HBSE 12th Chemistry Solved Paper 2025

Haryana Board of School Education (HBSE) Class 12 Chemistry Question Paper and Answer Key Exam 2025

In this article, we provide comprehensive solutions and detailed explanations for chemistry questions asked in Haryana Board Class 12th exam 2025. Students can check their answer and it is also useful for students who will appear in next year exam. Our aim is to provide a valuable resource that not only helps in understanding the correct answers but also clarifies the underlying concepts.

SECTION – A
[ Objective Type Questions ]

Select the correct option of the following multiple choice questions (1-9)

Which of the following is not a colligative property ?

(A) Relative lowering of vapour pressure
(B) Elevation in boiling point
(C) Depression in freezing point
(D) Depression in boiling point

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Option (D) depression in boiling point is correct answer.

Explanation: There are four colligative properties, they are-

1. Relative lowering of vapor pressure
2. Elevation in boiling point
3. Depression in freezing point
4. Osmotic Pressure

During electrolysis of aqueous solution of NaCl, the products formed are :

(A) Na, Cl₂
(B) NaOH, Cl₂, H₂
(C) Na, Cl₂, NaOH
(D) H₂, Cl₂

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Option (B) NaOH, Cl₂, H₂ is correct answer.

Explanation: Electrolysis of an aqueous solution of sodium chloride (brine) produces sodium hydroxide (NaOH), chlorine gas (Cl₂), and hydrogen gas (H₂).
At the cathode: 2H⁺ + 2e⁻ → H₂
At the anode: 2Cl⁻ → Cl₂ + 2e⁻ Overall reaction: Na⁺ + OH⁻ → NaOH

Which of the following compounds has highest melting point ?

(A) 1,2 dichlorobenzene
(B) 1,3 dichlorobenzene
(A) 1,4 dichlorobenzene
(A) All have same melting point

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Option (A) 1,4 dichlorobenzene is correct answer.

Explanation: 1,4-Dichlorobenzene (para-dichlorobenzene) is the most symmetrical among the dichlorobenzene isomers. Its symmetrical structure allows for more efficient packing in the crystal lattice, leading to stronger intermolecular forces and thus a higher melting point.

The major use of chloroform today is :

(A) In the production of Freon refrigerant R-22
(B) As an anaesthetic in surgery
(C) In the production of medicines
(D) All of the above

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Option (A) In the production of Freon refrigerant R-22 is correct answer.

Explanation: The primary industrial use of chloroform is in the production of chlorodifluoromethane (Freon R-22), a refrigerant. It is also used as an anesthetic.

Which of the following compounds gives Cannizaro reaction ?

(A) Cyclohexanecarboxaldehyde
(B) Acetaldehyde
(C) Isobutyraldehyde
(D) Benzaldehyde

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Option (D) Benzaldehyde is correct answer.

Explanation: The Cannizzaro reaction is given by aldehydes that do not have an alpha-hydrogen atom. It is a disproportionation reaction in which one molecule of the aldehyde is oxidized to a carboxylic acid, and another molecule is reduced to an alcohol. The reaction carried out in the presence of a strong base.

Reaction of bromine water with phenol gives :

(A) 2, 4, 6-Tribromophenol
(B) o-Bromophenol and p-Bromophenol
(C) o-Bromophenol
(D) p-Bromophenol

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Option (A) 2, 4, 6-Tribromophenol is correct answer.

Explanation: When phenol reacts with bromine water, the −OH group is a strongly activating group and directs bromine to all available ortho and para positions, resulting in the formation of 2, 4, 6-Tribromophenol. However, phenol with bromine in nonpolar solvent like CS₂, o-Bromophenol and p-Bromophenol are formed.

Which of the following is most basic ?

(A) C₆H₅NH₂
(B) NH₃
(C) C₂H₅NH₂
(D) (C₂H₅)₂NH

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Option (D) (C₂H₅)₂NH is correct answer.

Explanation: The basicity of amines in aqueous solution is generally explained by a combination of inductive effect, steric hindrance, and solvation effects.

Order of basic strength:
When R is Ethyl group: R₂NH > R₃N > RNH₂
When R is Methyl group: R₂NH > R₁N > RNH₃

Hofmann bromamide degradation reaction is shown by :

(A) CH₃CH₂NH₂
(B) CH₃CH₂NO₂
(C) CH₃CONH₂
(D) CH₃CH₂CN

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Option (C) CH₃CONH₂ is correct answer.

Explanation: Hofmann bromamide degradation reaction is a reaction that converts a primary amide into a primary amine with one carbon atom less than the original amide.

What type of isomers [Co(NH₂)₅Cl]SO₄ and [Co(NH₃)₅(SO₄)]Cl are ?

(A) Linkage
(B) Coordination
(C) Ionisation
(D) Solvate

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Option (C) Ionisation is correct answer.

Explanation: Ionisation isomers are compounds that have the same molecular formula but give different ions in solution.
[Co(NH₂)₅Cl]SO₄ will produce [Co(NH₂)₅Cl]²⁺ and SO₄²⁻ ions in solution.
[Co(NH₃)₅(SO₄)]Cl will produce [Co(NH₃)₅(SO₄)]⁺ and Cl⁻ ions in solution.