Hello students! Welcome to this blog post, where we bring you a collection of CBSE Class 10 Chemistry MCQ questions from previous year papers. These questions have been carefully extracted to help you understand the exam pattern and boost your preparation. Whether you're looking to revise important concepts or practice for your upcoming exams, this post has got you covered. Stay tuned for valuable insights and tips to excel in your Science exam! Let's get started!
1. Select from the following a decomposition reaction in which source of energy for decomposition is light:
Answer: (c) 2AgBr → 2Ag + Br₂
2. Oxides of aluminium and zinc are:
Answer: (c) amphoteric
3. The compound having maximum number of water of crystallisation in its crystalline form in one molecule is:
Answer: (d) Na₂CO₃
4. The name and formula of third member of homologous series of alkyne is:
Answer: (d) Butyne C₄H₆
5. The reaction given above is a redox reaction because in this case:
Answer: (d) MnOâ‚‚ is reduced and HCl is oxidised
6. When 2 mL of sodium hydroxide solution is added to few pieces of granulated zinc in a test tube and then warmed, the reaction that occurs can be written in the form of a balanced chemical equation as:
Answer: (b) 2NaOH + Zn → Na₂ZnO₂ + H₂
7. A metal and a non-metal that exists in liquid state at the room temperature are respectively:
Answer: (c) Mercury and Bromine
8. Consider the following statements about homologous series of carbon compounds:
The correct statements are:
Answer: (A) (a) and (b)
9. The number of shells required to write the electronic configuration of Potassium (At. No. 19):
Answer: (D) 4
10. Select from the following a process in which a combination reaction is involved:
Answer: (B) Burning of coal
11. The oxide which can react with HCl as well as KOH to give corresponding salt and water is:
Answer: (B) Al₂O₃
12. Which of the following is an alloy of copper and tin?
Answer: (D) Bronze
13. Tooth decay begins at the pH of:
Answer: (B) 5.8
14. Solid Calcium oxide reacts vigorously with water to form Calcium hydroxide accompanied by the liberation of heat. From the information given above it may be concluded that this reaction:
Answer: (D) is exothermic and pH of the solution formed is more than 7.
15. A chemical compound used in glass, soap, and paper industries is:
Answer: (A) Washing Soda
16. Which one of the following reactions is different from the remaining three?
Answer: (B) CaO + H₂O → Ca(OH)₂
17. Identify the product 'X' obtained in the following chemical reaction:
CaCO₃ → X + CO₂
Answer: (A) Quick lime
18. Select a pair of natural indicators from the following:
Answer: (B) Turmeric and Litmus
19. Select saponification reaction from the following:
Answer: (C) CH₃COOC₂H₅ + NaOH → CH₃COONa + C₂H₅OH
20. Consider the following chemical equation:
a Al₂O₃ + b HCl → c AlCl₃ + d H₂O
In order to balance this chemical equation, the values of a, b, c, and d must be:
Answer: (A) 1, 6, 2, and 3
21. A chemical reaction in which exchange of ions occurs between the reactants is known as:
Answer: (C) Double Displacement Reaction
22. An aqueous solution of a salt turns blue litmus to red. The salt could be the one obtained by the reaction of:
Answer: (D) HCl and NHâ‚„OH
23. Four solutions, namely glucose, alcohol, hydrochloric acid, and sulphuric acid filled in four separate beakers are connected one by one in an electric circuit with a bulb. The solutions in which the bulb will glow when current is passed are:
Answer: (D) Hydrochloric acid and sulphuric acid
24. The metals which are found in both free state as well as combined state are:
Answer: (C) Copper and silver
25. The number of single and double bonds present in a molecule of benzene (C₆H₆) respectively, are:
Answer: (B) 9 and 3
26. Which of the following is not a thermal decomposition reaction?
Answer: (C) 2AgCl → 2Ag + Cl₂
27. An aqueous solution of sodium chloride is prepared in distilled water. The pH of this solution is:
Answer: (C) 7
28. A metal 'X' is used in thermit process. When 'X' is heated with oxygen, it gives an oxide 'Y', which is amphoteric in nature. 'X' and 'Y' respectively are:
Answer: (B) Al, Al₂O₃
29. The salt present in tooth enamel is:
Answer: (A) Calcium phosphate
30. Which of the following is a redox reaction, but not a combination reaction?
Answer: (D) Fe₂O₃ + 3CO → 2Fe + 3CO₂