Chemical Reactions and Equations Class 10 Science MCQs

Here are some multiple-choice questions (MCQs) for CBSE Chapter 1  Class 10 Science Chemical Reactions and Equations. These MCQs are designed to help students become familiar with the question types and their difficulty levels according to the updated CBSE Syllabus. With the recent changes in the exam pattern, MCQs have become an important part of the Class 10 Science Board exam. To assist students in understanding these question types, we have compiled MCQs specifically for Chapter 1 to make fundamentals strong. Additionally, answers to these MCQs are also available for students to reference. These MCQs are available in PDF format for download, enabling students to access them at any time during their studies. Students can also use the CBSE Class 10 Sample Papers books for more practice.

Important – CBSE Class 10 Science MCQ

CBSE Class 10 Chemical Reactions and Equations MCQs

Q.1. Among the following, the endothermic reaction is
(a) combination of carbon and oxygen to form carbon monoxide
(b) combination of nitrogen and oxygen to form nitrogen monoxide
(c) combination of glucose and oxygen to form carbon dioxide and water
(d) combination of zinc and hydrochloric acid to form zinc chloride and hydrogen.

Answer

(b)

Q.2. Formation of carbon disulphide from carbon and sulphur takes place by
(a) absorption of heat
(b) evolution of heat
(c) no change in heat content
(d) none of the above.

Answer

(a)
C + 2S → CS2 It is an endothermic reaction, resulting in absorption of heat.

 

Q.3. Identify X, Y, and the type of reaction occurring.

 

 

 

 

 

 

(a) H2, O2, Decomposition
(b) O2, H2, Displacement
(c) H2, O2, Displacement
(d) O2, H2, Decomposition

Answer

(d)

The given diagram shows electrolysis of water which is a type of decomposition reaction. When electric current is passed through acidified water, it decomposes to give hydrogen and oxygen gases. 2H2O(l)Electricity → 2H2(g)(2 volumes) O2(g)(1 volumes) electricity Since in the above reaction, 2 volumes of H2 gas and 1 volume of O2 gas are produced hence, Y is H2 gas and X is O2 gas

 

Also Check – CBSE Sample Papers Class 10 for 2024 Board Exams

Q.4. Copper displaces which of the following metal from its salt solution
(a) ZnSO4 (b) FeSO4
(c) AgNO3 (d) NiSO4

Answer

(c)
Cu + 2AgNO3 → Cu(NO3)2 + 2Ag Copper can displace silver from its salt solution since copper is more reactive than silver.

 

Q.5. The chemical reaction involved in the corrosion of metal is that of
(a) oxidation as well as displacement
(b) reduction as well as combination
(c) oxidation as well as combination
(d) reduction as well as displacement.

Answer

(c)

 

Q.6. Which of the following is not an example of decomposition reaction?
(a) CaCO_3(s) → CaO_(s) + CO_2(g)
(b) Ca(OH)_2(s) → CaO_(s) + H₂O_(l)
(c) CuSO₄.5H₂O_(s) → CuSO_4(s) + 5H₂O_(l)
(d) 2KClO_3(s) → 2KCl_(s) + 3O_2(g)

Answer

(c)
In all other reactions except (c) the compound decomposes to give simpler products while in (c) only the water of crystallisation is separated from the compound.

 

Q.7. In the balanced equation, Cu + xHNO3 → Cu(NO3)2 + yNO2 + 2H2O the values of x and y are
(a) 3 and 5 (b) 8 and 6
(c) 4 and 2 (d) 7 and 1

Answer

(c)
Cu + 4HNO₃ → Cu(NO₃) ₂ + 2NO₂ + 2H₂O

 

Q.8. Which of the following statements about the following reactions is correct?
ZnO + CO → Zn + CO2
(a) ZnO is being oxidized.
(b) CO is being reduced.
(c) CO2 is being oxidized.
(d) ZnO is being reduced.

Answer

(d)
ZnO is reduced to Zn and CO is oxidised to CO₂

 

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Q.9. In the reaction between lead sulphide and hydrogen peroxide which substance is reduced?
PbS + 4H₂O₂ → PbSO₄ + 4H₂O
(a) Lead sulphide (b) Hydrogen peroxide
(c) Lead sulphate (d) Water

Answer

(b)
H₂O₂ is reduced to water by removal of oxygen

 

Q.10. Which of the following reactions is used in white washing walls?
(a) 2Ca + O₂ → 2CaO
(b) Ca(OH)₂ Heat → CaO + H₂O
(c) Ca(OH)₂ + CO₂ → CaCO₃ + H₂O
(d) CaO + H₂O → Ca(OH)₂

Answer

(c)
Lime is mixed with water to give slaked lime and applied on the walls. When slaked lime or Ca(OH)₂ absorbs CO₂ from the atmosphere it forms a shining white substance lime stone which gives shining white colour to the walls. Ca(OH)₂ + CO₂ → CaCO₃ ↓ + H₂O

CBSE Class 10 Science Chemical Reactions and Equations MCQs – PDF Download

Answers – 

Topics covered in “Chemical Reactions and Equations”

1. Chemical equations
2. Writing a Chemical Equation
3. Balanced Chemical Equations
4. Types of chemical reactions
5. Combination Reaction
6. Decomposition Reaction
7. Displacement Reaction
8. Double Displacement Reaction
9. Oxidation and Reduction
10. Corrosion
11. Rancidity

Summary for NCERT Class 10 Science Chapter 1 – “Chemical Reactions and Equations”

• A complete chemical equation represents the reactants, products and their physical states symbolically.
• A chemical equation is balanced so that the numbers of atoms of each type involved in a chemical reaction are the same on the reactant and product sides of the equation. Equations must always be balanced.
• In a combination reaction two or more substances combine to form a new single substance.
• Decomposition reactions are opposite to combination reactions. In a decomposition reaction, a single substance decomposes to give two or more substances.
• Reactions in which heat is given out along with the products are called exothermic reactions.
• Reactions in which energy is absorbed are known as endothermic reactions.
• When an element displaces another element from its compound, a displacement reaction occurs.
• Two different atoms or groups of atoms (ions) are exchanged in double displacement reactions.
• Precipitation reactions produce insoluble salts.
• Reactions also involve the gain or loss of oxygen or hydrogen by substances. Oxidation is the gain of oxygen or loss of hydrogen. Reduction is the loss of oxygen or gain of hydrogen.

 

We hope the MCQs for CBSE Class 10 Science Chapter 1 on Chemical Reactions and Equations are helpful for your board exam preparation.

Best Reference Books for Class 10 Science

• NCERT Textbook + Exemplar Problems-Solutions
• Foundation Course Physics, Chemistry and Biology
• NCERT at your Fingertips Science
• 100 Percent Science
• CBSE 10 Years Chapterwise Topicwise Solved Papers AKA CBSE Champion
• CBSE Chapterwise Question Bank
• CBSE Score More 15 Sample Question Papers

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