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 4 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 4 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. What is the half-reaction method used for in balancing redox reactions? A) To identify the type of redox reaction. B) To calculate the overall energy change in a reaction. C) To balance redox reactions by separating oxidation and reduction processes. D) To determine the physical states of reactants and products. Show Answer Correct Answer: C) To balance redox reactions by separating oxidation and reduction processes. 2. Combustion reaction is an example of a redox reaction A) TRUE. B) FALSE. C) All the above. D) None of the above. Show Answer Correct Answer: A) TRUE. 3. In a galvanic cell, where does the oxidation reaction take place? A) Cathode. B) Anode. C) Salt bridge. D) Circuit. Show Answer Correct Answer: B) Anode. 4. What is the most likely oxidation state of aluminum (Al)? A) -2. B) +3. C) -3. D) +2. Show Answer Correct Answer: B) +3. 5. Which of the following is a characteristic of a redox reaction? A) Release of light. B) Transfer of electrons between species. C) Absorption of heat. D) Formation of a precipitate. Show Answer Correct Answer: B) Transfer of electrons between species. 6. What is the oxidation number of each atom in sodium chlorate NaClO$_{3}$? A) Na = +1; Cl = +3; O =-1. B) Na = +1; Cl = +7; O =-4. C) Na = +1; Cl = +5; O =-2. D) Na = +1; Cl = +7; O =-2. E) Na =-1; Cl = +5; O =-2. Show Answer Correct Answer: C) Na = +1; Cl = +5; O =-2. 7. Which of the following is a characteristic of oxidation? A) Reduction of electronegative elements. B) Gain of electrons. C) Loss of hydrogen. D) Addition of hydrogen. Show Answer Correct Answer: C) Loss of hydrogen. 8. Oxidizing agents are substances that oxidizes another substance ..... A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 9. If the oxidation number of an element reduces in a redox reaction, then this corresponds to the process of ..... A) Reduction. B) Oxidation. C) All the above. D) None of the above. Show Answer Correct Answer: A) Reduction. 10. Define reduction in terms of electron transfer. A) Reduction is the process in which an atom, ion, or molecule combines with oxygen. B) Reduction is the process in which an atom, ion, or molecule undergoes a change in temperature. C) Reduction is the process in which an atom, ion, or molecule gains electrons. D) Reduction is the process in which an atom, ion, or molecule loses electrons. Show Answer Correct Answer: C) Reduction is the process in which an atom, ion, or molecule gains electrons. 11. What is a redox reaction? A) A reaction where both reactants get reduced. B) A reaction where both reactants get oxidized. C) A reaction that involves a transfer of electrons between reactants. D) A reaction that involves the combustion of at least one reactant. Show Answer Correct Answer: C) A reaction that involves a transfer of electrons between reactants. 12. What is a common rule for assigning oxidation states to oxygen? A) +2. B) +1. C) -2. D) Zero. Show Answer Correct Answer: C) -2. 13. Defined as the gain of electrons A) Oxidation. B) Redox. C) Reduction. D) OIL RIG. Show Answer Correct Answer: C) Reduction. 14. This is the half reaction for:Sn(s) $\rightarrow$ Sn$^{4+}$(aq) + 4e$^{-}$ A) Neutralization. B) Reduction. C) Redox. D) Oxidation. Show Answer Correct Answer: D) Oxidation. 15. Which of the following is an example of a redox reaction involving a metal and a non-metal? A) $\text{H}_2 + \text{Cl}_2 \rightarrow 2\text{HCl}$. B) $\text{Mg} + \text{O}_2 \rightarrow \text{MgO}$. C) $\text{N}_2 + 3\text{H}_2 \rightarrow 2\text{NH}_3$. D) $\text{C} + \text{O}_2 \rightarrow \text{CO}_2$. Show Answer Correct Answer: B) $\text{Mg} + \text{O}_2 \rightarrow \text{MgO}$. 16. If an atom is reduced in a redox reaction, what must happen to another atom in the system? A) It must be oxidised. B) It must be reduced. C) Nothing needs to happen to another atom in the system. D) It must be neutralised. Show Answer Correct Answer: A) It must be oxidised. 17. In the following reaction, which species is the oxidizing agent and which gets reduced?2H$^{+}$$_{(aq)}$ + Mn$_{(s) }$$\rightarrow$ Mn$^{2+}$$_{(aq)}$ + H$_{2(g)}$ A) H$^{+}$ is the oxidizing agent and Mn gets reduced. B) H$^{+}$ is the oxidizing agent and H$^{+ }$gets reduced. C) Mn is the oxidizing agent and H$^{+ }$gets reduced. D) Mn is the oxidizing agent and Mn gets reduced. E) Mn is the oxidizing agent and Mn$^{2+}$ gets reduced. Show Answer Correct Answer: B) H$^{+}$ is the oxidizing agent and H$^{+ }$gets reduced. 18. Why does the chlorine gas are able to displace the bromide ion from its salt solution? A) Because the chlorine atoms transfer electrons from itself to the bromide atoms. B) Because chlorine atoms are more electropositive than the bromide atoms. C) Because chlorine atoms are more electronegative than the bromide ions. D) Because bromide atoms are more electronegative than the chloride ions. Show Answer Correct Answer: C) Because chlorine atoms are more electronegative than the bromide ions. 19. The chemical equation for the reaction between sodium hydride and water is $NaH+H_2O\longrightarrow NaOH+H_2$ A) An oxidising agent. B) A reducing agent. C) Both an oxidising agent and a reducing agent. D) Neither an oxidisding agent nor a reducing agent. Show Answer Correct Answer: A) An oxidising agent. 20. What is the oxidation state of manganese in KMnO4? A) +2. B) +7. C) +4. D) +6. Show Answer Correct Answer: B) +7. 21. What happens to magnesium when it reacts with a dilute acid? A) It gains electrons and is reduced. B) It loses electrons and is oxidized. C) It gains protons and is oxidized. D) It loses protons and is reduced. Show Answer Correct Answer: B) It loses electrons and is oxidized. 22. How do you convert a redox reaction into a balanced ionic equation? A) A balanced ionic equation is obtained by combining the balanced oxidation and reduction half-reactions, ensuring mass and charge are conserved. B) Use coefficients that do not conserve mass or charge. C) Only write the oxidation half-reaction and ignore the reduction half-reaction. D) Combine the oxidation and reduction reactions without balancing them. Show Answer Correct Answer: A) A balanced ionic equation is obtained by combining the balanced oxidation and reduction half-reactions, ensuring mass and charge are conserved. 23. Consider the following reaction.NO$_{3}$$^{-}$ (aq) + Cu (s) $\rightarrow$ NO (g) + Cu$^{2+}$ (aq)Which statement is correct? A) Cu (s) is the reducing agent because it gains electrons. B) Cu (s) is the oxidizing agent because it gains electrons. C) Cu (s) is the oxidizing agent because it loses electrons. D) Cu (s) is the reducing agent because it loses electrons. Show Answer Correct Answer: D) Cu (s) is the reducing agent because it loses electrons. 24. What is the oxidation number of each atom in H$_{3}$PO$_{4}$? A) H = 0; P = +3; O =-2. B) H =-1; P = +5; O =-2. C) H = +1; P = +1; O =-1. D) H = +1; P = +7; O =-2. E) H = +1; P = +5; O =-2. Show Answer Correct Answer: E) H = +1; P = +5; O =-2. 25. Combustion and single-replacement reactions are ..... redox reactions. A) Always. B) Never. C) Sometimes. D) Mostly. Show Answer Correct Answer: A) Always. 26. How do you determine the endpoint in a titration using KMnO4? A) The endpoint is indicated by a persistent faint pink color in the solution. B) The endpoint is marked by a sudden color change to dark purple. C) The endpoint is determined by the temperature of the solution. D) The endpoint is indicated when the solution becomes completely clear. Show Answer Correct Answer: A) The endpoint is indicated by a persistent faint pink color in the solution. 27. In the redox reaction AgNO$_{3}$ + Na $\rightarrow$ NaNO$_{3}$ + Ag, which element has been reduced? A) Silver (Ag). B) Oxygen (O). C) Nitrogen (N). D) Sodium (Na). Show Answer Correct Answer: A) Silver (Ag). 28. Which of the following statements is true about net ionic equations? A) They include all ions present in the reaction. B) They only include the ions that participate in the reaction. C) They include only the spectator ions. D) They are the same as molecular equations. Show Answer Correct Answer: B) They only include the ions that participate in the reaction. 29. The species that gain electron is ..... and usually the ..... agent A) Reduced;oxidizing. B) Oxidized;oxidizing. C) Oxidized; reducing. D) Reduced;reducing. Show Answer Correct Answer: A) Reduced;oxidizing. 30. ..... synthesis and decomposition reactions involve the transfer of electrons. A) All. B) Most. C) No. D) Some. Show Answer Correct Answer: B) Most. 31. The reaction H$_{2}$SO$_{4}$ + 2NaOH $\rightarrow$ Na$_{2}$SO$_{4}$ + 2H$_{2}$O A) Is a redox reaction. B) Is not a redox reaction. C) All the above. D) None of the above. Show Answer Correct Answer: B) Is not a redox reaction. 32. Balance the following redox equations for reactions that occur in neutral solution:Fe$^{3+}$ + I$^{-}$ $\rightarrow$ Fe$^{2+ }$+ I$_{2. }$: A) Fe$^{3+}$ + 2I$^{-}$ $\rightarrow$ Fe$^{2+}$ + 2I$_{2}$. B) Fe$^{3+}$ + I$^{-}$ $\rightarrow$ Fe$^{2+}$ + I$_{2}$. C) 2Fe$^{3+}$ + I$^{-}$ $\rightarrow$ 2Fe$^{2+}$ + I$_{2}$. D) 2Fe$^{3+}$ + 2I$^{-}$ $\rightarrow$ 2Fe$^{2+}$ + I$_{2}$. Show Answer Correct Answer: D) 2Fe$^{3+}$ + 2I$^{-}$ $\rightarrow$ 2Fe$^{2+}$ + I$_{2}$. 33. How many electrons are transferred in the reaction of MnO4-with I-? A) 5 electrons are transferred in the reaction. B) 10 electrons are transferred in the reaction. C) 8 electrons are transferred in the reaction. D) 12 electrons are transferred in the reaction. Show Answer Correct Answer: B) 10 electrons are transferred in the reaction. 34. What is the oxidation state of the hydroxide ion in the reaction with silver diamine? A) -1. B) 0. C) +1. D) +2. Show Answer Correct Answer: A) -1. 35. 2Na + 2H$_{2}$O $\rightarrow$ 2NaOH + H$_{2}$Which statement is correct? A) Hydrogen is oxidised from +1 to 0. Sodium is reduced from 0 to +1. B) Hydrogen is reduced from +2 to 0. Sodium is oxidised from 0 to +2. C) Hydrogen is reduced from +1 to 0. Sodium is oxidised from 0 to +1. D) Hydrogen is oxidised from +2 to 0. Sodium is reduced from 0 to +2. Show Answer Correct Answer: C) Hydrogen is reduced from +1 to 0. Sodium is oxidised from 0 to +1. 36. What is the name of this equation:Fe$^{2+}$ $_{(aq)}$ + 2e$^{-}$ $\rightarrow$ Fe$_{(s)}$ A) A full redox equation. B) A net chemical equation. C) A half redox equation. D) An overall chemical equation. Show Answer Correct Answer: C) A half redox equation. 37. What is the oxidation number of chromium in $K_2Cr_2O_7$ A) +3. B) +2. C) +7. D) +6. Show Answer Correct Answer: D) +6. 38. Describe the role of electrons in redox reactions. A) Electrons are only involved in ionic reactions. B) Electrons are produced during redox reactions but not transferred. C) Electrons are transferred between reactants, causing oxidation and reduction in redox reactions. D) Electrons do not play a significant role in chemical reactions. Show Answer Correct Answer: C) Electrons are transferred between reactants, causing oxidation and reduction in redox reactions. 39. During the formation of an ionic compound metal atoms act as ..... A) Oxidizing agents. B) Oxidants. C) Reducing agents. D) Spectator ions. Show Answer Correct Answer: C) Reducing agents. 40. Which of these metals tends to resist losing electrons to corrosion? A) Aluminium. B) Platinum. C) Iron. D) Zinc. Show Answer Correct Answer: B) Platinum. 41. What is used to indicate the oxidation number? A) Numbers. B) Integers. C) Roman numerals. D) None of the above. Show Answer Correct Answer: C) Roman numerals. 42. What is the oxidation state of free elements? A) Zero. B) Two. C) Three. D) One. Show Answer Correct Answer: A) Zero. 43. Is Cl$_{2}$ an oxidizing agent or reducing agent? A) Oxidizing agent. B) Reducing agent. C) Neither. D) Both. Show Answer Correct Answer: A) Oxidizing agent. 44. Oxidation number of H in NaH: A) +2. B) 0. C) -1. D) +1. Show Answer Correct Answer: C) -1. 45. What is the oxidation number of Mg in MgCl$_{2 }$(Magnesium Chloride)? A) -2. B) -1. C) +2. D) +1. Show Answer Correct Answer: C) +2. 46. Which element is getting reduced?4Fe+ 3O$_{2}$$\rightarrow$2Fe$_{2}$O$_{3}$ A) O. B) Fe. C) Both. D) None. Show Answer Correct Answer: A) O. 47. Which particles DOES NOT have reducing power? A) Chloride ion. B) Chlorine water. C) Hydrogen ion. D) Hydrogen gas. Show Answer Correct Answer: C) Hydrogen ion. 48. ..... is the loss of electrons. A) Oxidation. B) Reduction. C) Redox. D) All chemical reactions. Show Answer Correct Answer: A) Oxidation. 49. Identify the type of redox reaction:Cl$_{2}$ (g) + 2 OH$^{-}$ (aq) $\rightarrow$ ClO$^{-}$ (aq) + Cl$^{-}$$_{ }$ (aq) + H$_{2}$O (l) A) Combination. B) Decomposition. C) Disproportionation. D) Displacement. Show Answer Correct Answer: C) Disproportionation. 50. What happens to the oxidation state of an element when it is oxidized? A) It decreases. B) It becomes negative. C) It increases. D) It remains the same. Show Answer Correct Answer: C) It increases. 51. What substance is oxidized in the following reaction?4Fe + 3O$_{2}$ $\rightarrow$ 2Fe$_{2}$O$_{3}$ A) Iron. B) Fluorine. C) Oxygen. D) None of the above. Show Answer Correct Answer: A) Iron. 52. What happens to the oxidation number of an element during reduction? A) The oxidation number fluctuates. B) The oxidation number decreases. C) The oxidation number remains the same. D) The oxidation number increases. Show Answer Correct Answer: B) The oxidation number decreases. 53. What is a voltmeter? A) The liquid part of the electrochemical cell. B) The metal part of the electrochemical cell. C) The part that measures the voltage in an electrochemical cell. D) None of the above. Show Answer Correct Answer: C) The part that measures the voltage in an electrochemical cell. 54. What is reduction in redox reactions? A) Losing electrons. B) Sharing electrons. C) Gaining electrons. D) None of the above. Show Answer Correct Answer: C) Gaining electrons. 55. Identify the reducing agent in the following reaction.H$_{2}$S + 2 FeCl$_{3}$ $\rightarrow$ 2 FeCl$_{2}$ + 2 HCl + S A) S. B) FeCl$_{2}$. C) H$_{2}$S. D) FeCl$_{3}$. Show Answer Correct Answer: C) H$_{2}$S. 56. Oxidation-reduction reactions occur because of the competition between particles for ..... A) Absolutely-not-rons. B) Neutrons. C) Electrons. D) Protons. Show Answer Correct Answer: C) Electrons. 57. Reduction reaction occurs when a substance gain electrons A) TRUE. B) FALSE. C) All the above. D) None of the above. Show Answer Correct Answer: A) TRUE. 58. In the reaction @@ext{Zn} + ext{CuSO} ..... 4 ightarrow ext{ZnSO} ..... 4 + ext{Cu}@@, which element is oxidized? A) O. B) S. C) Zn. D) Cu. Show Answer Correct Answer: C) Zn. 59. In the Haber process, what happens to nitrogen's oxidation state? A) It increases, indicating oxidation. B) It decreases, indicating reduction. C) It alternates between increasing and decreasing. D) It remains the same. Show Answer Correct Answer: B) It decreases, indicating reduction. 60. What is oxidation number of H in H$_{2}$O? A) -1. B) -2. C) +1. D) 0. Show Answer Correct Answer: C) +1. ← 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 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 8Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 9 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books