NCERT Class 10th Science Ch-1 Notes (Chemical Reaction and Equation)


NCERT Class 10th Science Ch-1 Notes: The main aim of this Chapter is to teach you about the different Chemical reactions which are happening in your Surroundings or Inside your Body and how to Understand them and get convert them in the form of Equations.

Importance of this chapter in our Day to day Life:

After reading this chapter you can Read write and balance the Chemical reactions and their Equations and this will help you to understand the Basic Phenomena Behind the Chemical Reactions.

Eg:- Some Physical and the Chemical Changes in our Day to day life

 milk is left at room temperature during summers.
 an iron tawa/pan/nail is left exposed to a humid atmosphere.
 grapes get fermented.
 food is cooked.
 food gets digested in our bodies.
 we respire.

Motivation Before Starting:

Chemistry is not a Rocket Science…! Okay, this is Very easy to Understand. So, Don’t worry about Chemistry. And One More thing that you don’t have to memorize Chemistry Because Chemistry Itself Says:- CHEM—IS—-TRY.

Questions Related to chapter Activities and their Explanation:

Chemical Reaction and Equation class 10th science:-

Physical Changes vs Chemical Changes:-

Physical Changes:- Like H2O, It can be any form… Solid-liquid or gas. But there is no chemical change, its physical change will change according to the temperature but the Chemical Formula and Molecules will be the same.

what is Chemical Changes/Reaction: (A very common, popular and Exiciting reaction) Ex: H2 + O2—–> H2O. Like Hydrogen is a Fuel whereas Oxygen supports Combustion. But After Reaction, the compound formed is Water, that helps to control Fire. This is a Chemical change where two elements or compounds combine together to form another compound.

What is Chemical Reaction?

Ans:- This is a Process in which one or more substances react to form a Substance whose properties are fully Different form the reactants.

What is Reactants?

Ans:- The Substance which is at the left-hand side of any Reaction or takes part in any Chemical reaction is Known as reactants.

What are Products?

Ans:- The Substance that formed during the Chemical Reaction are called Products.

What is word Equation?

When we explain any chemical reaction in a form of words then it is Known as word Equation. Example:- When we heat Magnesium in the presence of oxygen the Magnesium Oxide is Formed.

Burning of Magnesium: See magnesium Doesn’t Burn so Quickly like paper or matchstick or Paper But when it starts burning. Then you can see in the above video how it Becomes Burns. (Read more about the Burning of Magnesium in activity 1.1.)

How to represent Chemical Equations?

Chemical Equation: This is a shorter way to represent any chemical reaction. For Eg: When magnesium Burns in the presence of Air it Forms Magnesium oxide.

But, in Chemical equation: Mg+o2—> MgO (This is quite easy.)

Rules for writing the chemical reaction in Equation Form:

  1. you have studied in class 9th chapter 3. That how to write a chemical Reaction in forms of formulas and Equations.
  2. Check Equation is balanced or not. (The equation should be balanced.) **Unbalanced chemical reactions are called a skeletal chemical reaction.
  3. The physical state of the species should be Mentioned. Eg;- 2Mg(s) + o2(g)—>2MgO(s)

How to balance a Chemical Reaction.

First of all why to Balance a Chemical reaction.

You all have studied Earlier in class 9th about the law of Conservation of mass and Law of constant Proposition.

Law of Conversion of Mass:- According to this law mass can Neither be Created nor be Destroyed during a chemical reaction. ( By Antonie Lavisiver)

Law of Constant Proportion: In any particular chemical compound( Like H2O), all samples of that compound will be made up of the same elements in the same proportion/ratio (either you take the rainwater, sewage water or tap water). The ratio will always be equal to 2:1 of hydrogen and Oxygen Atom.

So, To Satisfy these Reactions we need to balance the chemical Equations.

How to balance the chemical reactions?

Although this is very easy to understand. But this is a little bit difficult to teach you through text, that how to balance a Chemical Reaction. That’s why to watch this video till the end.

A video for the chapter:

Balance these following Chemical Reaction: ============>(Add a quiz)

Page no. 6. question and answers.

Types of Chemical Reactions:

● Combination Reaction.
● Decomposition Reaction.
● Displacement Reaction.
● Double Displacement Reaction.
● Redox Reaction.

● Neutralization Reaction.
● Endothermic Reaction.
● Exothermic Reaction.
● Precipitation Reaction.

1.) Combination Reaction: This is a type of reaction when two or more thin two Elements/compounds combine together to form a single Compound.

NCERT Class 10th Science Ch-1 Notes Decomposition Chemical Reaction

2.) Decomposition Reaction: This is a type of reaction where single compound Decomposes in two or more than two compounds/Elements. This is the opposite of the Combination Reaction.

Types of decomposition Reaction:-

Electrolytic decomposition Reaction:- This is a type of reaction, In which we use Electricity to decompose the Compound. Example:- H2O (Decomposition of electricity.)

Photolytic Decomposition Reaction:- Sunlight is used for the decomposition of the Compound. Example:- AgCl walla example ka photo okay.

Thermal Decomposition Reaction:- Heat is used for the Decomposition of the Compound. Example:-

3) Displacement Reaction: This is a type of chemical reaction, where More reactive compound Displaces the less reactive compound from its salt, and form a new salt/Compound. Example:-

NCERT Class 10th Science Ch-1 Notes Decomposition Chemical Reaction
NCERT Class 10th Science Ch-1 Notes Decomposition Chemical Reaction

4.) Double Displacement Reaction

This is a type of Reaction in which, An exchange of ions between the reactants takes place to form new products.

Redox reaction:- It is a type of reaction in which the oxidation and Reduction Both takes place simultaneously.

Oxidation reaction: when any Element gain Oxygen or losses hydrogen is called Oxidation.

Reduction: It is a type of reaction in which, Elements gains hydrogen or loses oxygen is called Reduction.

5.) Neutralization Reaction.

This is a type of reaction in which, an acid and a base react quantitatively with each other to produce salt and water. Example:- NaOH (aq) + HCl (aq) –> NaCl (aq) + H2O (Liq)

Endothermic reaction: This is a type of reaction, in which During reaction Energy in the form of heat is absorbed from the Surroundings. Examples:-

  • Melting ice cubes.
  • Melting solid salts.
  • Evaporating liquid water.

Exothermic reaction:- This is a type of reaction in which energy is released in the Atmosphere in the form of heat. Examples of Exothermic Reactions: 1.) Combustion of fuels such as wood, coal and oil petroleum. 2). Respiration is also an example of an Exothermic Reaction.

Precipitation Reaction: It is a type of reaction in which an Insoluble salt is produced. For Example:- AgNO3(Aq) + KCl(aq) —–AgCl(white ppt.) + KNO3(aq)

Corrosion and Raincidity:-

Corrosion:- It is a natural process that converts metal into a more chemically-stable form such as oxide or hydroxide. It happens when any metal came in direct contact with the Oxygen and water for a long time then it Gradually Starts Degrading the material by Chemical reaction with their environment.

** Corrosion of Iron is Called Rusting. [4Fe(s)+3O2+xH2O(moisture)→2Fe2O3.xH2O] (This is the Formula of rust.)**

Methods for the Prevention of corrosion.

1). Apply paint.

2). Greasing.

3). Electroplating

Rancidity:- The oxidation of fat and oil-containing Food material is called as Rancidity. It gives false smell and worst taste to food, If you’ll eat the rancid food it can also cause problems like a stomachache.


(i) Use of air-tight containers.
(ii) Packaging with nitrogen or Aluminium Foil Packaging
(iii) Refrigeration.
(iv) **Addition of antioxidants like BHT(butylated hydroxytoluene) or BHA (Butylated hydroxyanisole)

If you have any doubt realated to this chapter then please let us know in the comment section. We will definety answer your Questions.

Now I hope these short and detailed notes are helpful to you. If this was helpful to you then just don’t forget to share with all other friends.

Now if you have completed with NCERT Class 10th Science Ch-1 Notes. This is the time to do the NCERT Question/Answers of this chapter all well as the Extra Questions after that Exemplar Problems, Practice problems and Then Finally Quiz.

Now I am not forcing you to complete it right now I know because you are just hopefully tired. I am just recommending to you what to do next. If you have completed with NCERT Class 10th Science Ch-1 Notes.

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