This quiz works best with JavaScript enabled. Home > Cbse > Class 11 > Science > Chemistry Part Ii > Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions – Quiz 12 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 12 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. What is happening to the chemical in bold?Iron oxide + hydrogen $\rightarrow$ iron + water A) Oxidation. B) Reduction. C) All the above. D) None of the above. Show Answer Correct Answer: B) Reduction. 2. Choose the RIGHT statement A) If the oxidation number of an element changes, it is a redox reaction. B) In a redox reaction, there must be addition or removal of oxygen. C) The nature of redox reaction is the increase of element's oxidation number. D) An oxidising agent is oxidised in a redox reaction. Show Answer Correct Answer: A) If the oxidation number of an element changes, it is a redox reaction. 3. What is the significance of the purple color of KMnO4 in redox reactions? A) The purple hue is due to the presence of potassium ions in the solution. B) The color change signifies the reduction of KMnO4 to Mn2+ ions. C) The purple color indicates the presence of MnO2 in the +4 oxidation state. D) The purple color of KMnO4 signifies the presence of MnO4-ions in the +7 oxidation state, serving as a visual indicator in redox reactions. Show Answer Correct Answer: D) The purple color of KMnO4 signifies the presence of MnO4-ions in the +7 oxidation state, serving as a visual indicator in redox reactions. 4. Which element was oxidized in the reaction below?Na + PbCl$_{2 }$$\rightarrow$ Pb + NaCl A) Pb. B) Cl. C) Na. D) No element was reduced. Show Answer Correct Answer: C) Na. 5. The oxidation number of a substance in a reaction change from 0 to-1. The substance is A) Reducing agent. B) Oxidising agent. C) All the above. D) None of the above. Show Answer Correct Answer: B) Oxidising agent. 6. How does the oxidation state of manganese change during a redox reaction? A) Manganese can only be oxidized, never reduced. B) The oxidation state of manganese can only decrease during a redox reaction. C) The oxidation state of manganese remains constant in all reactions. D) The oxidation state of manganese can increase or decrease depending on whether it is oxidized or reduced. Show Answer Correct Answer: D) The oxidation state of manganese can increase or decrease depending on whether it is oxidized or reduced. 7. An element in a compound turns into an element in a chemical reaction. The element ..... A) May have been oxidisied or reduced. B) Is neither oxidised nor reduced. C) Is definitely reduced. D) Is definitely oxidised. Show Answer Correct Answer: C) Is definitely reduced. 8. 2MnO$_{4}$$^{-}$ + 5C$_{2}$O$_{4}$$^{2-}$ + 8H$^{+ }$$\rightarrow$ 2Mn$^{2+}$ + 10CO$_{2}$ + 4H$_{2}$OWhich species has been reduced? A) Oxygen. B) Hydrogen. C) Manganate. D) Carbon. Show Answer Correct Answer: C) Manganate. 9. Which statement is true concerning an oxidation-reduction reaction? A) The reactant which loses electrons is the oxidizing agent. B) The reactant which gains electrons is the reducing agent. C) The reactant which is oxidized is the oxidizing agent. D) The reactant that is reduced is the oxidizing agent. Show Answer Correct Answer: D) The reactant that is reduced is the oxidizing agent. 10. In which substance does bromine have an oxidation number of +1? A) HBr. B) Br$_{2}$. C) HBrO. D) HBrO$_{2}$. Show Answer Correct Answer: C) HBrO. 11. What is the oxidation number of Ca in Ca$_{3}$N$_{2}$? A) -3. B) +3. C) -2. D) +2. Show Answer Correct Answer: D) +2. 12. Which is true of the activity series of metals? A) More reactive metal is a better reducing agent. B) Less reactive metal replaces the more reactive metal. C) More reactive metal will be reduced. D) The less reactive metal will be at the anode. Show Answer Correct Answer: A) More reactive metal is a better reducing agent. 13. In the reaction 4Fe + 3O2 $\rightarrow$ 2Fe2O3, which element is being reduced? A) Iron. B) Oxygen. C) Iron(III) oxide. D) None of the above. Show Answer Correct Answer: B) Oxygen. 14. Which element is getting oxidised in reaction?2NaH $\rightarrow$ 2Na + H A) Na. B) H. C) Both. D) None. Show Answer Correct Answer: B) H. 15. What is a half-reaction of this equation, 2Na + Cl$_{2}$ $\rightarrow$ 2NaCl? A) Cl + e$^{-}$ $\rightarrow$ Cl$^{-}$. B) Na$^\circ$ + Cl$^\circ$$\rightarrow$ Na$^{+1}$Cl$^{-1}$. C) Cl-e$^{-}$ $\rightarrow$ Cl$^{-}$. D) Na $\rightarrow$ Na + e$^{-}$. Show Answer Correct Answer: A) Cl + e$^{-}$ $\rightarrow$ Cl$^{-}$. 16. What is the coefficient of the permanganate ion when the follow equation is balanced? MnO$_{4}$$^{-}$+ Br$^{-}$$\rightarrow$ Mn$^{2+ }$+ Br$_{2 }$(acidic solution) A) 5. B) 4. C) 3. D) 2. E) 1. Show Answer Correct Answer: B) 4. 17. Reactions in voltaic cells are A) Spontaneous, redox reactions. B) Spontaneous, non-redox reactions. C) Non-spontaneous, non-redox reactions. D) Non-spontaneous, redox reactions. Show Answer Correct Answer: A) Spontaneous, redox reactions. 18. What is oxidation state of Sulphur in H2SO4? A) +6. B) -6. C) -4. D) +4. Show Answer Correct Answer: A) +6. 19. What precipitate forms when you mix lead (II) nitrate with sodium chloride? A) Lead (II) chloride. B) Sodium nitrate. C) Chloride nitrate. D) Sodium lead. Show Answer Correct Answer: A) Lead (II) chloride. 20. Which method is the best to extract zinc from its ore? A) Heating with limestone. B) Heating with coal. C) Mining from earth crust. D) Electrolysis. Show Answer Correct Answer: B) Heating with coal. 21. The overall sum of oxidation numbers for a compound needs to be equal to? A) -1. B) -2. C) +2. D) +1. E) 0. Show Answer Correct Answer: E) 0. 22. Which of the following is a reduction reaction? A) Hydrogen sulphide loses hydrogen. B) Bromine molecule gains electron. C) Zinc atom loses electrons. D) Carbon gains oxygen. Show Answer Correct Answer: B) Bromine molecule gains electron. 23. What is happening to the chemical in bold?Carbon + zinc oxide $\rightarrow$ carbon dioxide + zinc A) Oxidation. B) Reduction. C) All the above. D) None of the above. Show Answer Correct Answer: B) Reduction. 24. In their compounds, all ..... metals have oxidation number of +1, and all ..... metals have an oxidation number of +2. A) Alkali, transition. B) Alkali, innertransition. C) Alkali, alkaline. D) Transition, innertransition. Show Answer Correct Answer: C) Alkali, alkaline. 25. In the reaction $Zn + Cu^{2+} \rightarrow Zn^{2+} + Cu$ A) $Zn^{2+}$. B) $Cu^{2+}$. C) $Cu$. D) $Zn$. Show Answer Correct Answer: D) $Zn$. 26. What is the oxidizing agent in the following reaction?Zn (s) + Cu$^{2+ }$(aq) $\rightarrow$ Zn$^{2+ }$(aq) + Cu (s) A) Cu (s). B) Zn (s). C) Cu$^{2+ }$(aq). D) Zn$^{2+ }$(aq). Show Answer Correct Answer: C) Cu$^{2+ }$(aq). 27. Oxidation is the loss of electron, meaning, there is an increase of oxidation number A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 28. In the reaction, Zn(s) + 2HCl(aq) $\rightarrow$ ZnCl$_{2}$(aq) + H$_{2}$(g) which one of the following statements is wrong? A) Zinc loses electrons. B) Chlorine gains electron. C) Zinc is oxidised. D) Hydrogen chloride is reduced. Show Answer Correct Answer: B) Chlorine gains electron. 29. Zn(s) + 2HCl(aq) $\rightarrow$ ZnCl$_{2}$(aq) + H$_{2}$(g)Hydrogen is reduced because A) HCl lost chlorine. B) It lost electrons when H$^{+}$ became H$_{2}$. C) Its oxidation state decreased from +1 to 0. D) Zinc is reduced. Show Answer Correct Answer: C) Its oxidation state decreased from +1 to 0. 30. Oxidized substance in a redox reaction is called as ..... A) Oxidizing agent. B) Reducing agent. C) Oxidation number. D) Spectator ion. Show Answer Correct Answer: B) Reducing agent. 31. Which of the following reactions will occur spontaneously as written? A) 3 Fe (s) + 2 Cr$^{3+ }$(aq) $\rightarrow$ 2 Cr (s) + 3 Fe$^{2+ }$(aq). B) Sn$^{4+ }$(aq) + Fe$^{3+ }$(aq) $\rightarrow$ Sn$^{2+ }$(aq) + Fe$^{2+}$ (aq). C) Sn$^{4+ }$(aq) + Fe$^{2+ }$(aq) $\rightarrow$ Sn$^{2+ }$(aq) + Fe (s). D) 3 Sn$^{4+ }$(aq) + 2 Cr (s) $\rightarrow$ 2 Cr$^{3+ }$(aq) + 3 Sn$^{2+}$ (aq). Show Answer Correct Answer: D) 3 Sn$^{4+ }$(aq) + 2 Cr (s) $\rightarrow$ 2 Cr$^{3+ }$(aq) + 3 Sn$^{2+}$ (aq). 32. What is the function of the anode in an electrochemical cell? A) The anode is where electrons are collected in an electrochemical cell. B) The anode generates electrical energy from chemical reactions. C) The anode is the site of oxidation in an electrochemical cell. D) The anode is the site of reduction in an electrochemical cell. Show Answer Correct Answer: C) The anode is the site of oxidation in an electrochemical cell. 33. A/an ..... agent is a substance that has the potential to cause another substance to be reduced. A) Reducing. B) Oxidizing. C) Biological. D) Chemical. Show Answer Correct Answer: A) Reducing. 34. Which of the following is a common oxidising agent:H2O2, NaCl, or CH4? A) H2O2. B) H2O. C) NaOH. D) C2H6. Show Answer Correct Answer: A) H2O2. 35. The following is what type of reaction:PbCl$_{2}$ + AgNO$_{3}$ $\rightarrow$ Pb(NO$_{3}$)$_{2}$ + AgCl A) Synthesis. B) Decomposition. C) Double Replacement. D) Single Replacement. Show Answer Correct Answer: C) Double Replacement. 36. During a redox reaction, A) The number of e-lost is always less than equals the number of e-gained. B) Cannot tell. C) The number of e-lost always equals the number of e-gained. D) The number of e-lost is always more than the number of e-gained. Show Answer Correct Answer: C) The number of e-lost always equals the number of e-gained. 37. In the following reaction:2CuO (s) + C (s) $\rightarrow$ 2Cu (s) + CO$_{2}$ (g)What undergoes oxidation? A) Carbon dioxide (CO$_{2}$). B) Carbon (C). C) Copper (Cu). D) Copper ions (Cu$^{2+}$). Show Answer Correct Answer: B) Carbon (C). 38. Oxidation occurs when a substance gain electrons A) TRUE. B) FALSE. C) All the above. D) None of the above. Show Answer Correct Answer: B) FALSE. 39. It is when an atom's oxidation state increases during a reaction. A) Oxidation. B) Reduction. C) Reduction-oxidation reaction. D) None of the given choices. Show Answer Correct Answer: A) Oxidation. 40. What is occurring in this reaction 2Mg$_{(s)}$ + O$_{2(g)}$ $\rightarrow$ 2MgO$_{(s)}$? A) Oxygen atom displaces the magnesium atoms. B) A solid magnesium ribbon is undergoing reduction while oxygen is undergoing oxidation. C) A solid magnesium ribbon is undergoing oxidation while oxygen is undergoing reduction. D) A transfer of electrons from oxygen to magnesium. Show Answer Correct Answer: C) A solid magnesium ribbon is undergoing oxidation while oxygen is undergoing reduction. 41. The sum of the oxidation numbers in SCN$^{-}$ is equivalent to A) +3. B) -1. C) +1. D) 0. Show Answer Correct Answer: B) -1. 42. If an atom lost electrons, it ..... A) Was reduced. B) Was oxidized. C) Was burned. D) It became negative. Show Answer Correct Answer: B) Was oxidized. 43. Is Zn$^{2+}$ an oxidizing agent or reducing agent? A) Oxidizing agent. B) Reducing agent. C) Neither. D) Both. Show Answer Correct Answer: A) Oxidizing agent. 44. A redox reaction is a chemical reaction where ..... A) Oxidation occurs. B) Reduction occurs. C) Oxidation and reduction occurs simultaneously. D) Oxidation occur followed by reduction. Show Answer Correct Answer: C) Oxidation and reduction occurs simultaneously. 45. Corrosion, a type of redox reaction, can cause cars and buildings to rust. Rusting happens when iron is oxidized by oxygen in the air. This process happens when ..... A) Oxygen acts as the reducing agent and gains electrons. B) Iron acts as the reducing agent and loses electrons. C) Oxygen acts as the oxidizing agent and loses electrons. D) Iron acts as the oxidizing agent and gains electrons. Show Answer Correct Answer: B) Iron acts as the reducing agent and loses electrons. 46. In the reaction $\text{2H}_2 + \text{O}_2 \rightarrow 2\text{H}_2\text{O}$ A) Hydrogen ( $\text{H}_2$. B) Oxygen ( $\text{O}_2$. C) Water ( $\text{H}_2\text{O}$. D) None. Show Answer Correct Answer: B) Oxygen ( $\text{O}_2$. 47. Which change indicates oxidation? A) Sn$^{4+}$ becomes Sn$^{2+}$. B) Cr$^{3+}$ becomes Cr$^{6+}$. C) Fe$^{3+}$ becomes Fe. D) None of the above. Show Answer Correct Answer: B) Cr$^{3+}$ becomes Cr$^{6+}$. 48. In the reaction 2H2 + O2 $\rightarrow$ 2H2O, what is the oxidation state of hydrogen in water? A) +1. B) 0. C) -1. D) +2. Show Answer Correct Answer: A) +1. 49. Which of the following would not increase the amount of a metal being electroplated? A) Increasing the solution concentration. B) Increasing the time of electrolysis. C) Increasing the charge of the ion. D) Increasing the current. Show Answer Correct Answer: C) Increasing the charge of the ion. 50. What is the reducing agent of this reaction?3Mg + N$_{2}$$\rightarrow$ Mg$_{3}$N$_{2}$ A) Mg$_{3}$N$_{2}$. B) MgN. C) Mg. D) N$_{2}$. Show Answer Correct Answer: C) Mg. 51. Which is false about redox reactions? A) Involve a transfer of electrons. B) Losing electrons is oxidation. C) The oxidizing agent increases its oxidation state. D) Include single replacement reactions. Show Answer Correct Answer: C) The oxidizing agent increases its oxidation state. 52. Identify the oxidizing and reducing agents in the reaction:2Mg + O2 $\rightarrow$ 2MgO. A) Reducing agent:O2, Oxidizing agent:MgO. B) Reducing agent:O2, Oxidizing agent:Mg. C) Reducing agent:Mg, Oxidizing agent:O2. D) Reducing agent:MgO, Oxidizing agent:O2. Show Answer Correct Answer: C) Reducing agent:Mg, Oxidizing agent:O2. 53. What type of redox reaction involves the transfer of electrons between two species? A) Decomposition reaction. B) Combustion reaction. C) Oxidation-reduction reaction. D) Synthesis reaction. Show Answer Correct Answer: C) Oxidation-reduction reaction. 54. For redox reactions, half equations show A) Electrons loss and gain for each element, and together they show the complete redox reaction. B) Show transfer of electrons without any change in oxidation states. C) Spectator ions and how they lose and gain electrons. D) Show the complete reaction without needing to consider oxidation or reduction. Show Answer Correct Answer: A) Electrons loss and gain for each element, and together they show the complete redox reaction. 55. The S atom is in group 16 in periodic table and its theoritical maximum oxidation state is ..... A) +4. B) +2. C) -2. D) +6. Show Answer Correct Answer: D) +6. 56. When a metal compound reacts with a more reactive metal, what sort of reaction occurs? A) Displacement. B) Neutralisation. C) Combustion. D) No Reaction. Show Answer Correct Answer: A) Displacement. 57. What is a cation? A) A negatively charged ion that has gained one or more electrons. B) A positively charged ion that has lost one or more electrons. C) A neutral atom with no charge. D) A type of molecule that contains both positive and negative charges. Show Answer Correct Answer: B) A positively charged ion that has lost one or more electrons. 58. These keep track of the movement of electrons. A) (+) and (-) signs. B) Oxidation numbers. C) Coefficients. D) Subscripts. Show Answer Correct Answer: B) Oxidation numbers. 59. Which statement is true of a reducing agent? A) It is oxidised as it loses electrons. B) It is oxidised as it gains electrons. C) It is reduced as it loses electrons. D) It is reduced as it gains electrons. Show Answer Correct Answer: A) It is oxidised as it loses electrons. 60. In displacement reactions, what happens when a more reactive metal is added to a solution of a less reactive metal compound? A) The more reactive metal displaces the less reactive metal. B) The less reactive metal displaces the more reactive metal. C) No reaction occurs. D) Both metals form a new compound. Show Answer Correct Answer: A) The more reactive metal displaces the less reactive metal. ← PreviousNext →Related QuizzesScience QuizzesClass 11 QuizzesClass 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 1Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 2Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 3Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 4Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 5Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 6Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 7Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 8 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books