CHE-005 IGNOU Guess Paper 2026-27

CHE-005 Guess Paper 2026–27: Term-End Exam (TEE) Focus & Previous Year Patterns

This structured guess paper aligns with the IGNOU Chemistry (CHE-005) curriculum, emphasizing high-yield topics from past June/December sessions (2017–2026). It includes chapter-wise question distribution, time management strategies, and solved-style questions for optimal preparation.

Key Syllabus Blocks & Question Weightage

Based on official IGNOU CHE-005 units, the following blocks are prioritized for scoring:

• Unit 1: Chemical Bonding & Molecular Geometry
  • Valence Bond Theory (VBT) and Hybridization (25–30% weightage). Focus on sp³, sp², dsp², and d²sp³ hybridization problems.
  • Molecular Orbital Theory (MOT) for homonuclear diatomic molecules (e.g., O₂, N₂). Expect 2–3 numericals on bond order and magnetic properties.
• Unit 3: Reaction Kinetics & Catalysis
  • Rate laws, order of reactions, and integrated rate equations (15–20%). Practice problems on first-order/second-order kinetics (e.g., decomposition of H₂O₂).
  • Catalysis mechanisms (homogeneous/heterogeneous). Prioritize enzyme-like catalysis (e.g., acid-base catalysis) and transition-state theory.
• Unit 5: Organic Reaction Mechanisms
  • SN1/SN2/E1/E2 mechanisms with stereochemical outcomes (30–35%). Solve problems involving inversion of configuration (Walden inversion) and carbocation stability.
  • Electrophilic Aromatic Substitution (EAS) and nucleophilic aromatic substitution. Focus on directing effects (–I, +M, –M) and mechanism steps.
• Unit 7: Coordination Chemistry & Spectroscopy
  • Crystal Field Theory (CFT) and Ligand Field Theory (LFT). Expect questions on color, magnetic moment, and CFSE (Crystal Field Stabilization Energy) calculations.
  • IR and UV-Vis spectroscopy (20%). Practice interpreting spectra for coordination compounds (e.g., [Co(NH₃)₆]³⁺ vs. [Co(CN)₆]³⁻).
• Unit 9: Laboratory Techniques & Qualitative Analysis
• Practical-based questions on precipitation titrations, gravimetric analysis, and spot tests (e.g., identification of anions/cations like SO₄²⁻, Fe³⁺).

Exam Time Management (3 Hours)

Allocate time as follows for 100 marks:

• Section A (20 marks): 30 minutes. Answer all short-answer questions (e.g., definitions, mechanisms, or single-step calculations).
• Section B (40 marks): 70 minutes. Prioritize numerical problems from Units 1, 3, and 5 (high weightage). Leave 10 minutes for review.
• Section C (40 marks): 60 minutes. Focus on Units 5 and 7 (organic mechanisms and spectroscopy). Sketch reaction pathways or spectra if required.

Frequently Asked Questions (FAQs)

Q: Are numerical problems from thermodynamics (Unit 4) included in the guess paper? Yes, but with lower weightage (~10%). Focus on Gibbs free energy (ΔG°), entropy (ΔS°), and Le Chatelier’s principle applications.

Q: How should I approach stereochemistry questions in Unit 5? Practice drawing Fischer projections, R/S configurations, and predicting products of reactions involving chiral centers (e.g., bromination of alkenes with chiral starting materials).

Sample Question Patterns (Based on Past Papers)

• Unit 1: Calculate hybridization and bond angles for PF₅ or XeF₄ using VBT/MOT.
• Unit 3: Derive the rate law for the reaction 2NO(g) + O₂(g) 2NO₂(g) given experimental data.
• Unit 5: Predict the major product of the reaction between 2-bromobutane and hydroxide ion (SN1 vs. SN2).
• Unit 7: Explain the color of [Ti(H₂O)₆]³⁺ using CFT and calculate its CFSE.
• Unit 9: Describe the procedure for identifying Cl⁻ ions using AgNO₃ solution.

Note: Emphasize mechanistic reasoning and mathematical accuracy for full marks. Avoid memorization-heavy topics like nomenclature unless explicitly asked.