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NCERT Solutions for Class 10 Science Chapter 1 – Chemical Reactions And Equations
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Chapter 1 – Chemical Reactions And Equations
Intext Questions with Solutions of Class 10 Science Chapter 1 – Chemical Reactions and Equations
1.
Ans: Magnesium ribbon must be cleansed prior to combustion in air, as magnesium metal reacts with atmospheric oxygen to generate a stable coating of magnesium oxide (MgO). As a result, it is essential to clean the ribbon to remove the coating of magnesium oxide (MgO) in order to prevent any further interactions with oxygen.
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Ans: (i) Substance ‘X’ is calcium oxide also known as quicklime that is used in white washing. Its chemical formula is CaO.
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Ans: Water is electrolyzed in Activity 1.7 to produce H2 gas at one electrode and O2 gas at the other electrode.
Accordingly, when two molecules of water are electrolyzed, two molecules of hydrogen gas and one molecule of oxygen gas are produced; in other words, twice as much hydrogen gas would be collected as oxygen gas.
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Ans: Because iron is more reactive than copper, it displaces copper out of the copper sulfate solution when an iron nail is dipped in it. As a result, the copper sulphate solution’s color changes. The reaction is
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Ans: In a double displacement reaction, two ions move from one place to another in the reactants to make new compounds in the products. When sodium hydroxide and hydrochloric acid mix to make sodium chloride and water, this is called a double displacement process.
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Ans: (i) As oxygen is reduced and absorbed, sodium is oxidized.
(ii) When hydrogen obtains oxygen, it oxidizes, reducing substances like copper.
Exercise Questions with Solutions of Class 10 Science Chapter 1 – Chemical Reactions and Equations
1.
Ans: Incorrect option is (i) (a) and (b)
Explanation: (a) Because Oxygen is being removed and (b) Because the removed oxygen from Lead is added to the elemental Carbon.
2.
Ans: The answer is(d) Displacement reaction.
This happens when the oxygen in ferrous oxide moves to aluminium metal, making aluminium oxide. Aluminium, which is more reactive than iron, pushes iron out of its oxide in this reaction. This is called a displacement reaction, and it happens when a more reactive element takes the place of a less reactive one.
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Ans: (a) Hydrogen gas and iron chloride are produced.
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Ans: A balanced equation is one in which the number of distinct atoms on both the reactant and product sides is equal. Balancing chemical equations is essential for the reaction to adhere to the Law of Conservation of Mass. Therefore, a balanced chemical equation maintains that the total mass of the reactants is equivalent to the total mass of the products.
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Ans: Exothermic reactions: Exothermic reactions are those that result in the evolution of heat. Writing “+ Heat” on the products side of an equation indicates an exothermic reaction (Examples: Explosions, respiration, nuclear fission and fusion).
eg: C (s) + O2 (g) → CO2 (g) + Heat
Endothermic reactions: Endothermic reactions are those in which heat is absorbed. “Heat” is typically written on the product side of a chemical equation to indicate an endothermic reaction (For example, Photosynthesis, melting of ice, evaporation).
eg: N2 (g) + O2 (g) → 2NO(g) – Heat
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Ans: Exothermic reactions are the ones that give off heat. These reactions create energy because the reactants have more energy than the products. The process via which our body’s glucose and oxygen in our cells combine to give us energy is called respiration. Respiration is an exothermic reaction since the glucose is broken down during digestion, which also gives us energy when combined with oxygen. The following is the reaction that takes place:
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Ans: One compound decomposes into two or more simpler compounds in a decomposition reaction.
In contrast, two or more chemicals merely join to generate a new substance in a combination reaction.
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Ans: A displacement reaction occurs when a more reactive substance displaces a less reactive one from its salt solution, whereas a double displacement reaction occurs when two compounds exchange ions mutually.
In a displacement reaction, a single displacement occurs, while in a double displacement reaction, two displacements occur between the molecules, as the name implies.
Example:
Displacement reaction
Mg + 2HCl → MgCl2 + H2
Double displacement reaction
2KBr + BaI2 → 2KI + BaBr2
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Ans: A precipitation reaction is the kind of reaction in which the reactants exchange ions to generate an insoluble material known as a precipitate.
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Ans: Copper metal (Cu) is the gleaming brown element. Copper oxide is created when the metal reacts with atmospheric oxygen while heated in air. Thus, copper oxide is the black-colored substance.
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Ans: Because it is a reactive metal, iron can react with air and moisture. Long-term exposure to air or moisture can cause iron objects to corrode and develop rust. Therefore, paint is put to iron objects to stop them from rusting and to create a barrier against moisture and air exposure.
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Ans: Items that contain oils or fat are perishable and can go bad when they come into contact with oxygen. The reason for this is because oil and fats are easily oxidized due to their reactive nature. These objects are flushed with nitrogen gas to stop oxidation. Since nitrogen is an inert gas, it has a difficult time reacting with fats or oils. Food products that contain oils and fats are therefore stored in nitrogen gas-filled packets, which extends their shelf life and prolongs their shelf life.
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Ans: (a) The process of corrosion occurs when ambient oxygen oxidizes a refined metal to produce oxides or other more stable compounds. The corrosion process causes the metal to progressively deteriorate. An excellent illustration of corrosion is the rusting of iron, which turns the metal into iron oxide. Every year, millions of dollars are spent to keep bridges and other landmarks from rusting.
(b) The state that results in a disagreeable taste and odour due to the aerial oxidation of the fat and oil in the food. Because the low temperature in the refrigerator does not encourage the oxidation reaction, the rancidity is delayed.
Related Study Resources of Chapter 1 – Chemical Reactions And Equations
Students can use the links below to get extra study materials for Class 10 Science Chapter 1: Chemical Reactions And Equations.
| Sl No. | Related Links |
|---|---|
| 1 | Class 10 Science Chapter 1 Chemical Reactions And Equations – Important Questions |
| 2 | Class 10 Science Chapter 1 NCERT Textbook |
Download Chemical Reactions And Equations NCERT Solutions PDF
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Class 10 Science Chapter 1 Overview
The basis of chemistry is knowing how compounds interact, change, and make new things. Chapter 1, “Chemical Reactions and Equations,” is where students learn about this interesting idea. Our NCERT Solutions for Chemical Reactions and Equations will help you learn how to form balanced equations and make it easier to figure out what kind of reaction is happening. These solutions make things easier to understand so you can quickly relate them to the chemical changes that are happening in the real world
Also, one of the hardest things for pupils to do is balance chemical equations. We teach you methodical ways to balance instead of just remembering answers by breaking things down into steps. These NCERT solutions help you move from simple to more difficult equations, making even the most difficult redox or displacement reactions easier to deal with. Because of this, you have the courage to try both board test questions and applications for competitive jobs.
Our content has been meticulously based on the most recent NCERT syllabus for 2025. Unneeded repetition has been taken out, and more useful instances of chemical changes have been included. It explains things like oxidation, reduction, and real-life instances of corrosion and rancidity in a way that is easier to understand. Our NCERT Solutions for Chemical Reactions and Equations show you these changes and help you stay up to date with the most recent exam requirements.
Lastly, these answers are set up so that you may not only answer questions but also comprehend why each reaction happens. You may learn more and revise faster with clear explanations, examples that make sense, and answers that help you practice. Our solutions are a trusted study partner whether you’re getting ready for board examinations or merely want to strengthen your chemical skills.
FAQs – Class 10 Science Chapter 1
It seems hard to balance because it takes practice. Our NCERT solutions show you how to do things in a way that is more organized and easier.
A chemical reaction shows how the process works, while a chemical equation uses symbols to show it. Our answers make both of them plain to you.
By practicing with our solutions, you learn patterns like combination, decomposition, displacement, and redox. This makes it much easier to recognize them.
These are things that students typically get wrong. We use daily examples like rusting and breathing to describe them, which makes them easier to remember.
Content is structured, clear, and brief, so you don’t need explanations—everything is simplified.