipitate of compound 'C'. When compound 'A' is heated with conc. H₂SO₄ at 413 K gives a compound 'D', which on reaction with excess HI gives compound 'E'. Identify compounds 'A', 'B', 'C', 'D' and 'E' and write chemical equations involved.

Detailed Solution

Question 33(B) (OR):

(B) (a) Write chemical equations of the following reactions:

(i) Phenol is treated with conc. HNO₃

(ii) Propene is treated with B₂H₆ followed by oxidation by H₂O₂/OH^-.

(iii) Sodium t-butoxide is treated with CH₃Cl.

(b) Give a simple chemical test to distinguish between butan-1-ol and butan-2-ol.

(c) Arrange the following in increasing order of acid strength:

phenol, ethanol, water

Detailed Solution - Part 1 | Detailed Solution - Part 2 | Detailed Solution - Part 3

CBSE Class 12 Chemistry 2025 Set 1 (56/2/1) Exam Pattern and Marking Scheme

Section	Questions	Question Type	Marks Each	Total Marks
A	Q1 - Q16	Multiple Choice Questions	1	16
B	Q17 - Q21	Very Short Answer	2	10
C	Q22 - Q28	Short Answer	3	21
D	Q29 - Q30	Case-Study based	4	8
E	Q31 - Q33	Long Answer	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

CBSE Class 12 Chemistry 2025 | Paper Analysis

Source: Chemistry Concept

CBSE Class 12 Chemistry 2025 Set 1 (56/2/1) Question Paper FAQs

Ques. How many questions are there in the CBSE Class 12 Chemistry 2025 Set 1 (56/2/1) question paper?

Ans. The paper has 33 questions in five sections (A to E) for 70 marks: 16 MCQs of 1 mark, 5 very short answer questions of 2 marks, 7 short answer questions of 3 marks, 2 case-study questions of 4 marks and 3 long answer questions of 5 marks.

Ques. Is a calculator allowed in the CBSE Class 12 Chemistry 2025 exam?

Ans. No. The general instructions printed on the Set 1 (56/2/1) paper state that the use of a calculator is not allowed. The paper lists the physical constants you may need, so you do not have to memorise them.

Ques. How much time do you get for the CBSE Class 12 Chemistry 2025 paper?

Ans. The paper is of 3 hours (10:30 AM to 1:30 PM). The question paper is handed out at 10:15 AM, and you get 15 minutes to read it before writing starts at 10:30 AM.

Ques. What does the Q.P. code 56/2/1 mean?

Ans. 56/2/1 is the Q.P. code printed on the cover of this question paper: 56 is the number CBSE uses for the Chemistry paper and the last number is the set (Set 1). CBSE issued several such codes for the same exam, all with the same 70-mark pattern.

Ques. Where can I get the official CBSE Class 12 Chemistry 2025 question paper?

Ans. The official question papers are published on the CBSE website, cbse.gov.in, under the previous year question papers section.

CBSE Class 12 Chemistry Question Paper 2025 (Set 1 - 56/2/1)

CBSE Class 12 Chemistry Question Paper 2025 (Set 1 - 56/2/1) with Solution PDF

CBSE Class 12 Chemistry 2025 Set 1 (56/2/1) Questions with Solutions

CBSE Class 12 Chemistry 2025 Set 1 (56/2/1) Exam Pattern and Marking Scheme

CBSE Class 12 Chemistry Unit-Wise Weightage

CBSE Class 12 Chemistry 2025 | Paper Analysis

CBSE Class 12 Chemistry 2025 Set 1 (56/2/1) Question Paper FAQs

CBSE CLASS XII Questions

1.
A reaction \( \mathrm{A \rightarrow B} \) follows second order kinetics. How will the rate of reaction be affected if the concentration of (i) A is increased by three times, and (ii) A is reduced to half ?

2.
Draw the structure of 'X' in the following reaction:

4.
From the given data of \(E^{\circ}\) values, answer the following questions :
(I) Why \(E^{\circ}_{M^{2+}/M}\) show irregular trend in the above values ?
(II) Why is \(E^{\circ}_{Cu^{2+}/Cu}\) value exceptionally positive ?
(III) Why \(E^{\circ}_{Mn^{2+}/Mn}\) value is highly negative ?

5.
Which of the following curve represents the first order reaction?

6.
An organic compound (X) has the molecular formula \(C_5H_{10}O\). Draw structures for (X) if it:
(I) does not give Tollen's test but gives a positive iodoform test.
(II) does not give Tollen's test and iodoform test but undergoes Aldol condensation.
(III) undergoes Cannizzaro's reaction.

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CBSE Class 12 Chemistry Question Paper 2025 (Set 1 - 56/2/1) with Solution PDF

CBSE Class 12 Chemistry 2025 Set 1 (56/2/1) Questions with Solutions

CBSE Class 12 Chemistry 2025 Set 1 (56/2/1) Exam Pattern and Marking Scheme

CBSE Class 12 Chemistry Unit-Wise Weightage

CBSE Class 12 Chemistry 2025 | Paper Analysis

CBSE Class 12 Chemistry 2025 Set 1 (56/2/1) Question Paper FAQs

CBSE CLASS XII Questions

1.A reaction \( \mathrm{A \rightarrow B} \) follows second order kinetics. How will the rate of reaction be affected if the concentration of (i) A is increased by three times, and (ii) A is reduced to half ?

2.Draw the structure of 'X' in the following reaction:

4.From the given data of \(E^{\circ}\) values, answer the following questions : (I) Why \(E^{\circ}_{M^{2+}/M}\) show irregular trend in the above values ? (II) Why is \(E^{\circ}_{Cu^{2+}/Cu}\) value exceptionally positive ? (III) Why \(E^{\circ}_{Mn^{2+}/Mn}\) value is highly negative ?

5.Which of the following curve represents the first order reaction?

6.An organic compound (X) has the molecular formula \(C_5H_{10}O\). Draw structures for (X) if it: (I) does not give Tollen's test but gives a positive iodoform test. (II) does not give Tollen's test and iodoform test but undergoes Aldol condensation. (III) undergoes Cannizzaro's reaction.

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1.
A reaction \( \mathrm{A \rightarrow B} \) follows second order kinetics. How will the rate of reaction be affected if the concentration of (i) A is increased by three times, and (ii) A is reduced to half ?

2.
Draw the structure of 'X' in the following reaction:

4.
From the given data of \(E^{\circ}\) values, answer the following questions :
(I) Why \(E^{\circ}_{M^{2+}/M}\) show irregular trend in the above values ?
(II) Why is \(E^{\circ}_{Cu^{2+}/Cu}\) value exceptionally positive ?
(III) Why \(E^{\circ}_{Mn^{2+}/Mn}\) value is highly negative ?

5.
Which of the following curve represents the first order reaction?

6.
An organic compound (X) has the molecular formula \(C_5H_{10}O\). Draw structures for (X) if it:
(I) does not give Tollen's test but gives a positive iodoform test.
(II) does not give Tollen's test and iodoform test but undergoes Aldol condensation.
(III) undergoes Cannizzaro's reaction.