CBSE Class 12 Chemistry Half Yearly Sample Paper 2025 with Solution, Download PDF

CBSE Class 12 Chemistry Half Yearly Sample Paper 2025: The CBSE Class 12 Chemistry Half Yearly Sample Paper for the academic year 2025-26 is a crucial tool for students getting ready for their mid-term tests. These sample papers help students check how well they understand the topics and get used to the exam format and the kinds of questions they might see in their final exams. By practicing with these papers, students can find out what they are good at and what they need to work on. This helps them prepare better for the end term exam.

These question papers help students understand the exam pattern, identify key topics, and become familiar with the types of questions that might appear in the exams. Students can easily find and download these papers from the below mentioned link, making them a useful way to test themselves and review what they've learned. These sample papers by experts are designed to help the students for their Half Yearly exam. In this article we have covered all the topics and important questions so that students can check and practice to score well. After viewing all the questions students can download the PDF for sample paper and solutions. 

CBSE Class 12 Chemistry Half Yearly Sample Paper 2025

Read the following instructions carefully.
(a) There are 33 questions in this question paper with internal choice.
(b) SECTION A consists of 16 multiple-choice questions carrying 1 mark each.
(c) SECTION B consists of 5 short answer questions carrying 2 marks each.
(d) SECTION C consists of 7 short answer questions carrying 3 marks each.
(e) SECTION D consists of 2 case-based questions carrying 4 marks each.
(f) SECTION E consists of 3 long answer questions carrying 5 marks each.
g) All questions are compulsory.
(h) Use of log tables and calculators is not allowed.

Section A 

1. Ammonolysis of ethyl chloride followed by reaction of the amine so formed with mole of methyl chloride gives an amine that
a. reacts with Hinsberg reagent to form a product soluble in an alkali.
b. on reaction with Nitrous acid, produced nitrogen gas.
c. reacts with Benzenesulphonyl chloride to form a product that is insoluble in alkali.
d. does not react with Hinsberg reagent.

2. Which one of the following has the highest dipole moment?

3. On increasing temperature,

(a) ionic conductance increases and electronic conductance decreases.
(b) ionic conductance decreases and electronic conductance increases.
(c) both ionic and electronic conductance increase.
(d) both ionic and electronic conductance decrease.

4. 

5. 

a. (i)-(C), (ii)-(B), (iii)-(A)
b. (i)-(C), (ii)-(A), (iii)-(B)
c. (i)-(A), (ii)-(B), (iii)-(C)
d. (i)-(B), (ii)-(A), (iii)-(C)

6. 

7. The unit of rate and rate constant are same for a reaction of –

(a) zero order (b) first order
(c) Second order (d) third order

8. Formic acid and ethanoic acid can be distinguished by:

(a) Sod. Bicarbonate test (b) Tollen’s test
(c) Iodoform test (d) Lucas test

9. Which of the following statements is not true about glucose?

(a) It is an aldohexose. (b) On heating with HI it forms n-hexane.
(c) It is present in furanose form. (d) It does not give 2,4-DNP test

11. 

12. 

For questions number 13 to 16, two statements are given one labelled as Assertion (A) and the other labelled as Reason (R). Select the correct answer to these questions from the codes (A), (B), (C) and (D) as given below:

(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.

13. Assertion (A): The half- life for a zero order reaction is independent of the initial concentration of the reactant.

Reason (R): For a zero order reaction, Rate = k  

14. Assertion (A) : Transition metals have high melting point.

Reason (R) : Transition metals have completely filled d-orbitals.

15. 

16. 

Section-B

17. (i) Why is an increase in temperature observed on mixing chloroform and acetone?

(ii) Why does sodium chloride solution freeze at a lower temperature than water?

18. 

19. 

20. 

21. The presence of Carbonyl group in glucose is confirmed by its reaction with hydroxylamine. Identify the type of carbonyl group present and its position. Give a chemical reaction in support of your answer.

Section-C

22. Define the following terms:

(i) Pseudo first order reaction

(ii) Half-life period of a reaction

(iii) Molecularity of a reaction.

23. Account for the following:

a. The lowest oxide of transition metal is basic, and the highest is acidic.

b. Chromium is a hard metal while mercury is a liquid metal

c. The ionisation energy of elements of the 3d series does not vary much with increasing atomic number.

24. 

25. 

26. Neeta was experimenting in the lab to study the chemical reactivity of alcohols. She carried out a dehydration reaction of propanol at 140oC to 180oC. Different products were obtained at these two temperatures.

a. Identify the major product formed at 140oC and the substitution mechanism followed in this case.

b. Identify the major product formed at 180oC

27. a. Give the chemical reaction involved when p-nitrotoluene undergoes Etard reaction.

b. Why does Benzoic acid exist as a dimer in an aprotic solvent?

c. Benzene on reaction with methylchloride in the presence of anhydrous AlCl3 forms toluene. What is the expected outcome if benzene is replaced by benzoic acid? Give a reason for your answer.

OR

An organic compound ‘X’, does not undergo aldol condensation. However ‘X’ with compound ‘Y’ in the presence of a strong base react to give the compound 1,3-diphenylprop-2-en-1-one.

a. Identify ‘X’ and ‘Y’

b. Write the chemical reaction involved.

c.Give one chemical test to distinguish between X and Y.

SECTION - D

29. Coordination compounds contain a metallic element as the central atom and are therefore referred to as metal complexes. These types of coordination complexes generally consist of a transition element as the central atom. It can be noted that the central atom in these complexes is called the coordination centre. A chemical compound in which the central ion or atom (or the coordination centre) is bound to a set number of atoms, molecules, or ions is called a coordination entity. Some examples of such coordination entities include [CoCl3(NH3)3] and [Fe(CN)6]4-. In coordination compounds, the central atoms or ions are typically Lewis Acids and can, therefore, act as electron-pair acceptors. The atoms, molecules, or ions that are bound to the coordination centre or the central atom/ion are referred to as ligands. These ligands can either be a simple ion or molecule, such as Cl– or NH3 or in the form of relatively large molecules, such as ethane-1,2-diamine (NH2-CH2-CH2-NH2). The coordination sphere is the non-ionizable part of a complex compound, which consists of a central transition metal ion surrounded by neighbouring atoms or groups enclosed in a square bracket.

30. 

The experimental data is tabulated below:

(source: Hall Jr, H. K. (1956). Field and inductive effects on the base strengths of amines. Journal of the American Chemical Society, 78(11), 2570-2572.)

Study the above data and answer the following questions: 

a. Plot a graph between the electronegativity of the substituent vs pKb value of the corresponding substituted propyl amine (given that pKa + pKb =14). Is there any relation between the electronegativity of the substituent and its basic strength?

(i) 9.9 (ii) 9.5 (iii) 9.3 (iv) 9.1

c. The pKa value of the substituted piperidine formed with substituent “X” is found to be 8.28. What is the expected electronegativity of “X”

(i)3.5 (ii)3.4 (iii)3.8 (iv) 3.1  

OR

What is the most suitable pKa value of the substituted propylamine formed with substituent “X” with electronegativity 3.0 (i)10.67 (ii)10.08 (iii)10.15 (iv)11.10 

SECTION - E

31. 

32. a. Give reasons for the following: (i)The reaction of ethanol with acetyl chloride is carried out in the presence of pyridine.

(ii) Cresols are less acidic than phenol.

b. Williamson’s process is used for the preparation of ethers from alkyl halide. Identify the alkyl bromide and sodium alkoxide used for the preparation of 2- Ethoxy-3-methylpentane

c. Convert: (i) Toluene to 3-nitrobenzoic acid. (ii) Benzene to m-nitroacetophenone

OR

a. Out of formic acid and acetic acid, which one will give the HVZ reaction? Give a suitable reason in support of your answer and write the chemical reaction involved.

b. Alcohols are acidic but they are weaker acids than water. Arrange various isomers of butanol in the increasing order of their acidic nature. Give a reason for the same.

c. An organic compound A which is a Grignard reagent is used to obtain 2-methylbutan-2-ol on reaction with a carbonyl compound ‘B’ . Identify A’ and ‘B’. Write the equation for the reaction between A and B.

33. 

CBSE Class 12 Chemistry Half Yearly Sample Paper 2025: Answer Key

Section-A
1.	(c) reacts with Benzenesulphonyl chloride to form a product that is insoluble in alkali
2	(b)CH3Cl The order followed is this CH3I<CH3Br<CH3F< CH3Cl , though F is most electronegative, the bond length is small as compared to C-Cl. Dipole moment is the product of the charge and the bond length.
3.	(a) ionic conductance increases and electronic conductance decreases.
4.
5.	(a) (i)-(C), (ii)-(B), (iii)-(A)
6.
7.	(a) zero order
8.	(b) Tollen’s test
9.	(c) It is present in furanose form.
10.	(a) (a) < (b) < (c) < (d)
11.
12.
13.
14.	(C)Assertion (A) is true, but Reason (R) is false.
15.	(A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
16.	(D)Assertion (A) is false, but Reason (R) is true.
Section-B
17.	(i) The bonds between chloroform molecules and molecules of acetoneare dipole-dipole interactions but on mixing, the chloroform and acetone molecules, they start forming hydrogen bonds which are stronger bonds resulting in the release of energy. This gives rise to an increase in temperature. (ii) When a non-volatile solute is dissolved in a solvent, the vapour pressure decreases. As a result, the solvent freezes at a lower temperature.
18.	(a) Potassium diaquadioxalatochromate(III) hydrate (b) (i) Haemoglobin: Iron (ii) Vitamin B-12: Cobalt
19.
20.
21.	The carbonyl group present in glucose is aldehyde and the C1 atom . Glucose gets oxidised to six-carbon carboxylic acid (gluconic acid) with COOH group at the C1 atom on reaction with a mild oxidising agent like bromine water. This indicates that the carbonyl group is present as an aldehydic group
Section-C
22.	Pseudo-First-Order Reaction: A reaction that appears to be a first-order reaction but is, in fact, a second-order reaction. This happens when one of the reactants is present in a very large excess, so its concentration remains essentially constant during the reaction. The rate of the reaction then depends only on the concentration of the other reactant, making it look like a first-order reaction. A common example is the hydrolysis of an ester in the presence of a large amount of water. Half-Life Period (t1/2): The time required for the concentration of a reactant to decrease to one-half of its initial value. It is a key parameter used to describe the rate of a chemical reaction. For a first-order reaction, the half-life is independent of the initial concentration, while for a zero-order reaction, it is directly proportional to the initial concentration. Molecularity of a Reaction: The number of reacting species (atoms, ions, or molecules) that must collide simultaneously to bring about an elementary chemical reaction. It is a theoretical concept determined by the mechanism of a reaction, and it can only be a whole number (1, 2, or 3). Unlike the order of a reaction, which can be zero, fractional, or negative, molecularity is always a positive integer.
23.	(a) In the case of a lower oxide of a transition metal, the metal atom has some electrons present in the valence shell of the metal atom that are not involved in bonding. As a result, it can donate electrons and behave as a base whereas in higher oxide of a transition metal, 1 3 the metal atom does not have an electron in the valence shell for donation. As a result, it can accept electrons and behave as an acid. (b) Chromium has unpaired electrons which result in strong metallic bonding which results in it being a hard solid and the absence of unpaired electrons in Hg results in it being a liquid. (c) The increase in effective nuclear charge responsible for steady increase in ionisation energy is counterbalanced by shielding effect of (n-1)d electrons
24.
25.
26.
27.
28.
SECTION - D
29.
30.
SECTION - E
31.
32.	a. (i) The reaction of ethanol with acetyl chloride is carried out in the presence of pyridine . Pyridine is a strong organic base .The function of pyridine is to remove HCl formed in the reaction. (ii) The electron releasing groups, such as alkyl groups, in general, do not favour the formation of phenoxide ion resulting in decrease in acid strength. Cresols, for example, are less acidic than phenol. a. Acetic acid will give HVZ reaction. Carboxylic acids having an α-hydrogen are halogenated at the α-position on treatment with chlorine or bromine in the presence of a small amount of red phosphorus to give α-halo carboxylic acids. b. Isomers of butanol are: Butan-1-ol , butan-2-ol , 2-methylpropanol , 2-methylpropan-2-ol . Acidic strength in isomeric alcohols varies as follows
33.

To download the full PDF of the sample paper and its solutions, please click on the link provided below. Practicing these papers will significantly enhance your understanding and boost your scores