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 2 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 2 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. What does the mnemonic 'OILRIG' stand for? A) Oxidation is light, reduction is gravity. B) Oxygen is light, reduction is gain. C) Oxygen in layers, reduction in gas. D) Oxidation is loss of electrons, reduction is gain of electrons. Show Answer Correct Answer: D) Oxidation is loss of electrons, reduction is gain of electrons. 2. Explain the significance of the color change in KMnO4 titrations. A) The color change indicates the presence of excess KMnO4. B) The color change in KMnO4 titrations signifies the endpoint, indicating complete reaction of the analyte. C) The color change shows the temperature of the solution. D) The color change is irrelevant to the titration process. Show Answer Correct Answer: B) The color change in KMnO4 titrations signifies the endpoint, indicating complete reaction of the analyte. 3. What is the oxidation state of fluorine in compounds? A) +2. B) 0. C) -1. D) +1. Show Answer Correct Answer: C) -1. 4. An oxidizing agent is: A) Remains unchanged. B) Oxidized. C) Reduced. D) None of the above. Show Answer Correct Answer: C) Reduced. 5. What is happening to the chemical in bold?Magnesium + iron oxide $\rightarrow$ magnesium oxide + iron A) Oxidation. B) Reduction. C) All the above. D) None of the above. Show Answer Correct Answer: B) Reduction. 6. Indicate the oxidation number of phosphorus in each of the following compounds:HPO3 A) +3. B) -1. C) +1. D) -5. E) +5. Show Answer Correct Answer: E) +5. 7. A compound having +2 oxidation state of O is A) H2O2. B) OF2. C) O2F2. D) H2O. Show Answer Correct Answer: B) OF2. 8. What is the oxidation number of oxygen in OF$_{2 }$molecule? A) +2. B) -2. C) -1. D) +1. Show Answer Correct Answer: A) +2. 9. Which statement best describes a redox reaction? A) A single chemical reaction that involves the transfer of electrons. B) Two chemical reactions occurring simultaneously involving the transfer of electrons. C) An oxidation and reduction reaction. D) Rusting. Show Answer Correct Answer: B) Two chemical reactions occurring simultaneously involving the transfer of electrons. 10. In the redox reaction $MnO_4^-+ 8H^+ + 5e^-\rightarrow Mn^{2+} + 4H_2O$ $MnO_4^-$ A) Oxidation. B) Neutralization. C) Precipitation. D) Reduction. Show Answer Correct Answer: D) Reduction. 11. Which of the following elements does not show disproportionation tendency? A) Br. B) Cl. C) F. D) I. Show Answer Correct Answer: C) F. 12. In a redox reaction, there is a conservation of A) Mass, only. B) Charge, only. C) Both mass and charge. D) Neither mass nor charge. Show Answer Correct Answer: C) Both mass and charge. 13. Which of following is incorrect about oxidation state? A) Oxidation state of all elements in their elemental form is taken as zero. B) For ions composed of only one atom, theoxidation number is equal to the chargeon the. C) The algebraic sum of the oxidation numberof all the atoms in a compound must bezero. D) In metal hydrides oxidation state of Hydrogen is +1. Show Answer Correct Answer: D) In metal hydrides oxidation state of Hydrogen is +1. 14. Which half-reaction equation represents the reduction of a potassium ion? A) K$^{+}$ $\rightarrow$ K + e$^{-}$. B) K$^{+}$ + e$^{-}$ $\rightarrow$ K. C) K + e$^{-}$ $\rightarrow$ K$^{+}$. D) K $\rightarrow$ K$^{+}$ + e$^{-}$. Show Answer Correct Answer: B) K$^{+}$ + e$^{-}$ $\rightarrow$ K. 15. In which reaction does the oxidation state of iron remain unchanged? A) Fe + 2HCl $\rightarrow$ FeCl$_{2}$ + H$_{2}$. B) 2Fe + 3Cl$_{2}$ $\rightarrow$ 2FeCl$_{3}$. C) 2FeCl$_{2 }$ + Cl$_{2}$ $\rightarrow$ 2FeCl$_{3}$. D) Fe$_{2}$O$_{3}$ + 6HCl $\rightarrow$ 2FeCl$_{3}$ + 3H$_{2}$O. Show Answer Correct Answer: D) Fe$_{2}$O$_{3}$ + 6HCl $\rightarrow$ 2FeCl$_{3}$ + 3H$_{2}$O. 16. What is the oxidation state of sulfur in H2SO4? A) +4. B) +8. C) +2. D) +6. Show Answer Correct Answer: D) +6. 17. What is the primary focus of redox reactions? A) Combustion of fuels. B) Synthesis of metals. C) Formation of acids. D) Electron transfer processes. Show Answer Correct Answer: D) Electron transfer processes. 18. What is the sum of all oxidation numbers in a neutral compound? A) Equal to the charge of the compound. B) Always zero. C) Equal to the number of atoms. D) Always positive. Show Answer Correct Answer: B) Always zero. 19. Identify the oxidantH$_{2}$S + HNO$_{3}$ $\rightarrow$ NO + S + H$_{2}$O A) HNO$_{3}$. B) NO. C) S. D) H$_{2}$S. Show Answer Correct Answer: A) HNO$_{3}$. 20. What is the oxidation number of H in CH$_{4}$? A) +1. B) -4. C) -1. D) +4. Show Answer Correct Answer: A) +1. 21. Balance the following half-equations for reactions that occur in acidic solution:Zn + VO$^{2+}$ + H$^{+}$ $\rightarrow$ V$^{3+}$ + H$_{2}$O + Zn$^{2+}$ A) Zn + 2VO$^{2+}$ + 2H$^{+}$ $\rightarrow$ Zn$^{2+}$ + 2V$^{3+}$ + H$_{2}$O. B) 2Zn + 2VO$^{2+}$ + 4H$^{+}$ $\rightarrow$ Zn$^{2+}$ + 2V$^{3+}$ + 2H$_{2}$O. C) Zn + VO$^{2+}$ + 4H$^{+}$ $\rightarrow$ Zn$^{2+}$ + V$^{3+}$ + 2H$_{2}$O. D) Zn + 2VO$^{2+}$ + 4H$^{+}$ $\rightarrow$ Zn$^{2+}$ + 2V$^{3+}$ + 2H$_{2}$O. Show Answer Correct Answer: D) Zn + 2VO$^{2+}$ + 4H$^{+}$ $\rightarrow$ Zn$^{2+}$ + 2V$^{3+}$ + 2H$_{2}$O. 22. What is a spectator ion? A) An ion that undergoes oxidation. B) An that undergoes reduction. C) An ion not involved in the redox reaction. D) None of the above. Show Answer Correct Answer: C) An ion not involved in the redox reaction. 23. Which of these metals is the least easily oxidized? A) Na. B) Au. C) Ag. D) Ca. E) Fe. Show Answer Correct Answer: B) Au. 24. A redox reaction is NOT: A) All reactions. B) A combustion reaction. C) A reduction-oxidation reaction. D) A reaction in which electrons are transferred from one atom to another. Show Answer Correct Answer: A) All reactions. 25. Which of the following characterizes the oxidation-reduction relationship? A) Element losing electrons is oxidized, element gaining electrons is reduced. B) Element gaining electrons is losing hydrogen, element losing electrons is gaining hydrogen. C) Element losing electrons is losing oxygen, element gaining electrons is gaining oxygen. D) Element gaining electrons is oxidized, element losing electrons is reduced. Show Answer Correct Answer: A) Element losing electrons is oxidized, element gaining electrons is reduced. 26. What is the precipitate formed when you mix silver nitrate with copper chloride? A) Copper chloride. B) Copper nitrate. C) Silver chloride. D) Silver nitrate. Show Answer Correct Answer: C) Silver chloride. 27. In which of the following does hydrogen have a negative oxidation number? A) NH3. B) CH4. C) NaH. D) H2O2. Show Answer Correct Answer: C) NaH. 28. What is a reducing agent? A) It is the species that gets oxidized loses electrons. B) It is the species that gets reduced gains electrons. C) It is the species that destroys electrons. D) It is the species that creates electrons. Show Answer Correct Answer: A) It is the species that gets oxidized loses electrons. 29. The sum of the oxidation numbers in Na$_{2}$CO$_{3}$ is equivalent to A) 0. B) -1. C) -2. D) +1. Show Answer Correct Answer: A) 0. 30. Gaining oxygen is an example of ..... A) Oxidation. B) Reduction. C) All the above. D) None of the above. Show Answer Correct Answer: A) Oxidation. 31. In a redox reaction, the substance that loses electrons is called the: A) Oxidant. B) Catalyst. C) Inhibitor. D) Reductant. Show Answer Correct Answer: A) Oxidant. 32. What is the oxidation state of sulfur in $\text{H}_2\text{SO}_4$ A) +4. B) +8. C) +2. D) +6. Show Answer Correct Answer: D) +6. 33. Name the oxidising agent in the following reaction:nitrogen + hydrogen $\rightarrow$ ammonia A) Nitrogen. B) Hydrogen. C) Ammonia. D) None of the above. Show Answer Correct Answer: A) Nitrogen. 34. Iron rusts in the presence of oxygen and water. Which method causes iron to rust faster? A) Coating iron with tin. B) Galvanising iron with zinc. C) Touching iron with lead. D) Connecting iron to magnesium. Show Answer Correct Answer: C) Touching iron with lead. 35. Which element was reduced in the reaction below?Na + PbCl$_{2 }$$\rightarrow$ Pb + NaCl A) Na. B) No element was reduced. C) Cl. D) Pb. Show Answer Correct Answer: D) Pb. 36. In which of the following, the oxidation number of chlorine is +5? A) ClO$_{2}$$^{-}$. B) ClO$^{-}$. C) ClO$_{3}$$^{-}$. D) Cl$^{-}$. Show Answer Correct Answer: C) ClO$_{3}$$^{-}$. 37. The following chemical equation represents the extraction of silicon from quartz using coke. SiO$_{2}$ + C $\rightarrow$ Si + CO$_{2}$What is the change in oxidation number of silicon? A) 0 to +4. B) 0 to +2. C) +4 to 0. D) +2 to 0. Show Answer Correct Answer: C) +4 to 0. 38. What happens in a displacement reaction? A) A less reactive metal displaces a more reactive one. B) A more reactive metal displaces a less reactive one. C) Both metals precipitate out as solids. D) No displacement occurs. Show Answer Correct Answer: B) A more reactive metal displaces a less reactive one. 39. For which of the following species is the oxidation number of oxygen the lowest? A) Na$_{2}$O$_{2}$. B) O$_{2}$. C) H$_{2}$SO$_{4}$. D) H$_{2}$O$_{2}$. Show Answer Correct Answer: B) O$_{2}$. 40. Which salt will be produced if magnesium react with hydrochloric acid? A) Magnesium oxide. B) Magnesium chloride. C) Magnesium sulfate. D) Magnesium sulfide. Show Answer Correct Answer: B) Magnesium chloride. 41. Define reduction. A) Gain of electron. B) Loss of electron. C) All the above. D) None of the above. Show Answer Correct Answer: A) Gain of electron. 42. Which of the following cannot occur during oxidation? A) Gain of oxygen. B) Decrease in oxidation number. C) Loss of hydrogen. D) Donation of electrons. Show Answer Correct Answer: B) Decrease in oxidation number. 43. What are the oxidation numbers of sodium and iodine in potassium triiodide, KI$_{3}$? A) K = +1; I = 0. B) K = +1; I =-1. C) K =-1; I =-3. D) K = +1; I =-2/3. E) K = +1; I =-1/3. Show Answer Correct Answer: E) K = +1; I =-1/3. 44. Hydrogen sulfide gas is bubbled through a solution of potassium hydroxide; what is the net ion equation? A) H$^{+}$ + OH$^{-}$$\rightarrow$ H$_{2}$O. B) H$_{2}$S + KOH $\rightarrow$H$_{2}$O + K$_{2}$S. C) H$_{2}$S + OH$^{-}$ $\rightarrow$ H$_{2}$O + S$^{2-}$. D) No rxn. Show Answer Correct Answer: C) H$_{2}$S + OH$^{-}$ $\rightarrow$ H$_{2}$O + S$^{2-}$. 45. What is the oxidation number of the chromium element in potassium dichromate (VI), $K_2Cr_2O_7$ A) +6. B) +3. C) +5. D) +2. Show Answer Correct Answer: A) +6. 46. What is the role of electrons in redox reactions? A) Electrons are not involved in chemical reactions. B) Electrons are transferred between reactants. C) Electrons are only involved in ionic bonding. D) Electrons are solely responsible for heat generation. Show Answer Correct Answer: B) Electrons are transferred between reactants. 47. Which of these chemical reactions is an oxidation-reduction reaction? A) Fe + S $\rightarrow$ FeS. B) AgNO$_{3}$ + NaCl $\rightarrow$AgCl + NaNO$_{3}$. C) CO$_{2}$ + H$_{2}$O $\rightarrow$ H$_{2}$CO$_{3}$. D) H$_{2}$SO$_{4}$ + 2NaOH $\rightarrow$ Na$_{2}$SO$_{4}$ + 2H$_{2}$O. Show Answer Correct Answer: A) Fe + S $\rightarrow$ FeS. 48. How are electrons treated in the balancing of redox equations? A) Only considered in acid-base reactions. B) Assumed to be lost in the reaction. C) Counted to ensure the same number on both sides of the equation. D) Ignored, as they are not important. Show Answer Correct Answer: C) Counted to ensure the same number on both sides of the equation. 49. Product of electrolysis:An aqueous solution of silver nitrate with platinum electrodes A) Anode:AgCathode:NO$_{3}$. B) Anode:NO$_{3}$Cathode:Ag. C) Anode:O$_{2}$Cathode:Ag. D) None of these. Show Answer Correct Answer: C) Anode:O$_{2}$Cathode:Ag. 50. What is the anode in a galvanic cell? A) The electrode where oxidation occurs. B) The electrode that attracts anions. C) The electrode where reduction occurs. D) The electrode that attracts cations. Show Answer Correct Answer: A) The electrode where oxidation occurs. 51. Oxidation number of any free element is always ..... A) 1. B) 3. C) 2. D) 0. Show Answer Correct Answer: D) 0. 52. 2Pb(NO$_{3}$)$_{2}$ $\rightarrow$ 2PbO + 4NO$_{2}$ + O$_{2}$ A) Combustion. B) Synthesis. C) Single Displacement. D) Decomposition. Show Answer Correct Answer: D) Decomposition. 53. Which of the following is a characteristic feature of a redox reaction? A) It results in the formation of a precipitate. B) It involves the transfer of electrons between reactants. C) It only occurs in basic solutions. D) It involves the exchange of protons between reactants. Show Answer Correct Answer: B) It involves the transfer of electrons between reactants. 54. What happens to the oxidation number of an element that is reduced? A) The oxidation number decreases. B) The oxidation number fluctuates. C) The oxidation number remains the same. D) The oxidation number increases. Show Answer Correct Answer: A) The oxidation number decreases. 55. In the reaction 2H$_{2}$ + O$_{2}$ $\rightarrow$ 2H$_{2}$O, which element is reduced? A) Hydrogen. B) Oxygen. C) Both. D) None. Show Answer Correct Answer: B) Oxygen. 56. What is the stoichiometry of KMnO4 in a titration with Fe2+? A) 1:3. B) 1:6. C) 1:5. D) 1:4. Show Answer Correct Answer: C) 1:5. 57. In a redox reaction, one substance gets oxidised while other gets A) Reduced. B) Neutralised. C) Combined. D) Oxidised. Show Answer Correct Answer: A) Reduced. 58. How does the oxidation state of Li change in the following reaction?Li(s) + NaOH(aq) $\rightarrow$ LiOH(aq) + Na(s) A) It goes from 0 to-1. B) It goes from +1 to +2. C) It does not change. D) It goes from 0 to +1. Show Answer Correct Answer: D) It goes from 0 to +1. 59. What coefficient would Fe$^{+2}$ have in the following reaction? ..... Al + ..... Fe$^{+2}$ $\rightarrow$ ..... Al$^{+3}$ + ..... Fe A) 6. B) 3. C) 1. D) 2. Show Answer Correct Answer: B) 3. 60. What is the oxidation state of hydrogen in compounds? A) +2. B) +1. C) -1. D) 0. Show Answer Correct Answer: B) +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 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 8Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 9 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books