chemical reaction and equation test paper-class 10th science

Here is a comprehensive test paper for Class 10 Science Chapter 1: Chemical Reactions and Equations, designed to assess in-depth knowledge, competency, and familiarity with previous exam trends, aligned with the latest CBSE 2024-25 syllabus.

Section A: In-Depth Knowledge Questions

1. Balancing Complex Chemical Equations:

1. • Balance the following chemical equation and identify the type of reaction:
     • C₇H₆O₃ + O₂ → CO₂ + H₂O

2. Mechanism of Redox Reactions:

1. • Explain the process of oxidation and reduction with suitable examples. Discuss how electron transfer occurs in redox reactions and its significance in real-life applications.

3. Thermodynamics of Chemical Reactions:

1. • Differentiate between exothermic and endothermic reactions with examples. Explain how energy changes are represented in chemical equations and their implications in industrial processes.

Section B: Competency-Based Questions

4. Application of Chemical Reactions:

1. • A metal ‘X’ reacts with a non-metal ‘Y’ to form a compound ‘Z’. The compound ‘Z’ conducts electricity in the molten state and is soluble in water. Identify ‘X’, ‘Y’, and ‘Z’. Write the chemical equation for the formation of ‘Z’ and explain the properties of the compound formed.

5. Predicting Products of Reactions:

1. • Predict the products when aqueous solutions of barium chloride and sodium sulfate are mixed. Write the balanced chemical equation for the reaction and mention the type of reaction.

6. Analyzing Reaction Conditions:

1. • Hydrogen gas is not evolved when a metal reacts with nitric acid. Explain why. Write the chemical equations to support your answer.

Section C: Previous Year Questions

7. Decomposition Reactions:

1. • Write balanced chemical equations for the following decomposition reactions:
     • Decomposition of lead nitrate on heating.
     • Electrolysis of water.

8. Displacement Reactions:

1. • What happens when iron nails are placed in a solution of copper sulfate? Write the balanced chemical equation for the reaction and mention the type of reaction.

9. Observations in Chemical Reactions:

1. • When a solution of potassium iodide is added to a solution of lead nitrate in a test tube, a reaction takes place.
     • (a) What type of reaction is this?
     • (b) Write a balanced chemical equation to represent the above reaction.

Section D: NCERT Textbook Questions

10. Balancing Equations:

1. • Write the balanced chemical equation with state symbols for the following reactions:
     • Barium chloride reacts with sodium sulfate to produce barium sulfate and sodium chloride.
     • Sodium hydroxide reacts with hydrochloric acid to form sodium chloride and water.

11. Types of Reactions:

1. • Classify the following reactions as combination, decomposition, displacement, or double displacement reactions:
     • CaO + H₂O → Ca(OH)₂
     • 2KBr + BaI₂ → 2KI + BaBr₂
     • ZnCO₃ → ZnO + CO₂
     • H₂ + Cl₂ → 2HCl

Section E: Sample Paper Questions

12. Identifying Reaction Types:

1. • Identify the type of chemical reaction and write a balanced chemical equation for the following:
     • Magnesium ribbon is burnt in an atmosphere of nitrogen gas.

13. Real-Life Applications of Reactions:

1. • Why do we apply paint on iron articles? Explain the chemical process involved and write the relevant chemical equation.

14. Observing Chemical Changes:

1. • What happens when dilute hydrochloric acid is added to iron filings? Write the chemical equation for the reaction that takes place.

Section F: Case-Based Questions

15. Case Study on Corrosion:

1. • A school conducted an experiment where iron nails were exposed to different environments:
     • Sample A: Iron nails kept in dry air.
     • Sample B: Iron nails immersed in distilled water.
     • Sample C: Iron nails immersed in saltwater.
     • Sample D: Iron nails coated with zinc and kept in moist air.
   • After a week, observations were made regarding the rust formation on each sample.
     • (a) Which sample(s) showed the most rust, and why?
     • (b) Explain the chemical process of rusting with the help of a balanced chemical equation.
     • (c) Discuss the methods to prevent rusting and their underlying chemical principles.

16. Case Study on Decomposition Reactions:

1. • During a laboratory demonstration, a teacher heated a blue crystalline solid in a test tube. A gas was evolved, and a black residue was left behind.
     • (a) Identify the blue crystalline solid and the black residue formed.
     • (b) Write the balanced chemical equation for the decomposition reaction that took place.
     • (c) What type of chemical reaction is demonstrated in this experiment?
     • (d) Discuss the practical applications of such decomposition reactions in daily life or industry.

This test paper is designed to evaluate students’ understanding of chemical reactions and equations comprehensively, ensuring alignment with the latest CBSE syllabus and examination patterns.