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 13 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 13 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. What is the effect of pH on the reduction potential of Cr in dichromate? A) The reduction potential of Cr in dichromate is unaffected by pH. B) The reduction potential of Cr in dichromate is higher in alkaline conditions. C) The reduction potential of Cr in dichromate increases in acidic conditions and decreases in alkaline conditions. D) The reduction potential of Cr in dichromate decreases in acidic conditions. Show Answer Correct Answer: C) The reduction potential of Cr in dichromate increases in acidic conditions and decreases in alkaline conditions. 2. Which oxidation state shown by alkali metals? A) +2. B) +1. C) -1. D) -2. Show Answer Correct Answer: B) +1. 3. As an element is oxidized, its oxidation number A) Decreases as electrons are gained. B) Decreases as electrons are lost. C) Increases as electrons are lost. D) Increases as electrons are gained. Show Answer Correct Answer: B) Decreases as electrons are lost. 4. Determine the oxidation number of each element in SF$_{6}$. A) F:-6, S:+1. B) S:+1, F:-1. C) S:+6, F:-6. D) S:+6, F:-1. Show Answer Correct Answer: D) S:+6, F:-1. 5. What is the oxidation state of nitrogen in the Haber process? A) -1. B) -3. C) 0. D) -2. Show Answer Correct Answer: B) -3. 6. What is the oxidation number of Cr in Cr$_{2}$O$_{7}$$^{2-}$? A) +14. B) -6. C) +6. D) -14. Show Answer Correct Answer: C) +6. 7. What does the term 'electropositivity' refer to? A) The tendency of an atom to form ionic bonds. B) The tendency of an atom to lose electrons. C) The ability of an atom to form covalent bonds. D) The ability of an atom to gain electrons. Show Answer Correct Answer: B) The tendency of an atom to lose electrons. 8. What is the oxidation state of the hydrogen in OH$^{-}$ A) +1. B) -2. C) +2. D) -1. Show Answer Correct Answer: A) +1. 9. What is the furthest oxidative state for a primary alcohol? A) Alcohol. B) Carboxylic acid. C) Ketone. D) Aldehyde. E) Carbon dioxide. Show Answer Correct Answer: B) Carboxylic acid. 10. What is the oxidation state of nitrogen in NH4+? A) -3. B) 0. C) +3. D) +1. Show Answer Correct Answer: A) -3. 11. What is the purpose of balancing redox equations in half-reactions? A) None of the above. B) To simplify the equation. C) To double the number of electrons. D) To ensure conservation of mass. Show Answer Correct Answer: D) To ensure conservation of mass. 12. What happens at the positive electrode? A) Positive metal ions are attracted. B) Negative non-metal ions are attracted. C) Positive non-metal ions are attracted. D) Negative metal ions are attracted. Show Answer Correct Answer: B) Negative non-metal ions are attracted. 13. How does an Mg atom turn into an Mg ion? A) It loses an electron. B) It gains two electrons. C) It gain an electron. D) It loses two electrons. Show Answer Correct Answer: D) It loses two electrons. 14. In a redox reaction, the substance that donates electrons is called the: A) Oxidizing agent. B) Catalyst. C) Reducing agent. D) Inhibitor. Show Answer Correct Answer: C) Reducing agent. 15. In the reaction $\text{2Fe}_2\text{O}_3 + 3\text{C} \rightarrow 4\text{Fe} + 3\text{CO}_2$ A) Oxygen (O). B) Carbon (C). C) Carbon dioxide ( $\text{CO}_2$. D) Iron (Fe). Show Answer Correct Answer: B) Carbon (C). 16. Why are the terms oxidation and reduction considered misleading? A) They are only used in biology. B) They do not always accurately describe electron transfer. C) They are outdated and no longer used. D) They always involve oxygen. Show Answer Correct Answer: B) They do not always accurately describe electron transfer. 17. Given the equation:2 Al + 3 Cu$^{2+}$ $\rightarrow$ 2 Al$^{3+}$ + 3 CuThe reduction half-reaction is A) Cu$^{2+}$ + 2e$^{-}$ $\rightarrow$ Cu. B) Cu$^{2+}$ $\rightarrow$ Cu + 2e$^{-}$. C) Al + 3e$^{-}$ $\rightarrow$ Al$^{3+}$. D) Al $\rightarrow$ Al$^{3+}$ + 3e$^{-}$. Show Answer Correct Answer: A) Cu$^{2+}$ + 2e$^{-}$ $\rightarrow$ Cu. 18. Which element is being oxidized in the following chemical reaction?2KMnO$_{4 }$+ 5KNO$_{2}$ + 3H$_{2}$SO$_{4 }$$\rightarrow$$_{ }$2MnSO$_{4}$ + 3H$_{2}$O + 5KNO$_{3}$ + K$_{2}$SO$_{4}$ A) Mn. B) O. C) N. D) S. Show Answer Correct Answer: C) N. 19. Oxidation half-reaction involves ..... of electron/s. A) Gain. B) Loss. C) All the above. D) None of the above. Show Answer Correct Answer: B) Loss. 20. Which of the following statements is true about an electrochemical cell? A) Oxidation occurs at the cathode. B) Electrons flow from the anode to the cathode. C) Electrons flow from the cathode to the anode. D) Reduction occurs at the anode. Show Answer Correct Answer: B) Electrons flow from the anode to the cathode. 21. Which change is an oxidation? A) Fe$_{2}$O$_{3}$ to FeO. B) FeO to Fe$_{2}$O$_{3}$. C) H$_{2}$O$_{2}$ to H$_{2}$O. D) H$_{2}$O to H$_{2}$. Show Answer Correct Answer: B) FeO to Fe$_{2}$O$_{3}$. 22. A reaction where oxidation and reduction happens is a ..... A) Competition reaction. B) Redox reaction. C) Displacement reaction. D) Replacement reaction. Show Answer Correct Answer: B) Redox reaction. 23. In redox reaction, substance that undergo reduction is A) Reducing agent. B) Oxidising agent. C) All the above. D) None of the above. Show Answer Correct Answer: B) Oxidising agent. 24. Why is carbon included in the reactivity series? A) It conducts electricity. B) It is more reactive than copper. C) It acts as a metal. D) It is used to extract metals. Show Answer Correct Answer: D) It is used to extract metals. 25. The balanced half reaction in which the dichromate ion is reduced to chromium metal is a ..... A) 3 electron. B) 6 electron. C) 12 electron. D) Four electron. E) 2 electron. Show Answer Correct Answer: C) 12 electron. 26. What is the oxidation number of phosphorus in phosphate ion, PO$_{4}$$^{3-}$? A) 0. B) +1. C) +5. D) -5. Show Answer Correct Answer: C) +5. 27. Conjugate redox pairs are written A) Oxidant / reductant. B) Reductant / oxidant. C) All the above. D) None of the above. Show Answer Correct Answer: A) Oxidant / reductant. 28. A metal ion M$^{3+}$ loses 3 electrons. Its oxidation number will be? A) +3. B) +6. C) +7. D) +3. Show Answer Correct Answer: B) +6. 29. What is the oxidation number of sulfur in H2SO4? A) 0. B) +6. C) +2. D) +4. Show Answer Correct Answer: B) +6. 30. In the reaction Sn$^{+2}$ + 2 Fe$^{+3}$ $\rightarrow$ Sn$^{+4}$ + 2 Fe$^{+2}$, the reducing agent is ..... A) Sn$^{+2}$. B) Fe$^{+2}$. C) Fe$^{+3}$. D) Sn$^{+4}$. Show Answer Correct Answer: A) Sn$^{+2}$. 31. Which change in oxidation number indicates oxidation? A) -1 to +2. B) +2 to-3. C) +3 to +2. D) -1 to-2. Show Answer Correct Answer: A) -1 to +2. 32. What is the oxidation number of chromium in CrCl$_{3}$? A) -1. B) -3. C) -2. D) +3. Show Answer Correct Answer: D) +3. 33. What is the oxidation number of C in SrCO$_{3}$? A) -4. B) +4. C) +2. D) -6. Show Answer Correct Answer: B) +4. 34. What determines the maximum cell voltage under standard conditions in a galvanic cell? A) The difference in concentration of the electrolyte solutions. B) The physical size of the electrodes. C) The temperature of the electrolyte solutions. D) The difference in standard electrode potentials of the two half-cells. Show Answer Correct Answer: D) The difference in standard electrode potentials of the two half-cells. 35. In the galvanic cell using the redox reaction below, the reduction half-reaction is ..... Zn(s) + Cu$^{2+ }$(aq) $\rightarrow$ Zn$^{2+ }$(aq) + Cu (s) A) Zn + 2 e$^{-}$$\rightarrow$ Zn$^{2+}$. B) Zn $\rightarrow$ Zn$^{2+ }$+ 2 e$^{-}$. C) Cu$^{2+}$+ 2 e$^{-}$$\rightarrow$ Cu. D) Cu$^{2+ }$$\rightarrow$ Cu + 2 e$^{-}$. Show Answer Correct Answer: C) Cu$^{2+}$+ 2 e$^{-}$$\rightarrow$ Cu. 36. The loss of hydrogen or electrons is known as A) Hydrogenation. B) Reduction. C) Dehydration. D) Oxidation. Show Answer Correct Answer: D) Oxidation. 37. The negatively charged ions (anions) are attracted to the ..... A) Anode. B) Cathode. C) All the above. D) None of the above. Show Answer Correct Answer: A) Anode. 38. Which one of the following gives three correct definitions of reduction? A) Addition of oxygen, removal of hydrogen, addition of electrons. B) Addition of oxygen, addition of hydrogen, addition of electrons. C) Removal of oxygen, addition of hydrogen, removal of electrons. D) Removal of oxygen, addition of hydrogen, addition of electrons. Show Answer Correct Answer: D) Removal of oxygen, addition of hydrogen, addition of electrons. 39. What is the oxidation state of chlorine in NaClO3? A) -1. B) +1. C) +5. D) +3. Show Answer Correct Answer: C) +5. 40. In the following reaction:Zn (s) + Pb(NO$_{3}$)$_{2}$ (aq) $\rightarrow$ Pb (s) + Zn(NO$_{3}$)$_{2}$ (aq)What undergoes reduction? A) Zinc (Zn). B) Lead (Pb). C) Lead ion (Pb$^{2+}$). D) Zinc ion (Zn$^{2+}$). Show Answer Correct Answer: C) Lead ion (Pb$^{2+}$). 41. In the reaction @@ext{2Na} + ext{Cl} ..... 2 ightarrow 2ext{NaCl}@@, which element is oxidized? A) Sodium (Na). B) Chlorine (Cl). C) Sodium chloride (NaCl). D) None. Show Answer Correct Answer: A) Sodium (Na). 42. What substance is oxidized in the following reaction? Fe$^{+}$$^{2}$ + MnO$_{4 }$$\rightarrow$ Fe$^{+}$$^{3}$ + Mn$^{+}$$^{2}$ $^{}$ A) Mn$^{+3}$. B) Mn$^{+2}$. C) Fe$^{+2}$. D) MnO$_{4}$. Show Answer Correct Answer: C) Fe$^{+2}$. 43. What is an anion? A) A negatively charged ion that has gained one or more electrons. B) A neutral ion with no charge. C) A positively charged ion that has lost one or more electrons. D) An ion that can either gain or lose electrons. Show Answer Correct Answer: A) A negatively charged ion that has gained one or more electrons. 44. What is the result of the reaction between silver diamine and an organic aldehyde? A) Production of elemental nitrogen. B) Creation of hydrogen peroxide. C) Release of oxygen gas. D) Formation of carboxylic acid, ammonia, and water. Show Answer Correct Answer: D) Formation of carboxylic acid, ammonia, and water. 45. What does it mean for an element to be reduced? A) The element is in ion form in solution. B) There are fewer atoms in the product than in the reactant. C) The element has reacted with oxygen. D) The element has gained one or more electrons. Show Answer Correct Answer: D) The element has gained one or more electrons. 46. Process that is defined as the gain of electrons. A) Reduction. B) Redox. C) Reducing agent. D) Oxidation. Show Answer Correct Answer: A) Reduction. 47. Iodate ion, IO$_{3}$$^{-}$, is an oxidising agent. The half-equation for the reaction isIO$_{3}$$^{-}$(aq) + 6H$^{+}$(aq) +?e$^{-}$ $\rightarrow$ I$^{+}$(aq) + 3H$_{2}$O(l)The value of? in this equation is A) 3. B) 5. C) 4. D) 6. Show Answer Correct Answer: C) 4. 48. What is happening to the chemical in bold?Aluminium + chromium oxide $\rightarrow$ aluminium oxide + chromium A) Oxidation. B) Reduction. C) All the above. D) None of the above. Show Answer Correct Answer: B) Reduction. 49. Which substance is an oxidising agent? A) Magnesium powder. B) Bromine water. C) Iron(II) chloride solution. D) Potassium iodide solution. Show Answer Correct Answer: B) Bromine water. 50. What is happening to the chemical in bold?Nickel + oxygen $\rightarrow$ nickel oxide A) Oxidation. B) Reduction. C) All the above. D) None of the above. Show Answer Correct Answer: A) Oxidation. 51. Which of the following is an example of a synthesis reaction: A) 2 Na + Cl$_{2}$ $\rightarrow$ 2 NaCl. B) 2 H$_{2}$O $\rightarrow$ 2 H$_{2}$ + O$_{2 }$. C) CH$_{4}$ + 2 O$_{2}$ $\rightarrow$ 2 H$_{2}$O + CO$_{2}$. D) 2 HCl + Zn $\rightarrow$ ZnCl$_{2 }$+ H$_{2}$. Show Answer Correct Answer: A) 2 Na + Cl$_{2}$ $\rightarrow$ 2 NaCl. 52. What type of reaction is this:C$_{2}$H$_{2 }$becomes C$_{2}$H$_{6}$ A) Neither. B) Combustion. C) Reduction. D) Oxidation. Show Answer Correct Answer: C) Reduction. 53. What is happening to the chemical in bold?Aluminium oxide $\rightarrow$ aluminium + oxygen A) Oxidation. B) Reduction. C) All the above. D) None of the above. Show Answer Correct Answer: B) Reduction. 54. Choose all the processes that are redox reactions. A) Melting of ice. B) Fractional distillation of liquid mixtures. C) Rusting of iron, forming rust, which is hydrated iron(III) oxide. D) Sublimation of iodine crystals. Show Answer Correct Answer: C) Rusting of iron, forming rust, which is hydrated iron(III) oxide. 55. Al (s) + FeSO$_{4}$ (aq) $\rightarrow$ Al$_{2}$(SO$_{4}$)$_{3}$ (aq) + Fe (s)Which statements are true about this reaction?I. Al (s) reduces Fe$^{2+}$ (aq)II. Al (s) is the oxidizing agent.III. FeSO$_{4}$ is the reducing agent. A) I and II only. B) I and III only. C) II and III only. D) I, II and III. Show Answer Correct Answer: B) I and III only. 56. What is the oxidation number of Cl in HClO4? A) +3. B) +5. C) +7. D) +1. Show Answer Correct Answer: C) +7. 57. Which of the following elements is the strongest reducing agent? A) Bromine. B) Zinc. C) Florine. D) Iron. Show Answer Correct Answer: C) Florine. 58. Which of following is correct about given reaction:-Cl2 + H2S $\rightarrow$ S + 2HCl A) H2S undergo reduction. B) Cl2 undergo oxidation. C) H2S is oxidising agent. D) Cl2 is oxidising agent in the reaction. Show Answer Correct Answer: D) Cl2 is oxidising agent in the reaction. 59. Which one of the following metals reacts most vigorously with cold water? A) Zinc. B) Magnesium. C) Copper. D) Sodium. Show Answer Correct Answer: D) Sodium. 60. What is the oxidation number of oxygen in H$_{2}$O? A) +1. B) +2. C) -2. D) 0. Show Answer Correct Answer: C) -2. ← 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