Acids, Bases & Salts Mind Map For 10th Class Science Board Exam

Acids, Bases & Salts: The CBSE Science 10th class board exam 2026 is scheduled on 25 February 2026. Students are now in the most critical phase of preparation. Acids, Bases & Salts is an important and frequently asked chapter, often tested through definitions, chemical reactions, pH-based numericals, and practical applications.

To support effective last-minute preparation, this mind map-based explanation is designed to help students easily connect key concepts such as properties, reactions, the pH scale, indicators, dilution of acids, and commonly used salts—crucial for excelling in the Science board exam 2026.

Quick Revision Tip:

• Revise high-weightage reactions first.

• Focus on pH concepts and common salts.

• Use mind map diagrams for visual memory

Chapter-wise Mind Map Series: Acids, Bases & Salts

This mind map series can help students secure good marks in the Science 10th class board exam 2026. Many students find it tricky due to interconnected reactions, pH, and real-life applications. A simple, organised approach using mindmap can make learning and revision effective.

This mind map video explains the Acids, Bases & Salts chapter in a clear, interconnected format, helping students quickly grasp key concepts, remember important reactions, pH rules, and common salts, and revise confidently for the Science 10th class board exam 2026.

Acids, Bases & Salts

Acids, bases, and salts form the cornerstone of chemistry, influencing countless natural phenomena and industrial processes. Understanding their properties, reactions, and interactions is crucial for grasping chemical principles and appreciating their impact on daily life. This discussion provides a comprehensive overview of these essential chemical compounds, from their basic characteristics to their practical applications.

To know this in more easy way you can watch the Mind Map Series for Class 10th for Acids, Bases & Salts Chapter

Physical Properties of Acids and Bases

The physical properties of acids and bases are important for the 10th Science board exam, as the MCQs and short answer questions can arise from this. Students must learn all these properties and learn through mindmap. 

Here is a summary of the physical properties of acids and bases:

CAUTION: Never taste or touch acids and bases to identify them. This can be extremely dangerous due to their corrosive nature.

2-Minute Quick Recap:

• Acids → sour, can corrode, and conduct electricity in water.

• Bases → bitter, slippery, corrode, conduct electricity.
  Memory Trick: TTCC → Taste, Touch, Corrosive, Conductivity

Classification of Acids Based on the Source

Acids are classified into two main categories based on their origin:

1. Organic Acids

• Source: Obtained from living sources like plants and animals.

• Examples:

• Citrus Fruits (lemon, orange): Contain primarily Citric Acid, but also Ascorbic Acid (Vitamin C).

• Tamarind (इमली): Contains Tartaric Acid.

• Tomato (टमाटर): Contains Oxalic Acid.

• Vinegar (सिरका): A dilute solution of Acetic Acid (typically 5-8% acetic acid in water).

• Nettle Sting / Ant Sting / Bee Sting: Inject Formic Acid (or Methanoic Acid).

• Apple: Contains Malic Acid.

• Curd (दही): Contains Lactic Acid.

2. Inorganic (or Mineral) Acids

• Source: Obtained from non-living sources like rocks and minerals.

• Examples: Hydrochloric Acid (HCl), Sulfuric Acid (H₂SO₄), Nitric Acid (HNO₃), Carbonic Acid (H₂CO₃), Phosphoric Acid (H₃PO₄).

To know this in more easy way you can watch the Mind Map Series for Class 10th for Acids, Bases & Salts Chapter

2-Minute Quick Recap

• Organic → Living sources (Fruits, Curd, Stings)

• Inorganic → Minerals, lab acids

Memory Mnemonic: C-T-T-V-A-C → Citrus, Tamarind, Tomato, Vinegar, Apple, Curd

How to Identify an Acid or a Base: Indicators

Since tasting or touching is unsafe, chemical substances called indicators are used. Indicators signal the presence of an acid or a base by undergoing a sharp change in their colour or smell.

1. Indicators that Change Colour

2. Olfactory Indicators (Indicators that Change Smell)

These indicators are useful for visually impaired individuals, identifying acidic or basic solutions through a change in their characteristic smell.

• Onion-treated cloth strips: The characteristic smell of onion persists in an acidic solution but disappears in a basic solution.

• Vanilla Essence: The smell of vanilla persists in an acidic solution but disappears in a basic solution.

• Clove Oil (लौंग का तेल): The smell of clove persists in an acidic solution but disappears in a basic solution.

Common Mistakes: Confusing turmeric vs litmus colour change.

Chemical Properties of Acids

Acids show characteristic chemical behaviour by reacting with metals, bases, metal carbonates, and metal oxides, usually producing salts, water, and gases.

1. Reaction of Metals with Dilute Acids

• General Reaction: Metal + Dilute Acid → Salt + Hydrogen Gas (H₂)

• Condition: Occurs with metals more reactive than hydrogen in the acid (e.g., Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g)).

• Reaction Type: Displacement Reaction.

• Observation: Hydrogen gas is evolved with effervescence.

• Test for Hydrogen Gas: A burning candle or matchstick extinguishes with a characteristic "squeaky pop" sound. Hydrogen gas is combustible but not a supporter of combustion.

2. Reaction of Metal Carbonates and Metal Hydrogen Carbonates with Acids

• General Reaction: Metal Carbonate/Bicarbonate + Acid → Salt + Water + Carbon Dioxide (CO₂)

• Reaction Type: Double Displacement Reaction, specifically a Gas-Forming Reaction.

• Example: CaCO₃(s) + 2CH₃COOH(aq) → (CH₃COO)₂Ca(aq) + H₂O(l) + CO₂(g) (since H₂CO₃ decomposes).

• Observation: Carbon dioxide gas is evolved with effervescence.

• Test for Carbon Dioxide Gas (The Limewater Test):

1. Short Duration: CO₂ gas turns limewater (calcium hydroxide, Ca(OH)₂) milky or turbid due to insoluble calcium carbonate (CaCO₃).
   Ca(OH)₂(aq) + CO₂(g) → CaCO₃(s) + H₂O(l)

2. Long Duration (Excess CO₂): Excess CO₂ makes the solution colorless again by forming soluble calcium hydrogen carbonate (Ca(HCO₃)₂).
   CaCO₃(s) + H₂O(l) + CO₂(g) [excess] → Ca(HCO₃)₂(aq)

3. Reaction of Basic Metal Oxides with Acids

• General Reaction: Metal Oxide (Basic) + Acid → Salt + Water

• Nature of Reactants: Many metal oxides and hydroxides are basic in nature.

• Reaction Type: Neutralization Reaction.

• Example: CuO(s) [Black] + 2HCl(aq) [Colorless] → CuCl₂(aq) [Blue-Green] + H₂O(l) (CuO acts as a base).

Reactions of Bases

Bases show characteristic reactions with amphoteric metals, acidic oxides, and acids in aqueous solutions, helping explain neutralization, pH behavior, and safe chemical practices.

1. Reaction of Amphoteric Metals with Alkalis

• Amphoteric Metals: React with both acids and bases (e.g., Aluminum (Al) and Zinc (Zn)).

• Alkalis: Bases soluble in water.

• General Reaction: Amphoteric Metal + Alkali → Salt + Hydrogen Gas (H₂)

• Example: Zn(s) + 2NaOH(aq) → Na₂ZnO₂(aq) [Sodium Zincate] + H₂(g)

To know this in more easy way you can watch the Mind Map Series for Class 10th for Acids, Bases & Salts Chapter

2. Reaction of Non-metallic Oxides with Bases

• Nature of Reactants: Many non-metallic oxides (e.g., CO₂, SO₂) are acidic in nature.

• General Reaction: Non-metallic Oxide (Acidic) + Base → Salt + Water

• Reaction Type: Neutralization Reaction.

• Example 1: CO₂(g) + Ca(OH)₂(aq) → CaCO₃(s) [White Precipitate] + H₂O(l)

• Example 2: SO₃(g) + 2NaOH(aq) → Na₂SO₄(aq) + H₂O(l)

2-Minute Quick Recap:

• Acids react with metals, carbonates, oxides → H₂, CO₂, neutralization

• Bases react with amphoteric metals, acidic oxides

Memory Tip: H₂ = Squeaky Pop, CO₂ = Limewater Milky

The Role of Water in the Dissociation of Acids

Acids exhibit their acidic character only in the presence of water.

• Experiment: Dry HCl gas produced from NaCl(s) + H₂SO₄(conc) → NaHSO₄(s) + HCl(g) does not change dry blue litmus paper. However, it turns moist (wet) blue litmus paper red.

• Explanation: In water, HCl dissociates to release H⁺ ions. These H⁺ ions combine with water molecules to form Hydronium ions (H₃O⁺).
  HCl(g) + H₂O(l) → H₃O⁺(aq) + Cl⁻(aq)

• Conclusion: The acidic character of acids is due to the presence of Hydronium ions (H₃O⁺), formed only in aqueous solutions.

• Use of a Guard Tube: A guard tube containing anhydrous calcium chloride (CaCl₂) ensures the HCl gas is completely dry, preventing premature reaction with moisture.

Dilution of Acids

Diluting concentrated acids requires extreme caution due to their highly exothermic nature.

Common Mistake: Students often reverse order → burns and accidents

pH: Acidity and Alkalinity

The Concept of pH

• pH stands for "power of hydrogen" ('p' from German 'Potenz').

• The pH scale (typically 0 to 14 at 25°C) measures the concentration of hydrogen ions (H⁺) or hydronium ions (H₃O⁺) in a solution.

Interpreting the pH Scale (at 25°C)

• pH < 7: The solution is Acidic (H⁺(aq) > OH⁻(aq)).

• pH = 7: The solution is Neutral (H⁺(aq) = OH⁻(aq)).

• pH > 7: The solution is Basic (or Alkaline) (H⁺(aq) < OH⁻(aq)).
  

Universal Indicator

A Universal Indicator is a mixture of several indicators that displays a spectrum of colors at different pH values, revealing the strength of an acid or base.

• Memory Tip: A way to remember the color progression from neutral towards acidic is by a variation of the rainbow colors: Blue → Green (Neutral) → Yellow → Orange → Red.

• Green (pH ≈ 7): Neutral (e.g., Pure Water)

• Yellow/Orange (pH ≈ 2-6): Weakly to Moderately Acidic (e.g., Lemon Juice, Gastric Juice)

• Red (pH ≈ 0-1): Strongly Acidic

• Blue/Violet (pH ≈ 8-14): Basic (e.g., Milk of Magnesia, NaOH solution)

pH and Its Importance in Everyday Life

pH explains how acidic or basic substances affect common daily situations and helps in choosing the right method to neutralize their effects.

Strong vs. Weak Acids and Bases

The strength of an acid or base depends on its degree of dissociation into ions in water.

Comparative Structure: Strong vs. Weak Electrolytes

• Memory Tip: Common Strong Acids and Bases to remember for the course curriculum are:

• Strong Acids: Sulfuric Acid (H₂SO₄), Nitric Acid (HNO₃), Hydrochloric Acid (HCl), Hydrobromic Acid (HBr), Hydroiodic Acid (HI), Perchloric Acid (HClO₄), Chloric Acid (HClO₃). (All other acids are generally considered weak.)

• Strong Bases: Sodium Hydroxide (NaOH), Potassium Hydroxide (KOH), Calcium Hydroxide (Ca(OH)₂), Magnesium Hydroxide (Mg(OH)₂).

• Weak Bases: Ammonium Hydroxide (NH₄OH), Copper Hydroxide (Cu(OH)₂).

Introduction to Salts

Introduction to Salts: Salts are ionic compounds formed by the neutralization of acids and bases, and their aqueous solutions can be acidic, basic, or neutral depending on the nature of the parent acid and base.

Definition

Salts are ionic compounds composed of a positively charged ion (Cation) and a negatively charged ion (Anion). They are electrically neutral, as the total positive charge equals the total negative charge (e.g., in NaCl, Na⁺ has +1 and Cl⁻ has -1).

pH of Salt Solutions

The pH of a salt solution depends on the strength of the acid and base from which it was formed:

• Strong Acid + Strong Base → Forms a Neutral Salt with pH = 7.

• Weak Acid + Weak Base → Also forms a Neutral Salt with pH = 7.

• Strong Acid + Weak Base → Forms an Acidic Salt with pH < 7.

• Strong Base + Weak Acid → Forms a Basic Salt with pH > 7.

Common Salts and Their Properties

1. Common Salt (Table Salt)

• Chemical Name: Sodium Chloride

• Chemical Formula: NaCl

• Sources: Seawater (by evaporation) and Rock Salt (solid mineral deposits).

• Importance: Essential for bodily functions (e.g., maintaining blood pressure), and a raw material for chemicals like Sodium Hydroxide and Bleaching Powder.

2. Caustic Soda (Lye)

• Chemical Name: Sodium Hydroxide

• Chemical Formula: NaOH

• Manufacturing: The Chlor-alkali Process This process involves the electrolysis of concentrated aqueous NaCl solution (brine).

• At Anode (Positive Terminal): 2Cl⁻(aq) → Cl₂(g) + 2e⁻ (Chlorine gas formed)

• At Cathode (Negative Terminal): 2H⁺(aq) + 2e⁻ → H₂(g) (Hydrogen gas formed from water's dissociation)

• Final Products: Chlorine gas (Cl₂) at the anode, Hydrogen gas (H₂) at the cathode, and Sodium Hydroxide (NaOH) solution near the cathode. NaOH is the main product, while H₂ and Cl₂ are by-products.

• Uses of Chlor-alkali Products:

• Caustic Soda (NaOH): Soaps, detergents, degreasing metals, drain cleaner.

• Hydrogen (H₂): Rocket fuel, ammonia for fertilizers, margarine production.

• Chlorine (Cl₂): Pesticides, PVC, CFCs, disinfectant in swimming pools.

3. Bleaching Powder

• Chemical Name: Calcium Oxychloride

• Chemical Formula: CaOCl₂

• Manufacturing: Reacting Chlorine gas (from Chlor-alkali process) with dry slaked lime (Ca(OH)₂).
  Ca(OH)₂(s) + Cl₂(g) → CaOCl₂(s) + H₂O(g)

• Uses: Bleaching cotton/linen, oxidizing agent, disinfecting drinking water.

4. Baking Soda

• Chemical Name: Sodium Hydrogen Carbonate or Sodium Bicarbonate.

• Chemical Formula: NaHCO₃

• Manufacturing: Solvay Process (Ammonia-Soda Process)
  Baking soda is an intermediate product.
  NaCl + H₂O + NH₃ + CO₂ → NaHCO₃ + NH₄Cl

• Uses of Baking Soda: Antacid medicines, soda-acid fire extinguishers, component in Baking Powder.

• Baking Soda vs. Baking Powder:

• Baking Soda: Pure Sodium Hydrogen Carbonate (NaHCO₃).

• Baking Powder: A mixture of Baking Soda (NaHCO₃), a mild edible dry acid (e.g., Tartaric Acid), and Corn Starch. Corn starch prevents premature reaction. Both produce CO₂ for leavening.

5. Washing Soda

• Chemical Name: Sodium Carbonate Decahydrate

• Chemical Formula: Na₂CO₃·10H₂O

• Manufacturing (Solvay Process Continuation):

1. Thermal Decomposition of Baking Soda: 2NaHCO₃(s) --(Heat)--> Na₂CO₃(s) + H₂O(g) + CO₂(g) (forms Soda Ash).

2. Recrystallization: Soda ash (Na₂CO₃) is recrystallized from water to form Washing Soda (Na₂CO₃·10H₂O), incorporating water of crystallization.

• Concept: Water of Crystallization

• Definition: The fixed number of water molecules chemically attached to one formula unit of a salt in its crystalline state.

• Function: Imparts a fixed geometric shape (crystal structure) and often, characteristic color.

• Uses of Washing Soda: Glass, soap, and paper industries, removing permanent hardness of water, manufacturing Borax, domestic cleaning agent.

6. Plaster of Paris (POP)

• Chemical Name: Calcium Sulfate Hemihydrate

• Chemical Formula: CaSO₄·½H₂O or (CaSO₄)₂·H₂O.

• Manufacturing: Heating Gypsum (CaSO₄·2H₂O) at 373 K (100°C).
  CaSO₄·2H₂O (Gypsum) --(100°C)--> CaSO₄·½H₂O (POP) + 1½H₂O(g)

• Property: Setting of Plaster of Paris

• When mixed with water, POP sets into a hard, solid mass which is Gypsum.

• CaSO₄·½H₂O (POP) + 1½H₂O(l) → CaSO₄·2H₂O (Gypsum)

• Caution: POP must be stored in a moisture-proof container to prevent it from absorbing moisture and setting prematurely.

• Uses: Setting fractured bones, making toys and decorative items, creating smooth surfaces on walls/ceilings.

Memory Trick: Baking Soda = NaHCO₃ (single), Baking Powder = mixture + starch

2-Minute Quick Recap: Salt → Formula → Use → Source

Smart Revision Tips for Acids, Bases & Salts – Class 10 Science Board Exam 2026

Acids, Bases & Salts is a high-scoring and concept-driven chapter in the Science 10th class board exam 2026. With the board exam scheduled on 25 February 2026, students should focus on smart, structured revision rather than rote learning. The right revision strategy helps in remembering reactions, avoiding common mistakes, and writing accurate answers in the exam.

• Revise the chapter using mind maps to connect properties, reactions, pH, indicators, and common salts

• Focus first on high-weightage areas like chemical reactions, pH scale, indicators, and common salts

• Memorise key reactions with conditions and observations (H₂ squeaky pop, CO₂ limewater test)

• Practice pH-based numericals and reasoning questions from NCERT

• Revise uses, preparation, and formulas of common salts (NaCl, NaOH, CaOCl₂, NaHCO₃, Na₂CO₃·10H₂O, POP)

• Use 2-minute quick recaps and memory tricks for fast last-day revision

• Solve previous year board questions and NCERT in-text questions to understand exam patterns

Exam Tip: Always write balanced chemical equations, mention gas tests, and underline keywords to improve presentation.

Common Mistakes Students Make in Acids, Bases & Salts Chapter

Many students lose easy marks in Acids, Bases & Salts not because the chapter is difficult, but due to conceptual confusion, careless writing, and ignoring NCERT statements. Avoiding these common mistakes can significantly boost your Science board exam 2026 score.

• Confusing acidic, basic, and neutral pH ranges on the pH scale

• Writing reactions without balancing or missing state symbols

• Mixing up litmus and turmeric colour changes

• Forgetting the rule: Add acid to water, never water to acid

• Not mentioning tests for gases (H₂ squeaky pop, CO₂ limewater milky)

• Confusing baking soda with baking powder

• Writing incomplete answers for uses, preparation, or properties of salts

• Ignoring water of crystallization concept in washing soda and POP

• Skipping diagrams, flowcharts, or stepwise explanations where required

Board Reminder: Most answers are strictly checked as per NCERT wording, so avoid extra assumptions and stick to textbook terminology.