CBSE Class 10 Science Revision Notes Chapter 2

CBSE Class 10 Science Revision Notes Chapter 2 – Acids, Bases, and Salts

The Class 10 Science Chapter 2 – Acids, Bases, and Salts is an important chapter that every student should study properly to score well in the final examinations. A good score is required in the board examination to choose the stream for career development. Hence, it is essential for students to rigorously prepare for their examinations and ensure the security of their future. The Class 10 Chapter 2 Science Notes explains the topic of acids, bases, salts, and chemical changes related to it. With so much to learn and understand, students are required to revise their notes on a regular basis. 

In order to simplify it for students, Extramarks provides a comprehensive list of Chapter 2 Science Class 10 Notes which can be accessed from the official website. These revision notes are prepared by experts according to the guidelines of CBSE. Simple and easy language is used to express the required information through the Chapter 2 Science Class 10 Notes. Apart from revision notes, students can also refer to the CBSE sample papers, CBSE previous year question papers, etc to understand the board examination pattern of Class 10. One can access the Class 10 CBSE revision notes from the website of Extramarks. 

CBSE Class 10 Science Revision Notes for the Year 2022-23

Sign Up and get complete access to CBSE Class 10 Science Chapterwise Revision Notes for the following chapters:

CBSE Class 10 Science Revision Notes
Sr No. Chapters
1 Chapter 1 – Chemical Reactions and Equations
2 Chapter 2 – Acids, Bases and Salts
3 Chapter 3 – Metals and Non-metals
4 Chapter 4 – Carbon and Its Compounds
5 Chapter 5 – Periodic Classification of Elements
6 Chapter 6 – Life Processes
7 Chapter 7 – Control and Coordination
8 Chapter 8 – How do Organisms Reproduce?
9 Chapter 9 – Heredity and Evolution
10 Chapter 10 – Light Reflection and Refraction
11 Chapter 11 – Human Eye and Colourful World
12 Chapter 12 – Electricity
13 Chapter 13 – Magnetic Effects of Electric Current
14 Chapter 14 – Sources of Energy
15 Chapter 15 – Our Environment
16 Chapter 16 – Management of Natural Resources

CBSE Class 10 Science Chapter 2 – Acids, Bases, and Salts Revision Notes – Free PDF Download – (Add revision notes PDF)

Class 10 Science Chapter 2 Notes PDF Download


While bases are bitter and turn the red litmus blue, acids have a sour flavour and do the opposite, turning the blue litmus red. Turmeric is one such natural indicator, along with litmus. To test for acids and bases, we can also use synthetic indicators like phenolphthalein and methyl orange. We will learn about the interactions between acids and bases in this chapter, as well as many other fascinating phenomena that we see daily. The purple dye known as litmus solution, which is frequently used as an indicator, is obtained from lichen, a plant belonging to the family division Thallophyta. Purple is the colour of the litmus solution when it is neither acidic nor basic. Many other natural materials, including red cabbage leaves, turmeric, and the pigmented petals of some flowers, can be used to determine if an acid or base is present in a solution. These are referred to as acid-base indicators or occasionally just indicators.

General Properties of Acids:

The general properties of acids are as follows: 

  • They taste sour. 
  • Acids can react with metals such as magnesium, zinc, etc. to liberate the hydrogen gas. 
  • Acids can change the color of litmus from blue to red. 
  • Acids can conduct electricity. 

General Properties of Bases:

The general properties of bases are as follows: 

  • Bases have a soapy feel. 
  • They can burn the skin. 
  • The common examples of bases are soaps and detergents. 
  • Caustic soda NaOH. Caustic potash KOH, Milk of Magnesia Mg (OH)2, Liquor ammonia NH3, washing powder, and toothpaste are most commonly found in laboratories and in daily life. 


Concentrated and dilute acids: 

An acid containing less quantity of water is known as concentrated acid. Whereas by diluting a concentrated acid with water, one can obtain a dilute acid. 

Dissolving acids and bases in water: 

The process of dissolving the acids and bases in water is exothermic. This reaction generates a lot of heat. So one should always put acid in water by taking precautions. The acid should be slowly added to the water while swirling constantly. 

What happens when an acid is dissolved in water? 

An acid contains hydrogen ions so the stronger an acid is, the more hydrogen ions it contains. A change that creates H+ ions when dissolved in water is a suitable definition of an acid. The hydrogen ions cannot exist by themselves; they will exist only after combining with water molecules. 

H+ + H2O→ H3O+

What is the Strength of Acid Solutions?

Strong Acid:

  • An acid that dissociates completely or nearly completely in water is known as a strong acid. 
  • In strong acids, all hydrogen ions react with water molecules to form hydronium ions. Examples are nitric acid, sulphuric acid, and hydrochloric acid. 
  •  HCl(aq)→H+(aq)+Cl(aq) 



  • H2SO4(aq)→2H+(aq)+SO42-(aq)

Nitric Acid 

Weak Acid: 

  • An acid that dissolves partially when dissolved in water is known as a weak acid. 
  • Examples of weak acids: acetic acid, formic acid, carbonic acid, etc. 
  • CH3COOH(aq)→CH3COO−(aq)+H+(aq) 



  • HCOOH(aq)→HCOO(aq)+H+(aq)



  • H2CO3(aq)→H+(aq)+HCO3−(aq)



Acid Reactions of Metallic Oxides:

Basic oxides in action: 

Basic oxides react with acid to generate salt and water. When these oxides react with acids, they get neutralized. 

  • Na2O(s) + 2HCl(aq)→2NaCl(aq)+H2O(l)
  • PbO(s)+2HNO3(aq)→Pb(NO3)2(aq)+H2O(l) 
  • CuO(s)+H2SO4(aq)→CuSO4(aq)+H2O(l)

Action with basic hydroxides: 

Acids undergo neutralization and react with basic hydroxides to form salt and water. 

  • 2KOH(aq)+H2CO3(aq)→K2CO3(aq)+2H2O(l)
  • 3NaOH(aq)+H3PO4(aq)→Na3PO4(aq)+3H2O(l)
  • NH40H(aq)+H2S04(aq)   →(NH4)2S04(aq) + 2H2O(l)

Nonmetallic salts and base reaction: 

The base calcium hydroxide reacts with carbon dioxide to create salt with water. 


Class 10 Science Chapter 2 Notes PDF Download

Notes of Chapter 2 Science Class 10- Acids, Bases, and Salts

The Class 10 Science Chapter 2 Notes will help students learn about acids, bases, and salts in detail. In addition, the CBSE revision notes provide information about the various properties, chemical reactions and important laws related to the topic. Here’s a quick overview of the notes:


  • Acids are compounds producing hydrogen ions when dissolved in water.
  • Acids are sour in taste and turn blue litmus red. 
  • They can be found in different fruits and vegetables. 


  • They are the chemical opposites of acids and accept the positive ions when dissolved wait water. 
  • Bases are bitter in taste and turn red litmus blue. 


  • When acids react with the base they form salts as the reaction takes place. 
  • They have a unique family containing different types of salts. 

The revision notes of Class 10 Chapter 2 Science Notes discuss the important definitions, laws, and different concepts of chemical equations. 

The important topics covered in the notes are as follows: 

  • Electrolytes 
  • Acid based reactions 
  • Neutralisation 
  • Indicators 
  • PH scale 
  • The theories of acids and bases 
  • Definition and properties of salts 
  • Definition and properties of bases 
  • Definition and properties of acids 


  • Hydroxides and metal oxides are known as bases. Examples of bases are sodium hydroxide, magnesium oxide, calcium oxide, copper oxide, etc. 
  • Some of the bases are water-soluble, forming hydroxyl ions when they dissolve in water. Example: NaOH(aq)→Na+(aq)+OH(aq)
  • All alkalis are bases that dissociate in water to produce negative ions. 
  • The most prevalent ions are potassium hydroxide, calcium hydroxide, etc. 
  • Strong base/alkali: When a base is dissolved in water, the concentration of ions determines its strength. It dissociates completely in the water to produce a concentration of hydroxyl ions. Example: NaOH, KOH, & LiOH
  • Weak base/alkali: A weak base is one that partially dissociates in water. Examples are calcium hydroxide and ammonium hydroxide. 
  • Reactions of bases: Bases combine with ammonium salts to form ammonia. 


  • The negative logarithm of hydrogen ion concentration in moles is used to calculate the pH of a solution. 

pH= – log [H+(aq)]

  • Indicators are the markers through which one can distinguish between acids and bases. They are compounds that can change colour when exposed to acidic, basic or neutral media. 


  • Salts are made of acid and a base. Positive ions are cations and negative ions are known as anions. 
  • Family of salts: Given below are various types of salts.

Sodium chloride: Common salt is also known as sodium chloride which is most widely used in households. The main source is seawater. Rock salt is a form of sodium chloride. Evaporation of seawater is the most common method to form sodium chloride. 

Sodium carbonate: It is available in both anhydrous and hydrated salt. Washing soda is the name used for dehydrated salt. The manufacture of sodium carbonate is through a Solvay process. They are used to manufacture glass and used for washing purposes, household cleansing agents, paper industries, textile industry, etc. 

The Solvay process can also be referred to as the ammonia-soda process.

Sodium hydrogen carbonate: It is also known as sodium bicarbonate or baking soda. It decomposes when heated, releasing carbon dioxide bubbles. They are used in baking, fire extinguishers, mild antiseptic and laboratory agents, etc. 

Sodium hydroxide: It is referred to as caustic soda. The Chlor alkali process is used to manufacture sodium hydroxide. The anode produces chlorine gas while the cathode emits hydrogen gas. It is used as a reagent, in commercial cotton, oil industries, rubber reclamation, manufacture of soda lime, etc. 

Plaster of Paris: It is calcium sulphate with half a molecule of water per molecule of salt. It is used for constructions, surgeries, sculptures, dentistry procedures, etc. 

Benefits of Class 10 Chapter 2 Science Notes:

The benefits of the Chapter 2 Science Class 10 Notes are given below:

  • The revision notes will help students in understanding the basic concepts of the topic. They can easily clear their doubts by studying the notes of Chapter 2, as simple language is used. 
  • The notes are created according to the CBSE syllabus and contain numerous examples and charts that will help candidates score well in the examination. 
  • All the topics of the chapter are given in a nutshell which can be a good source of revision for students before the examination. 


Class 10 Science Chapter 2 Notes are easy to understand and students can rely on them for their board examination preparation. Candidates should read the information provided in the notes thoroughly to gain information on every topic. The notes are created by the experts with special emphasis on the important questions and topics. In addition, Extramarks recommends that students must read the NCERT books properly before the examinations. 

FAQs (Frequently Asked Questions)

1. Which is the strongest acid?

A1. Fluoroantimonic acid is the strongest acid with 13.3 pH. It is made of hydrogen fluoride and antimony pentafluoride that contains different cations and anions. You can have access to more information about Chapter 2, CBSE extra questions, and other necessary data from the Extramarks website.