This quiz works best with JavaScript enabled. Home > Class 10 > Class 10 Science Chapter 1 Chemical Reactions And Equations – Quiz 15 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 10 Science Chapter 1 Chemical Reactions And Equations Quiz 15 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. What happens in a chemical reaction? A) Bonds between atoms break and/or are formed. B) New atoms are created and/or removed. C) Protons move from one atom to another. D) Electrons change into protons. Show Answer Correct Answer: A) Bonds between atoms break and/or are formed. 2. How many Oxygen (O) atoms are in 2C$_{2}$HO$_{8}$C$_{l2}$ A) 2. B) 16. C) 8. D) 5. Show Answer Correct Answer: B) 16. 3. Which of the following may indicate that a chemical reaction has occured? A) Release of energy as light. B) A color change. C) Gas bubble formation. D) All of these. Show Answer Correct Answer: D) All of these. 4. While performing an activity in the lab, Meera exhaled air into a colourless solution taken in a test tube. Suddenly its colour turned to milky white. Which among the following is the colourless solution? A) Lime water. B) Soda water. C) Aqueous solution of NaOH. D) Aqueous solution of NaCl. Show Answer Correct Answer: A) Lime water. 5. Na2SO4(aq) + BaCl2(aq) $\rightarrow$ BaSO4(s) + 2NaCl(aq)The given reaction is an example of: A) Double displacement reaction. B) Combination reaction. C) Displacement reaction. D) Decomposition reaction. Show Answer Correct Answer: A) Double displacement reaction. 6. Which observation would most likely indicate that an endothermic reaction has occurred? A) A color change. B) The production of gas bubbles. C) An increase in temperature. D) A decrease in temperature. Show Answer Correct Answer: D) A decrease in temperature. 7. When two or more substances combine to form a new substance it is called ..... A) Combination reaction. B) Decomposition reaction. C) Displacement reaction. D) Redox reaction. Show Answer Correct Answer: A) Combination reaction. 8. In which of the following process a chemical reaction has taken place? A) Ice melts into water. B) A wet shirt got dried in sunlight. C) A brown layer is formed over iron rod kept in air. D) Sugar getting dissolved in water. Show Answer Correct Answer: C) A brown layer is formed over iron rod kept in air. 9. Which of the following are exothermic processes? (i) Reaction of water with quick lime (ii) Dilution of an acid(iii) Evaporation of water (iv) Sublimation of camphor (crystals) A) (i) and (ii). B) (ii) and (iii). C) (i) and (iv). D) (iii) and (iv). Show Answer Correct Answer: A) (i) and (ii). 10. An element X on exposure to moist air turns reddish-brown and a new compound Y is formed. The substance X and Y are A) X = Fe, Y = Fe2O3. B) X = Ag, Y = Ag2S. C) X = Cu, Y = Cu O. D) X = al, y = al2o3. Show Answer Correct Answer: A) X = Fe, Y = Fe2O3. 11. When balancing equations, the rule is that you can only add, change, and remove A) Coefficients. B) Mass. C) Subscripts. D) Elements. Show Answer Correct Answer: A) Coefficients. 12. Consider equation:Pb$^{+2 }$(aq) + 2OH$^{-}$(aq) ..... > Pb(OH)$_{2}$ (s)Precipitate of lead (II) hydroxide will be of? A) Colourless. B) Brown. C) Yellow. D) White. Show Answer Correct Answer: D) White. 13. Which of the following represents a combination reaction? A) Reaction of zinc metal with copper sulphate solution. B) Heating of lead nitrate. C) .Burning of magnesium in air. D) Reaction between silver nitrate and sodium chloride. Show Answer Correct Answer: C) .Burning of magnesium in air. 14. Which of the following behaviours is true about the solution obtained by mixing CaO with water? A) Amphoteric solution. B) Basic solution. C) Acidic solution. D) Neutral solution. Show Answer Correct Answer: B) Basic solution. 15. What is the colour of Solid Mg? A) White. B) Colourless. C) Gray. D) Silver gray. Show Answer Correct Answer: D) Silver gray. 16. PRECIPITATION REACTION IS ALSO KNOWN AS A) DOUBLE DISPLACEMENT REACTION. B) DISPLACEMENT REACTION. C) EXOTHERMIC REACTION. D) CATALYST REACTION. Show Answer Correct Answer: A) DOUBLE DISPLACEMENT REACTION. 17. Who said "Facts are not science ..... as the dctionary is not literature." A) Martin H. Fischer. B) Albert Einstein. C) Newton. D) None of the above. Show Answer Correct Answer: A) Martin H. Fischer. 18. Which of the following happens in a chemical reaction? A) New substances with new properties are formed. B) Rearrangement of atoms. C) Bonds between atoms of reactants break and form bonds with atoms of products. D) All of these. Show Answer Correct Answer: D) All of these. 19. In writing a chemical equation, inclusion of state symbols shall be done while? A) While balancing equation. B) After equation has been balanced. C) While writing equation. D) Whenever you want. Show Answer Correct Answer: B) After equation has been balanced. 20. What is observed when a solution of potassium iodide is added to silver nitrate solution? A) No reaction takes place. B) White precipitate of silver iodide is formed. C) Yellow precipitate of AgI is formed. D) AgI is soluble in water. Show Answer Correct Answer: C) Yellow precipitate of AgI is formed. 21. Electrolysis of water is a decomposition reaction. The molar ratio of hydrogen and oxygen gases liberated during electrolysis of water is: A) 1:1. B) 2:1. C) 1:2. D) 4:1. Show Answer Correct Answer: B) 2:1. 22. This slows down a chemical reaction. A) Catalyst. B) Inhibitor. C) All the above. D) None of the above. Show Answer Correct Answer: B) Inhibitor. 23. The law of conservation of matter states that: A) Matter is neither created nor destroyed. B) The mass of the products is always greater than the mass of the reactants. C) The mass of the products is always less than the mass of the reactants. D) Matter is always converted into an equal amount of energy. Show Answer Correct Answer: A) Matter is neither created nor destroyed. 24. How can you tell if a chemical reaction occurs? A) Change in state. B) Change in color. C) Change in temperature. D) All of these. Show Answer Correct Answer: D) All of these. 25. One of the following is an exothermic reaction. This is A) Electrolysis of water. B) Conversion of limestone into quicklime. C) Process of respiration. D) Process of photosynthesis. Show Answer Correct Answer: C) Process of respiration. ← PreviousNext →Related QuizzesClass 10 Science Chapter 1 Chemical Reactions And Equations Quiz 1Class 10 Science Chapter 1 Chemical Reactions And Equations Quiz 2Class 10 Science Chapter 1 Chemical Reactions And Equations Quiz 3Class 10 Science Chapter 1 Chemical Reactions And Equations Quiz 4Class 10 Science Chapter 1 Chemical Reactions And Equations Quiz 5Class 10 Science Chapter 1 Chemical Reactions And Equations Quiz 6Class 10 Science Chapter 1 Chemical Reactions And Equations Quiz 7Class 10 Science Chapter 1 Chemical Reactions And Equations Quiz 8Class 10 Science Chapter 1 Chemical Reactions And Equations Quiz 9Class 10 Science Chapter 1 Chemical Reactions And Equations Quiz 10 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books