Q1. What type of reaction occurs when calcium oxide and water combine to form a single product, calcium hydroxide?
Q2. Quick lime is:
Q3. Quick lime is calcium oxide, with the chemical formula:
Q4. In the reaction CaO(s) + H₂O(l) → Ca(OH)₂(aq), what is observed regarding temperature?
Q5. What is the product formed when calcium hydroxide reacts with carbon dioxide in the air during whitewashing?
Q6. What gives a shiny finish to walls after whitewashing?
Q7. What is the chemical formula of marble?
Q8. Which of the following is a combination reaction?
Q9. In simple language, what defines a combination reaction?
Q10. What is the product in the combination reaction: 2H₂(g) + O₂(g) → ?
Q11. Reactions in which heat is released along with the formation of products are called what?
Q12. The reaction between quicklime and water to form slaked lime is an example of what kind of reaction?
Q13. Which of the following is an exothermic reaction?
Q14. What process in our body is described as an exothermic process?
Q15. During respiration, what does glucose combine with in our cells to provide energy?
Q16. What are rice, potatoes, and bread broken down into during digestion?
Q17. What is the special name for the reaction where glucose provides energy by combining with oxygen?
Q18. Which of the following is also an example of an exothermic reaction?
Q19. In the balancing steps for Fe + H₂O → Fe₃O₄ + H₂, what was done first to balance oxygen atoms?
Q20. When balancing an equation, what must we remember NOT to alter?
Q21. In the partly balanced equation Fe + 4H₂O → Fe₃O₄ + H₂, which element was balanced next?
Q22. To equalise hydrogen atoms in the partly balanced equation, what coefficient was placed before H₂?
Q23. After balancing hydrogen, which element was left to be balanced in the equation 3Fe + 4H₂O → Fe₃O₄ + 4H₂?
Q24. What coefficient was placed before Fe to balance the iron atoms?
Q25. What is the final balanced equation for the reaction between iron and steam?
Q26. What is the method of balancing chemical equations described in the text called?
Q27. In the hit-and-trial method, what do we use to balance the equation?
Q28. What is the correct order of steps taken to balance Fe + H₂O → Fe₃O₄ + H₂?
Q29. After putting the coefficient 4 for H₂O, how many oxygen atoms are on the left side?
Q30. After putting the coefficient 4 for H₂, how many hydrogen atoms are on the right side?
Q31. In the final check of the balanced equation, what must be equal on both sides?
Q32. In the respiration equation, what are the products?
Q33. What is the primary purpose of respiration at the cellular level?
Q34. What type of reaction is the burning of coal (C + O₂ → CO₂)?
Q35. In the reaction for burning natural gas, what is the coefficient of O₂?
Q36. Which activity in the chapter involves a combination reaction that gives out heat?
Q37. What is the physical state of water (H₂O) in the respiration equation?
Q38. In the partly balanced equation (Step IV), Fe + 4H₂O → Fe₃O₄ + 4H₂, which element is still unbalanced?
Q39. What is the total number of hydrogen atoms on the left in the final balanced equation 3Fe + 4H₂O → Fe₃O₄ + 4H₂?
Q40. What is the key characteristic used to identify a reaction as a combination reaction?
Q41. What solution is used for whitewashing walls?
Q42. Why is the reaction between calcium oxide and water considered exothermic?
Q43. According to the text, what provides us with the energy to stay alive?
Q44. In the context of balancing, what does the term “smallest whole number coefficient” refer to?
Q45. What is the correct way to write “four water molecules” when balancing an equation?
Q46. After balancing, the final equation 3Fe + 4H₂O → Fe₃O₄ + 4H₂ has how many iron atoms on each side?
Q47. Which of these everyday processes is NOT mentioned as exothermic in the text?
Q48. What happens to the reaction mixture in an exothermic reaction?
Q49. In the balancing process, what was the state of the equation after Step V?
Q50. What is the main reason for balancing a chemical equation using the hit-and-trial method?