Master all 11 core chemical reactions, balancing rules, and essential definitions in under 5 minutes before entering the board exam hall.
Designed for last-minute review before the exam. Covers 7 core definitions, 11 key balanced reactions, and 4 common student traps.
1. 7 Core Definitions Checklist
Breaking of old chemical bonds and formation of new bonds with new properties.
Equal number of atoms of each element on reactants (LHS) and products (RHS) to satisfy mass conservation.
Two or more reactants combine to form a single product ($A + B \to AB$).
A single compound breaks down into two or more simpler products via heat, light, or electricity.
A more reactive metal displaces a less reactive metal from its aqueous salt solution.
Mutual exchange of ions between two ionic compounds, often forming a precipitate.
Simultaneous occurrence of oxidation (gain of O / loss of H) and reduction (loss of O / gain of H).
2. 11 Core Chemical Reactions Summary Table
3. Visual Mind Map Tree
├── 1. Combination ($A + B \to AB$) ➔ [Ex: $\text{CaO} + \text{H}_2\text{O} \to \text{Ca(OH)}_2$]
├── 2. Decomposition ($AB \to A + B$)
│ ├── (i) Thermal ➔ [Heating $\text{FeSO}_4$, $\text{CaCO}_3$, $\text{Pb(NO}_3)_2$]
│ ├── (ii) Electrolytic ➔ [Water electrolysis, $\text{H}_2:\text{O}_2 = 2:1$]
│ └── (iii) Photolytic ➔ [$\text{AgCl}$, $\text{AgBr}$ turning grey in sunlight]
├── 3. Displacement ($A + BC \to AC + B$) ➔ [$\text{Fe} + \text{CuSO}_4 \to \text{FeSO}_4 + \text{Cu}$]
├── 4. Double Displacement ($AB + CD \to AD + CB$) ➔ [$\text{BaSO}_4$ white precipitate]
└── 5. Redox (Oxidation + Reduction) ➔ [$\text{CuO} + \text{H}_2 \to \text{Cu} + \text{H}_2\text{O}$]
4. Top 4 Common Student Traps & Pitfalls
Do not write merely $\text{Fe}_2\text{O}_3$. The exact formula is Hydrated Ferric Oxide ($\text{Fe}_2\text{O}_3\cdot x\text{H}_2\text{O}$), where ‘$x$’ denotes variable water molecules.
In water electrolysis: Hydrogen (2 volumes) collects at the Cathode (-), while Oxygen (1 volume) collects at the Anode (+).
Respiration is exothermic (energy is liberated). Photosynthesis is endothermic (solar light energy is absorbed).
The substance that gets reduced is the oxidizing agent. The substance that gets oxidized is the reducing agent.
5. Confirmatory Gas Identification Tests
6. NCERT Master Color-Change Summary Sheet
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Revision Notes / संक्षिप्त नोट्स
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