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Revision Notes
Chemical Thermodynamics — Revision Notes
NIOS · Class 12 · Chemistry
Chemical Thermodynamics revision notes for NIOS Class 12 Chemistry: 4 topics in quick points. Part of the NIOS Class 12 Chemistry syllabus.
45 questions30 flashcards2 formulas & key relations5 concepts
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Key Topics to Revise
1
Basic Terminology in Thermodynamics
- System: The specific part of the universe under study (e.g., reactants and products in a beaker)
- Surroundings: Everything outside the system (e.g., the beaker, lab, atmosphere)
- Isolated System: No exchange of matter OR energy with surroundings (e.g., ideal thermos flask)
2
Exothermic and Endothermic Reactions
- Exothermic reactions RELEASE heat to surroundings — the system loses energy, so ΔH is NEGATIVE
- Endothermic reactions ABSORB heat from surroundings — the system gains energy, so ΔH is POSITIVE
- Examples of exothermic: Combustion of fuels, neutralization reactions, adding water to quicklime (CaO)
3
Thermochemical Equations
- Thermochemical equations specify: balanced chemical equation + physical states + ΔH value
- Physical states are represented as: (g) = gas, (l) = liquid, (s) = solid, (aq) = aqueous solution
- Allotropic forms must be specified: C(graphite) or C(diamond)
4
First Law of Thermodynamics and Internal Energy
- First Law: Energy can neither be created nor destroyed; total energy of universe (or isolated system) is constant
- Mathematical form: ΔU = q + w (IUPAC convention)
- ΔU = change in internal energy, q = heat absorbed BY the system, w = work done ON the system
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Full NotesKey Concepts
A system is the partState functions depend only on initialExtensive properties depend on system sizeExothermic reactions release heat to surroundingsEnergy cannot be created or destroyed
Frequently Asked Questions
What are the important topics in Chemical Thermodynamics for NIOS Class 12 Chemistry?
Key topics in Chemical Thermodynamics include Basic Terminology in Thermodynamics, Exothermic and Endothermic Reactions, Thermochemical Equations, First Law of Thermodynamics and Internal Energy. Study these first, then practise questions on each for the NIOS Class 12 board exam.
How should I revise Chemical Thermodynamics for the NIOS Class 12 board exam?
Learn the core ideas first, then work through the 45 practice questions on Chemical Thermodynamics. Revise definitions regularly and use flashcards for quick recall before the exam.
Sources & Official References
Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.
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