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 5 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 5 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. Gain of electrons is ..... A) Oxidation. B) Reduction. C) Neither. D) Neutralization. Show Answer Correct Answer: B) Reduction. 2. Anions get discharged by ..... electrons at the ..... A) Gaining, anode. B) Gaining, cathode. C) Losing, cathode. D) Losing, anode. Show Answer Correct Answer: D) Losing, anode. 3. Balance the following reaction in acidic solutionI$^{-}$ + HNO$_{2}$ $\rightarrow$ NO + I$_{2}$ A) 2I$^{-}$ + HNO$_{2}$ + H$_{2}$O + 5e$^{-}$ $\rightarrow$ NO$_{2}$ + I$_{2}$ + 3H$^{+}$. B) 2I$^{-}$ + HNO$_{2}$ + H$_{2}$O + 5e$^{-}$ $\rightarrow$ NO + I$_{2}$ + 3H$^{+}$. C) I$^{-}$ + HNO$_{2}$ + H$_{2}$O + 5e$^{-}$ $\rightarrow$ NO$_{2}$ + I$_{2}$ + 3H$^{+}$. D) 2I$^{-}$ + HNO$_{2}$ + H$_{2}$O + 4e$^{-}$ $\rightarrow$ NO + I$_{2}$ + 3H$^{+}$. Show Answer Correct Answer: B) 2I$^{-}$ + HNO$_{2}$ + H$_{2}$O + 5e$^{-}$ $\rightarrow$ NO + I$_{2}$ + 3H$^{+}$. 4. Which of the following is not a step for balancing redox reactions in acidic solutions? A) Balance elements other than H and O. B) Balance hydrogen with H$^{+}$. C) Balance charge with electrons. D) Balance oxygen with O$^{2-}$. Show Answer Correct Answer: D) Balance oxygen with O$^{2-}$. 5. Which of the following reactions is an example of a disproportionation reaction? A) C + O2 $\rightarrow$ CO2. B) Zn + Cu2+ $\rightarrow$ Zn2+ + Cu. C) 2H2O2 $\rightarrow$ 2H2O + O2. D) 2Na + Cl2 $\rightarrow$ 2NaCl. Show Answer Correct Answer: C) 2H2O2 $\rightarrow$ 2H2O + O2. 6. Which of the following reaction is not a redox reaction? A) Single displacement. B) Thermal decomposition. C) Rusting. D) Electrolysis. Show Answer Correct Answer: B) Thermal decomposition. 7. Oxidation state of any free element is always ..... A) 3. B) 0. C) 1. D) 2. Show Answer Correct Answer: B) 0. 8. Metals are extracted from their ores.What is the name of the ores that contain Fe$_{2}$O$_{3}$ as the main mineral? A) Magnetite. B) Malachite. C) Hematite. D) Cassiterite. Show Answer Correct Answer: C) Hematite. 9. Gaining hydrogen is an example of ..... A) Oxidation. B) Reduction. C) All the above. D) None of the above. Show Answer Correct Answer: B) Reduction. 10. How do fuel cells differ from galvanic cells? A) Fuel cells require a continuous supply of reactants. B) Galvanic cells convert chemical energy into electrical energy more efficiently. C) Fuel cells do not involve redox reactions. D) Galvanic cells require an external circuit to operate. Show Answer Correct Answer: A) Fuel cells require a continuous supply of reactants. 11. In the reaction Zn + Cu2+ $\rightarrow$ Zn2+ + Cu, which species is reduced? A) Zinc. B) None of the above. C) Copper ion. D) Copper metal. Show Answer Correct Answer: C) Copper ion. 12. In the reaction @@ext{Zn} + ext{CuSO} ..... 4 ightarrow ext{ZnSO} ..... 4 + ext{Cu}@@, which element is reduced? A) Oxygen (O). B) Zinc (Zn). C) Sulfur (S). D) Copper (Cu). Show Answer Correct Answer: D) Copper (Cu). 13. What is the oxidizing agent of this reaction?(The reactant that is reduced.)3Mg + N$_{2}$$\rightarrow$ Mg$_{3}$N$_{2}$ A) MgN. B) Mg$_{3}$N$_{2}$. C) N$_{2}$. D) Mg. Show Answer Correct Answer: C) N$_{2}$. 14. Which of the following is the correct balanced redox equation for the reaction between $Fe^{2+}$ $MnO_4^-$ A) $5Fe^{2+} + MnO_4^-+ 4H^+ \rightarrow 5Fe^{3+} + Mn^{2+} + 2H_2O$. B) $5Fe^{2+} + MnO_4^-+ 4H^+ \rightarrow 5Fe^{3+} + Mn^{2+} + 4H_2O$. C) $5Fe^{2+} + MnO_4^-+ 8H^+ \rightarrow 5Fe^{3+} + Mn^{2+} + 2H_2O$. D) $5Fe^{2+} + MnO_4^-+ 8H^+ \rightarrow 5Fe^{3+} + Mn^{2+} + 4H_2O$. Show Answer Correct Answer: D) $5Fe^{2+} + MnO_4^-+ 8H^+ \rightarrow 5Fe^{3+} + Mn^{2+} + 4H_2O$. 15. Identify the oxidation number of nitrogen in NH3. A) +3. B) -3. C) +1. D) -1. Show Answer Correct Answer: B) -3. 16. Substance that reduces another substance by losing electrons. A) Reducing agent. B) Oxidizing agent. C) Conbustion. D) Oxidation number. Show Answer Correct Answer: A) Reducing agent. 17. What is the oxidation number of sulfur in H$_{2}$SO$_{4}$? A) +4. B) 0. C) +6. D) +1. Show Answer Correct Answer: C) +6. 18. A half equation is one that ..... A) Shows reduction. B) Shows everything in a redox reaction. C) Only shows half of an equation. D) Shows either reduction or oxidation. Show Answer Correct Answer: D) Shows either reduction or oxidation. 19. In the reaction 2Mg$_{(s)}$ + O$_{2(g)}$ $\rightarrow$ 2MgO$_{(s)}$, which is the reductant? A) Mg$_{(s)}$. B) O$_{2(g)}$. C) MgO$_{(s)}$. D) None of the above. Show Answer Correct Answer: A) Mg$_{(s)}$. 20. Which is a salt? A) Copper. B) Copper oxide. C) Copper hydroxide. D) Copper sulphate. Show Answer Correct Answer: D) Copper sulphate. 21. H2O2$\rightarrow$ H2O +O2 is an example of A) Decomposition reaction. B) Displacement reaction. C) Combination reaction. D) Disproportionation reaction. Show Answer Correct Answer: D) Disproportionation reaction. 22. Loss of electrons is ..... A) Double replace. B) Reduction. C) Neutralization. D) Oxidation. Show Answer Correct Answer: D) Oxidation. 23. A reducing agent causes the other chemical species to undergo reduction, so it will lose electrons because it is oxidised itself. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: A) True. 24. In a redox reaction, number of oxygen and hydrogen atoms are balanced by adding ..... A) H$_{2}$O. B) OH$^{-}$. C) H$^{+}$. D) H$_{2}$O$_{2}$. Show Answer Correct Answer: A) H$_{2}$O. 25. Describe the reduction mechanism of chromium in potassium dichromate. A) Chromium is oxidized from Cr(III) to Cr(VI) in potassium dichromate. B) Chromium is reduced from Cr(IV) to Cr(II) in potassium dichromate. C) Chromium is reduced from Cr(VI) to Cr(III) in potassium dichromate. D) Chromium remains in the Cr(VI) state in potassium dichromate. Show Answer Correct Answer: C) Chromium is reduced from Cr(VI) to Cr(III) in potassium dichromate. 26. Balance the following ACIDIC reactions using the half-reaction method.MnO$_{4}$$^{-}$ + H$^{+}$ + C$_{2}$O$_{4}$$^{2-}$ $\rightarrow$ Mn$^{2+}$ + CO$_{2}$Water is a product of this reaction. What is the coefficient of water in the final balanced equation? A) 5. B) 16. C) 2. D) 8. Show Answer Correct Answer: D) 8. 27. The incomplete equation shows a reaction. CuCO$_{3}$ + H$_{2}$SO$_{4}$ $\rightarrow$ products What are the products of this reaction? A) Copper(II) oxide, sulphur dioxide, water. B) Copper(II) sulphate, carbon dioxide, hydrogen. C) Copper(II) oxide, sulphur dioxide, hydrogen. D) Copper(II) sulphate, carbon dioxide, water. Show Answer Correct Answer: D) Copper(II) sulphate, carbon dioxide, water. 28. Acidified potassium manganate(VII) is usually used as A) A reducing agent. B) An oxidising agent. C) Both an oxidising and a reducing agent. D) A dehydrating agent. Show Answer Correct Answer: B) An oxidising agent. 29. What element's don't have oxidation numbers? A) Noble gases. B) Halogens. C) Alkaline earth metals. D) Alkali metals. Show Answer Correct Answer: A) Noble gases. 30. What is the oxidation number of oxygen in most compounds? A) +1. B) -2. C) 0. D) -1. Show Answer Correct Answer: B) -2. 31. Which of the following elements will form a cation? A) Arsenic. B) Bromine. C) Fluorine. D) Copper. Show Answer Correct Answer: D) Copper. 32. In electrochemistry, the site where oxidation occurs is called the ..... A) Cathode. B) Electrode. C) Anode. D) Ion. Show Answer Correct Answer: C) Anode. 33. Which type of redox reaction is shown below? KClO$_{3}$ $\rightarrow$ KCl + O$_{2}$ (a) A) A. decomposition. B) Single replacement. C) Combustion. D) Synthesis. Show Answer Correct Answer: A) A. decomposition. 34. In the reaction 2Mg + O2 $\rightarrow$ 2MgO, what is being oxidized? A) None of the above. B) Magnesium. C) Oxygen. D) Magnesium oxide. Show Answer Correct Answer: B) Magnesium. 35. In the reaction Zn + 2HCl $\rightarrow$ ZnCl$_{2}$ + H$_{2}$which element, if any, is oxidized? A) Zinc. B) Hydrogen. C) Chlorine. D) None. Show Answer Correct Answer: A) Zinc. 36. What is the colour change of acidified KMnO$_{4}$(aq) solution when serving as oxidizing agent? A) From purple to blue. B) From orange to green. C) From colourless to purple. D) From green to orange. Show Answer Correct Answer: C) From colourless to purple. 37. Explain the significance of oxidation states in redox reactions. A) Oxidation states are used to measure temperature changes in reactions. B) Oxidation states are irrelevant in redox reactions. C) Oxidation states only apply to acids and bases. D) Oxidation states are significant in redox reactions as they help identify electron transfer, determine which species are oxidized or reduced, and facilitate the balancing of redox equations. Show Answer Correct Answer: D) Oxidation states are significant in redox reactions as they help identify electron transfer, determine which species are oxidized or reduced, and facilitate the balancing of redox equations. 38. What is the fundamental mechanism behind redox reactions? A) Photon transfer. B) Proton transfer. C) Electron transfer. D) Neutron transfer. Show Answer Correct Answer: C) Electron transfer. 39. What is the cathode in a galvanic cell? A) The electrode that attracts anions. B) The electrode where reduction occurs. C) The electrode where oxidation occurs. D) The electrode that attracts cations. Show Answer Correct Answer: B) The electrode where reduction occurs. 40. Which statement is true:Mg $\rightarrow$ Mg$^{2+}$ + 2e$^{-}$ A) Mg gains 2 electrons. B) Mg loses 2 electrons. C) Mg$^{2+}$ loses 2 electron. D) Mg loses 1 electron. Show Answer Correct Answer: C) Mg$^{2+}$ loses 2 electron. 41. ..... is reduced in the following reaction:Cr$_{2}$O$_{7}$$^{2-}$ + 6 S$_{2}$O$_{3}$$^{2-}$+ 14 H$^{+ }$$\rightarrow$ 2 Cr$^{3+ }$+ 3 S$_{4}$O$_{6}$$^{2-}$+ 7 H$_{2}$O A) S$_{4}$O$_{6}$$^{2-}$. B) O$^{2-}$. C) Cr$^{6+}$. D) S$^{2+}$. E) H$^{+}$. Show Answer Correct Answer: C) Cr$^{6+}$. 42. Which element is oxidized?H$_{2}$S + Cl$_{2}$ $\rightarrow$ 2HCl + S A) Cl. B) Not a redox reaction. C) S. D) H. Show Answer Correct Answer: C) S. 43. What is the oxidation state of Cl in ClO$^{-}$? A) +2. B) 0. C) -1. D) +1. Show Answer Correct Answer: D) +1. 44. In this equation, CuCl$_{2}$ $_{}$+ NaOH $\rightarrow$ Cu(OH)$_{2}$ + NaClWhich product is insoluble? A) Sodium hydroxide. B) Sodium chloride. C) Copper(II) chloride. D) Copper(II) hydroxide. Show Answer Correct Answer: D) Copper(II) hydroxide. 45. Which of the following methods is commonly used for corrosion prevention? A) Electroplating. B) Fermentation. C) Distillation. D) Combustion. Show Answer Correct Answer: A) Electroplating. 46. ..... is reduced in the following reaction:Cr$_{2}$O$_{7}$$^{2-}$ + 6 S$_{2}$O$_{3}$$^{2-}$ + 14H$^{+ }$ > 2Cr$^{3+}$ + 3S$_{4}$O$_{6}$$^{2-}$ + 7H$_{2}$O A) H$^{+}$. B) S$_{2}$O$_{3}$$^{2-}$. C) Cr$_{2}$O$_{7}$$^{2-}$. D) S$_{4}$O$_{6}$$^{2-}$. Show Answer Correct Answer: C) Cr$_{2}$O$_{7}$$^{2-}$. 47. Which reactant is oxidized in the following reaction:Ba(s) + O$_{2}$(g) $\rightarrow$ BaO(s) A) BaO. B) O$_{2}$. C) Ba. D) None of the above. Show Answer Correct Answer: C) Ba. 48. How many electrons are transferred in the reaction below?3 Mg + 2 AlCl$_{3}$ $\rightarrow$ 3 MgCl$_{2}$ + 2 Al A) 2 electrons. B) 3 electrons. C) 6 electrons. D) 10 electrons. Show Answer Correct Answer: C) 6 electrons. 49. In a galvanic cell, which electrode is the anode? A) The electrode where reduction occurs. B) The electrode with the higher potential. C) The electrode connected to the salt bridge. D) The electrode where oxidation occurs. Show Answer Correct Answer: D) The electrode where oxidation occurs. 50. What is the name given to the solution that is being electrolysed? A) Electrolyte. B) Electric solution. C) Mineral solution. D) Salt solution. Show Answer Correct Answer: A) Electrolyte. 51. Which of the following is not one of the possible oxidation state Cl atom? A) +7. B) +1. C) -2. D) -1. Show Answer Correct Answer: C) -2. 52. WRITE THIS OUT ON PAPER, YOU MAY USE THE ANSWER TO THIS PROBLEM AGAIN IN ANOTHER QUESTION:Balance the following reactions using the half-reaction method.MnO$_{4}$$^{-}$(aq) + H$^{+}$(aq) + I$^{-}$ (aq) $\rightarrow$ Mn$^{2+}$(aq) + I$_{2}$(s)How many electrons did you cross out on both side? A) 5 e$^{-}$. B) 10 e$^{-}$. C) 2 e$^{-}$. D) 1 e$^{-}$. Show Answer Correct Answer: B) 10 e$^{-}$. 53. WRITE THIS OUT ON PAPER, YOU MAY USE THE ANSWER TO THIS PROBLEM AGAIN IN ANOTHER QUESTION:Consider the following REDOX reaction:Cl$_{2}$(g) $\rightarrow$ ClO$^{-}$(aq) + Cl$^{-}$(aq) (basic solution)How many OH$^{-}$ molecules did you add to the reactant side of this reaction when balancing? A) 4. B) 1. C) 2. D) 3. Show Answer Correct Answer: A) 4. 54. Which of these biological processes involves redox reactions? A) Protein synthesis. B) Cellular respiration. C) DNA replication. D) Osmosis. Show Answer Correct Answer: B) Cellular respiration. 55. Which substance is reduced in the following reaction?2PbSO$_{4}$ + H$_{2}$O $\rightarrow$ Pb + PbO$_{2}$ + 2H$_{2}$SO$_{4}$ A) Pb. B) PbSO$_{4}$. C) PbO$_{2}$. D) None of the above. Show Answer Correct Answer: B) PbSO$_{4}$. 56. Reduction takes place at the ..... A) Cathode. B) Anion. C) Anode. D) Salt bridge. Show Answer Correct Answer: A) Cathode. 57. Which energy conversion shown below takes place in a voltaic cell? A) Mechanical to chemical. B) Mechanical to electrical. C) Chemical to electrical. D) Electrical to chemical. Show Answer Correct Answer: C) Chemical to electrical. 58. Which quantities are conserved in all oxidation reduction reaction? A) Charge only. B) Mass only. C) Both charge and mass. D) Neither charge nor mass. Show Answer Correct Answer: C) Both charge and mass. 59. What is the name of the precipitate formed in the reaction of calcium sulfide and aluminum nitrate A) Aluminum sulfide. B) No ppt is formed. C) Calcium nitrate. D) Aluminum nitrate. Show Answer Correct Answer: A) Aluminum sulfide. 60. What is the oxidation number of chlorine in NaClO? A) +1. B) +3. C) 0. D) -1. Show Answer Correct Answer: A) +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 4Class 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