Chemistry

---
name: chemistry
description: >-
  CBSE Grade 12 Chemistry — Full Syllabus Mastery (2026-27). 
  Covers Physical, Inorganic, and the 33-mark Organic giant. 
  Target: 70/70 Theory + 30/30 Practical.
---

# Chemistry — CBSE Grade 12 (PCMB/PCMC)

## Syllabus Blueprint (2026–27)

| Unit | Chapters | Marks |
|------|----------|-------|
| Physical | Solutions, Electrochemistry, Chemical Kinetics | 23 |
| Inorganic | d- and f- Block Elements, Coordination Compounds | 14 |
| Organic | Haloalkanes, Alcohols, Aldehydes, Amines, Biomolecules | 33 |
| **Total** | **10 Chapters** | **70** |

---

## Unit I: Physical Chemistry (23 Marks)

### Key Concepts
- **Solutions:** Raoult's Law, Ideal/Non-ideal solutions, Colligative properties (Elevation in BP, Depression in FP, Osmotic Pressure), van't Hoff factor.
- **Electrochemistry:** Nernst Equation, Conductivity, Molar Conductivity, Kohlrausch's Law, Faraday's Laws, Fuel cells, Corrosion.
- **Kinetics:** Rate of reaction, Order/Molecularity, Integrated rate equations (Zero and First order), Half-life, Arrhenius Equation.

### Key Formulas
```latex
Raoult's Law: P = P^o \chi
Elevation in BP: \Delta T_b = i K_b m
Depression in FP: \Delta T_f = i K_f m
Osmotic Pressure: \pi = i CRT
Nernst Eq: E_{cell} = E^o_{cell} - \frac{0.0591}{n} \log Q
Molar Conductivity: \Lambda_m = \frac{\kappa \times 1000}{M}
First Order Rate: k = \frac{2.303}{t} \log \frac{[R]_0}{[R]}
Half-life (1st order): t_{1/2} = \frac{0.693}{k}
Arrhenius: \log \frac{k_2}{k_1} = \frac{E_a}{2.303R} \left( \frac{1}{T_1} - \frac{1}{T_2} \right)
```

---

## Unit II: Inorganic Chemistry (14 Marks)

### Key Concepts
- **d- and f- Block:** Electronic configuration, Transition metal properties (Colored ions, Catalytic property, Alloy formation), Lanthanoid contraction.
- **Coordination Compounds:** Werner’s theory, IUPAC nomenclature, VBT (Hybridization/Magnetic moment), CFT (Crystal field splitting), Isomerism.

### High-Yield Facts
- **KMnO4 / K2Cr2O7:** Preparation and oxidizing properties (Structure is high-yield).
- **VBT:** Identifying Inner/Outer orbital complexes (e.g., $[Co(NH_3)_6]^{3+}$ vs $[CoF_6]^{3-}$).
- **CFT:** Strong field vs Weak field ligands (Spectrochemical series).

---

## Unit III: Organic Chemistry (33 Marks) - The Giant

### 1. Named Reactions (The Topper's Core)
- **Haloalkanes:** Finkelstein, Swarts, Wurtz-Fittig, Sandmeyer.
- **Alcohols/Phenols:** Reimer-Tiemann, Kolbe’s reaction, Williamson Synthesis.
- **Aldehydes/Ketones:** Rosenmund, Stephen, Etard, Clemmensen, Wolff-Kishner, Aldol, Cannizzaro.
- **Amines:** Hoffmann Bromamide, Gabriel Phthalimide.

### 2. Distinction Tests (Section C/D)
- **Lucas Test:** Primary (slow), Secondary (5 min), Tertiary (immediate turbidity).
- **Tollens' / Fehling's:** Aldehydes (Positive) vs Ketones (Negative).
- **Iodoform Test:** Methyl ketones and alcohols with $CH_3-CH(OH)-$ group.
- **Hinsberg’s Test:** Distinction between 1°, 2°, and 3° amines.

### 3. Mechanisms (High-Frequency 3-Markers)
1. **SN1 vs SN2:** Nucleophilic substitution in haloalkanes.
2. **Dehydration of Ethanol:** To Ethene ($443K$) or Ethoxyethane ($413K$).
3. **Acid-catalyzed hydration of Alkenes.**
4. **Nucleophilic Addition** to Carbonyl groups.

---

## Unit IV: Biomolecules (7 Marks)
- **Carbohydrates:** Glucose (Structure/Reactions), Glycosidic linkage.
- **Proteins:** Amino acids, Peptide linkage, Denaturation.
- **Nucleic Acids:** DNA vs RNA, Nucleosides vs Nucleotides.

---

## High-Yield Strategy (Target 495+)
1. **Physical:** Master the numericals from Nernst Equation and First Order Kinetics.
2. **Inorganic:** Learn the IUPAC rules and CFT logic for Coordination compounds.
3. **Organic:** Create a "Reaction Map". 5 marks usually come from "Conversion" or "Roadmap" questions ($A \to B \to C$).
4. **Graph Analysis:** Study the graphs for Zero/First order reactions and Vapour pressure.

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## Common Board Exam Traps
- **Sign Conventions:** $E^o_{cell}$ calculation errors (Cathode - Anode).
- **Conversions:** Forgetting to change units in Colligative property numericals ($g$ to $kg$).
- **Reagents:** Confusing $LiAlH_4$ (strong reducer) with $NaBH_4$ (mild).
- **IUPAC:** Forgetting the alphabetical order of ligands in coordination naming.

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## Answer Writing Framework
1. **Physical:** State formula $\to$ Substitute with units $\to$ Final Answer boxed.
2. **Inorganic:** Use clear reasoning (e.g., "Due to d-d transition" or "Lanthanoid contraction").
3. **Organic:** Write the full equation with the **Reagent** on the arrow. If asked for a mechanism, show the **Curly Arrows**.

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## Internal Assessment (30 Marks)
- **Volumetric Analysis:** Titration of KMnO4 (8M).
- **Salt Analysis:** Identification of Cation/Anion (8M).
- **Viva:** Be ready for "End point" and "Confirmatory test" logic.