Thermodynamics — Class 11 Chemistry (Samacheer Kalvi)
TN State Board (Samacheer Kalvi) Class 11 Chemistry, Chapter 7. Internal energy, enthalpy, Hess's law and Gibbs energy.
1. About this chapter
This chapter covers Thermodynamics as part of the Class 11 Samacheer Kalvi Chemistry curriculum. It deals with internal energy, enthalpy, hess's law and gibbs energy and builds conceptual understanding essential for the TN HSC Public Exam.
By the end of this chapter, students will be able to:
- Define and calculate enthalpy changes
- Apply Hess's law
- Use ΔG to predict reaction spontaneity
2. Key concepts
- Concept 1: Define and calculate enthalpy changes.
- Concept 2: Apply Hess's law.
- Concept 3: Use ΔG to predict reaction spontaneity.
3. Important terms and formulas
| Term / Formula | Description |
|---|---|
| Define and calculate enthalpy… | Define and calculate enthalpy changes |
| Apply Hess's law… | Apply Hess's law |
| Use ΔG to predict… | Use ΔG to predict reaction spontaneity |
4. Worked examples
Example 1. Applying a key concept from this chapter.
Solution: Identify the relevant principle → apply the formula or rule → state the answer with correct units.
Example 2. A typical exam-style question on thermodynamics.
Solution: Break the problem into steps, use the appropriate formula and verify the answer.
5. Common mistakes
- Mistake: Skipping units or forgetting to state them. Fix: Always write units alongside every quantity and answer.
- Mistake: Confusing similar terms or concepts in this chapter. Fix: Make a comparison table of the terms during revision.
6. Practice (exam-style)
- Define the main term or principle covered in Chapter 7.
- Give two real-life examples related to thermodynamics.
- Solve a short numerical or descriptive question from this chapter.
- State one important formula and explain each symbol.
7. Answer key (hints)
- Refer to section 2 (Key concepts) above for the definition.
- Examples should be drawn from daily experience and local context.
- Apply the formula from section 3, show all steps clearly.
- Formula with units — refer to the textbook glossary for symbol meanings.
8. Quick revision
- Class 11 Chemistry — Chapter 7: Thermodynamics.
- Core idea: Internal energy, enthalpy, Hess's law and Gibbs energy.
- Key outcomes: Define and calculate enthalpy changes; Apply Hess's law; Use ΔG to predict reaction spontaneity.
- Always revise diagrams / tables from the Samacheer Kalvi textbook before the exam.
