TEACHGYAN • CLASS 10 SCIENCE • NCERT 2026–27
Chapter 2: Acids, Bases and Salts
Detailed Notes • Diagrams • Experiments • Competency • Board Practice
📖 Chapter Explanation
Acids and bases are identified through their properties, indicators and reactions. The chapter develops the pH scale and connects neutralisation, salts and common compounds with laboratory and everyday applications.
🧭 Concept Map
🔬 Core Science Concepts
Acids produce H⁺ ions in aqueous solution while bases produce OH⁻ ions. pH indicates the acidic or basic character of a solution; lower pH means greater acidity, while higher pH indicates greater basicity.
💡 Worked Example / Observation
When hydrochloric acid reacts with sodium hydroxide, HCl + NaOH → NaCl + H₂O. This is a neutralisation reaction.
🖼️ Diagram & Visual Study
Draw and label: a key diagram/process from this chapter. Add arrows showing the sequence or relationships, then write one function/observation beside each labelled part. This page is designed to be paired with textbook figures for visual revision.
⚠️ Common Errors
Do not treat strength and concentration as identical ideas. Also remember that indicators show a range of colours and pH is a scale, not a simple yes/no label.
🧠 Concept-Based MCQs
- A solution with pH 2 is: A) strongly acidic B) neutral C) weakly basic D) strongly basic
- Neutralisation produces: A) salt and water B) metal only C) oxygen only D) carbon only
- Blue litmus in an acid generally turns: A) blue B) red C) green D) black
- Baking soda is commonly known as: A) sodium hydrogen carbonate B) sodium chloride C) calcium carbonate D) sodium hydroxide
Answer Key: 1-A, 2-A, 3-B, 4-A.
📊 Case-Based / Competency
A farmer finds that a soil sample is too acidic. Explain how a suitable basic material can help and why soil pH matters for plant growth.
- Identify the scientific concept.
- Use the relevant equation, process or diagram.
- Explain the observation using scientific reasoning.
- State and justify the conclusion.
🔎 Extension Case
An antacid is used to relieve excess stomach acidity. Students identify the type of reaction involved, explain why a basic substance is useful and connect the idea with pH.
🔥 HOTS & Board Challenge
- Predict what would happen if one condition changed.
- Explain the observation at the particle/cellular/system level where appropriate.
- Correct a plausible misconception and justify your correction.
- Design a simple investigation to test a related idea.
✍️ Exam Practice
- Define the central scientific terms.
- Explain one process using a labelled diagram.
- Write and balance/interpret an equation where applicable.
- Solve a competency-based situation.
- Answer a 5-mark board-style question with reasoning.
🧪 Activity / Experiment Corner
- State the aim.
- List the key materials/conditions.
- Predict the observation.
- Record the result.
- Explain the scientific principle.
📄 Practice Worksheet
- 5 concept checks
- 5 application questions
- 3 diagram/process questions
- 2 case-based questions
- 2 HOTS questions
- 1 board-style challenge
🎯 One-Minute Revision
properties → indicators → acids/bases → pH → neutralisation → salts → common applications
🏆 Mastery Checklist
- ☐ I can explain the concept in my own words.
- ☐ I can draw/interpret the key diagram.
- ☐ I can explain observations scientifically.
- ☐ I can answer competency and case-based questions.
- ☐ I can apply the concept to a new situation.
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Original explanatory study material aligned to NCERT/CBSE topics; textbook passages are not reproduced verbatim.