Previous year questions of chemical reactions and equations are an essential resource for students preparing for their Class 10 Science exams. This chapter, which covers the fundamental concepts of chemical reactions, their types, and how to balance chemical equations, is crucial for building a strong foundation in chemistry.
Most omportant questions of Chemistry class 10 chapter 1 focus on key topics such as the characteristics of chemical reactions and the representation of these reactions through equations. By reviewing Class 10 Science Chapter 1 previous year questions, students can familiarize themselves with the exam format and the types of questions that frequently appear.
For those looking for a comprehensive study aid, the previous year questions of chemical reactions and equations class 10 PDF download offers a convenient way to access a collection of these important questions. Additionally, students can find important questions of chemical reactions and equations class 10 that have been curated to highlight the most relevant content for exam preparation.
Q1: Select from the following a decomposition reaction in which the source of energy for decomposition is light: (2024)
(a) 2FeSO4 → Fe2O3 + SO2 + SO3
(b) 2H2O → 2H2 + O2
(c) 2AgBr → 2Ag + Br2
(d) CaCO3 → CaO + CO2
Answer:
(c)
A decomposition reaction is when a compound breaks into simpler substances. Option (c) is correct as silver bromide (AgBr) decomposes into silver (Ag) and bromine (Br2) using light energy. The other options do not involve light as a source of energy.
Q2: When 2 mL of sodium hydroxide solution is added to granulated zinc in a test tube and warmed, the balanced chemical equation is: (2024)
(a) NaOH + Zn → NaZnO2 + H2O
(b) 2NaOH + Zn → Na2ZnO2 + H2
(c) 2NaOH + Zn → NaZnO2 + H2
(d) 2NaOH + Zn → Na2ZnO2 + H2O
Answer:
(b)
The reaction between sodium hydroxide (NaOH) and zinc (Zn) produces sodium zincate (Na2ZnO2) and hydrogen gas. The balanced equation is 2NaOH + Zn → Na2ZnO2 + H2.
Q3: Select the process involving a combination reaction: (2024)
(a) Black and White photography
(b) Burning of coal
(c) Burning of methane
(d) Digestion of food
Answer:
(b)
Burning of coal involves carbon (C) reacting with oxygen (O2) to form carbon dioxide (CO2):
C (s) + O2 (g) → CO2 (g). This is a combination reaction as two substances combine to form a single product.
Q4: Identify the cases where new products form: (2024)
(A) CaSO4 + Al →
(B) CuSO4 + Ca →
(C) FeSO4 + Cu →
(D) ZnSO4 + Mg →
(a) (A) and (B)
(b) (B) and (C)
(c) (C) and (D)
(d) (B) and (D)
Answer:
(d)
New products form when a more reactive metal displaces a less reactive metal. In (B) and (D), calcium and magnesium displace copper and zinc, forming new compounds.
Q5: Identify the correct statement about the following reaction: (2024)
2H2S + SO2 → 2H2O + S
(a) H2S is an oxidizing agent, and SO2 is a reducing agent.
(b) H2S is reduced to sulfur.
(c) SO2 is an oxidizing agent, and H2S is a reducing agent.
(d) SO2 is oxidized to sulfur.
Answer:
(c)
In this reaction, H2S loses hydrogen to form sulfur (acts as a reducing agent), and SO2 gains hydrogen to form water (acts as an oxidizing agent).
Q6: Balance the following chemical equation: (2024)
Al2O3 + HCl → AlCl3 + H2O
(a) 1, 6, 2, 3
(b) 1, 6, 3, 2
(c) 2, 6, 2, 3
(d) 2, 6, 3, 2
Answer:
(a)
The balanced equation is:
Al2O3 + 6HCl → 2AlCl3 + 3H2O.
Q7: Which reaction differs from the others? (2024)
(a) NaCl + AgNO3 → AgCl + NaNO3
(b) CaO + H2O → Ca(OH)2
(c) KNO3 + H2SO4 → KHSO4 + HNO3
(d) ZnCl2 + H2S → ZnS + 2HCl
Answer:
(b)
Explanation to be added based on the required differentiation.
Q8: Zn + 2CH3COOH → Zn(CH3COO)2 + H2 (2024)
(a) Decomposition reaction
(b) Displacement reaction
(c) Double displacement reaction
(d) Combination reaction
Answer:
(b)
This is a displacement reaction as zinc (Zn) replaces hydrogen in acetic acid, forming zinc acetate and hydrogen gas.
Q9: Balance the following chemical equation: (2024)
2Zn(NO3)2 → 2ZnO + 4NO2 + O2
(a) 4, 2, 2
(b) 4, 4, 2
(c) 2, 2, 4
(d) 2, 4, 2
Answer:
(c)
Balanced equation:
2Zn(NO3)2 → 2ZnO + 4NO2 + O2.
Q10: Identify the redox reaction that is not a combination reaction: (2024)
(a) C + O2 → CO2
(b) 2H2 + O2 → 2H2O
(c) 2Mg + O2 → 2MgO
(d) Fe2O3 + 3CO → 2Fe + 3CO2
Answer:
(d)
In this reaction, Fe2O3 is reduced to Fe, and CO is oxidized to CO2, making it a redox reaction but not a combination reaction.
Previous year questions of chemical reactions and equations help students familiarize themselves with the exam format and the types of questions that are frequently asked.
Students can easily download the previous year questions of chemical reactions and equations class 10 pdf from Infinity Learn:
Download PDF in a single click:
Practicing previous year questions of chemical reactions and equations helps students understand the exam format, identify important topics, and improve their problem-solving skills, ultimately enhancing their confidence for the exam.
You can download the Class 10 science chapter 1 previous year questions PDF from various educational websites like Selfstudys, EduRev, or Vedantu, which provide comprehensive collections along with solutions.
Yes, most resources that offer previous year questions of chemical reactions and equations include detailed solutions. This allows students to verify their answers and understand the reasoning behind each solution, aiding in better preparation.