JKBOSE Class 12 Chemistry Guess paper 2025

JKBOSE Class 12 Chemistry Guess paper 2025 syllabus and the unit-wise weightage, here’s a guess paper for the upcoming exam. This guess paper is designed to cover high-weightage topics and frequently asked questions.

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JKBOSE Class 12 Chemistry Guess paper 2025

Unit-I: SOLUTIONS (7 Marks)

1. Very Short Answer (1 mark)
   • Define colligative properties.
   • What is Van’t Hoff factor?
2. Short Answer I (2 marks)
   • Derive the expression for relative lowering of vapor pressure.
   • Calculate the molecular mass of a solute if the osmotic pressure of its solution is given.
3. Long Answer (4 marks)
   • Explain Raoult’s law and its limitations. Derive the expression for elevation in boiling point.

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Unit-II: ELECTROCHEMISTRY (9 Marks)

1. Very Short Answer (1 mark)
   • What is the standard hydrogen electrode (SHE)?
   • Define molar conductivity.
2. Short Answer I (2 marks)
   • State Kohlrausch’s law of independent migration of ions.
   • Write the Nernst equation and explain its terms.
3. Short Answer II (3 marks)
   • Explain the working of a lead-acid battery with a diagram.
   • Calculate the emf of a cell using the Nernst equation.
4. Long Answer (5 marks)
   • Derive the relationship between Gibbs energy change and emf of a cell. Discuss the applications of fuel cells.

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Unit-III: CHEMICAL KINETICS (7 Marks)

1. Very Short Answer (1 mark)
   • Define the rate of reaction.
   • What is the half-life period of a reaction?
2. Short Answer I (2 marks)
   • Derive the integrated rate equation for a first-order reaction.
   • Explain the effect of temperature on the rate of reaction using the Arrhenius equation.
3. Long Answer (4 marks)
   • Discuss the collision theory of chemical reactions. Derive the expression for the rate constant of a zero-order reaction.

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Unit-IV: d and f-BLOCK ELEMENTS (7 Marks)

1. Very Short Answer (1 mark)
   • What is lanthanide contraction?
   • Why are transition metals good catalysts?
2. Short Answer I (2 marks)
   • Explain the preparation of K₂Cr₂O₇ from chromite ore.
   • Discuss the magnetic properties of transition metals.
3. Long Answer (4 marks)
   • Compare the properties of lanthanides and actinides. Explain the catalytic properties of transition metals.

Unit-V: CO-ORDINATION COMPOUNDS (7 Marks)

1. Very Short Answer (1 mark)
   • What is a ligand? Give an example.
   • Define coordination number.
2. Short Answer I (2 marks)
   • Explain Werner’s theory of coordination compounds.
   • Write the IUPAC name of [Co(NH₃)₆]Cl₃.
3. Long Answer (4 marks)
   • Discuss the bonding in coordination compounds using Valence Bond Theory (VBT). Explain the importance of coordination compounds in biological systems.

Unit-VI: HALOALKANES AND HALOARENES (6 Marks)

1. Very Short Answer (1 mark)
   • What is the nature of the C-X bond in haloalkanes?
   • Give the structure of iodoform.
2. Short Answer I (2 marks)
   • Explain the mechanism of SN2 reaction in haloalkanes.
   • Discuss the environmental effects of DDT.
3. Long Answer (3 marks)
   • Compare the reactivity of haloalkanes and haloarenes towards nucleophilic substitution reactions.

Unit-VII: ALCOHOLS, PHENOLS AND ETHERS (6 Marks)

1. Very Short Answer (1 mark)
   • What is the acidic nature of phenol?
   • Give the structure of methanol.
2. Short Answer I (2 marks)
   • Explain the mechanism of dehydration of alcohols.
   • Discuss the electrophilic substitution reactions of phenol.
3. Long Answer (3 marks)
   • Compare the physical and chemical properties of alcohols and phenols.

Unit-VIII: ALDEHYDES, KETONES AND CARBOXYLIC ACIDS (8 Marks)

1. Very Short Answer (1 mark)
   • What is the reactivity of alpha hydrogen in aldehydes?
   • Give the structure of acetic acid.
2. Short Answer I (2 marks)
   • Explain the nucleophilic addition reaction in carbonyl compounds.
   • Discuss the Hell-Volhard-Zelinskii reaction.
3. Long Answer (5 marks)
   • Compare the physical and chemical properties of aldehydes and ketones. Explain the mechanism of aldol condensation.

Unit-IX: ORGANIC COMPOUNDS CONTAINING NITROGEN (6 Marks)

1. Very Short Answer (1 mark)
   • What is diazotization?
   • Give the structure of aniline.
2. Short Answer I (2 marks)
   • Explain the Hoffmann bromamide reaction.
   • Discuss the basicity of amines.
3. Long Answer (3 marks)
   • Compare the physical and chemical properties of primary, secondary, and tertiary amines.

Unit-X: BIOMOLECULES (7 Marks)

1. Very Short Answer (1 mark)
   • What are reducing sugars?
   • Define denaturation of proteins.
2. Short Answer I (2 marks)
   • Explain the structure of glucose.
   • Discuss the functions of nucleic acids.
3. Long Answer (4 marks)
   • Compare the structures of DNA and RNA. Explain the importance of vitamins in the human body.

Tips for Preparation

1. Focus on NCERT: All questions are based on NCERT concepts.
2. Practice Numericals: Especially from Solutions, Electrochemistry, and Chemical Kinetics.
3. Revise Named Reactions: Mechanisms and distinguishing tests.
4. Memorize Structures: Biomolecules (glucose, DNA), coordination geometries.

Important Naming Reactions – Class 12 (JKBOSE)

Additional Naming Reactions – Class 12 (JKBOSE)