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 8 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 8 (60 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. Here is the oxidized half-reaction for a reaction in an acidic solution.Cr$_{2}$O$_{7}$$^{2-}$$_{(}$$_{aq}$$_{)}$ $\rightarrow$ Cr$^{3+}$$_{(}$$_{aq}$$_{)}$Determine how many electrons are needed to add to this half reaction to start the balancing process? A) 6 e$^{-}$. B) 2 e$^{-}$. C) 1 e$^{-}$. D) 3e$^{-}$. Show Answer Correct Answer: A) 6 e$^{-}$. 2. In the reaction $2Na + Cl_2 \rightarrow 2NaCl$ A) Sodium (Na). B) Chlorine (Cl 2). C) Sodium chloride (NaCl). D) None. Show Answer Correct Answer: B) Chlorine (Cl 2). 3. The sum of oxidation numbers of all the atoms in a compound ion is equal to ..... A) The charge of the high electronegative atom. B) Zero. C) The overall charge of the compound ion. D) Total number of atoms. Show Answer Correct Answer: C) The overall charge of the compound ion. 4. C in CO$_{3}$$^{2-}$? A) +2. B) +4. C) 0. D) -4. Show Answer Correct Answer: B) +4. 5. For the following example, identify the reducing agent:(The reactant that is oxidized.)H$_{2}$ + Cl$_{2}$ $\rightarrow$ 2HCl A) H$_{2}$. B) Cl$_{2}$. C) Both. D) None of the above. Show Answer Correct Answer: A) H$_{2}$. 6. Explain the concept of adding H+ and H2O to balance redox equations in acidic solutions. A) Multiply H+ and H2O to balance the equation in acidic solutions. B) Subtract H+ and H2O to balance the equation in acidic solutions. C) Divide H+ and H2O to balance the equation in acidic solutions. D) Add H+ and H2O to balance the equation in acidic solutions. Show Answer Correct Answer: D) Add H+ and H2O to balance the equation in acidic solutions. 7. What is the balanced equation for the reaction of KMnO4 with H2O2? A) 2 KMnO4 + 3 H2O2 + 4 H+ $\rightarrow$ 2 MnO4 + 3 O2 + 6 H2O. B) KMnO4 + 2 H2O2 + 2 H+ $\rightarrow$ MnO4 + 2 O2 + 2 H2O. C) KMnO4 + H2O2 + H+ $\rightarrow$ MnO2 + O2 + H2O. D) 2 KMnO4 + 5 H2O2 + 6 H+ $\rightarrow$ 2 Mn2+ + 5 O2 + 8 H2O. Show Answer Correct Answer: D) 2 KMnO4 + 5 H2O2 + 6 H+ $\rightarrow$ 2 Mn2+ + 5 O2 + 8 H2O. 8. What is the significance of the electron transfer in redox reactions? A) It is essential for energy transfer in chemical processes and is fundamental to processes like combustion and respiration. B) It helps in the formation of ionic bonds between atoms. C) It allows for the stabilization of free radicals in chemical reactions. D) It is primarily responsible for the color changes in chemical reactions. Show Answer Correct Answer: A) It is essential for energy transfer in chemical processes and is fundamental to processes like combustion and respiration. 9. What is the oxidation number of chromium in $K_2CrO_4$ A) +6. B) +2. C) +1. D) +3. Show Answer Correct Answer: A) +6. 10. The following is what type of reaction:NH$_{3}$ + HCl $\rightarrow$ NH$_{4}$Cl A) Single Replacement Replacement. B) Decomposition. C) Synthesis. D) Double Replacement Replacement. Show Answer Correct Answer: C) Synthesis. 11. Which statement defines oxidation? A) Gain of hydrogen. B) Gain of electron. C) Increase in oxidation number. D) Loss of oxygen. Show Answer Correct Answer: C) Increase in oxidation number. 12. If Magnesium is a reducing agent, therefore Magnesium is ..... A) Electron acceptor. B) Electron donor. C) All the above. D) None of the above. Show Answer Correct Answer: B) Electron donor. 13. What are spectator ions in ionic equations? A) Ions that actively participate in the reaction. B) Ions that remain unchanged and do not participate in the reaction. C) Ions that are formed as products. D) Ions that are consumed during the reaction. Show Answer Correct Answer: B) Ions that remain unchanged and do not participate in the reaction. 14. WRITE THIS OUT ON PAPER, YOU MAY USE THE ANSWER TO THIS PROBLEM AGAIN IN ANOTHER QUESTION:Balance the following ACIDIC reactions using changing oxidation number method.MnO$_{4}$$^{-}$(aq) + H$^{+}$(aq) + I$^{-}$ (aq) $\rightarrow$ Mn$^{2+}$(aq) + I$_{2}$(s)Water is a product of this reaction. What is the coefficient of water in the final balanced equation? A) 8. B) 5. C) 16. D) 2. Show Answer Correct Answer: A) 8. 15. An element's oxidation numbers changed from zero to +2 during a reaction. What happened to that element? A) It was oxidized. B) It was reduced. C) It was both oxidized and reduced. D) It was neither oxidized nor reduced. Show Answer Correct Answer: A) It was oxidized. 16. In a redox reaction, what happens to the oxidation number of the element that is reduced? A) It becomes zero. B) It remains the same. C) It decreases. D) It increases. Show Answer Correct Answer: C) It decreases. 17. How does increasing the efficiency of a fuel cell impact its operation? A) Increases the amount of fuel required. B) Reduces the environmental benefits. C) Decreases the electrical output. D) Enhances the conversion of chemical energy to electrical energy. Show Answer Correct Answer: D) Enhances the conversion of chemical energy to electrical energy. 18. Which one below is redox reaction? A) $SO_2+2H_2S\longrightarrow3S+2H_2O$. B) $NaCl+AgNO_3\longrightarrow AgCl+NaNO_3$. C) $CaCO_3+2HCl\longrightarrow CaCl_2+CO_2+H_2O$. D) $CaO+H_2O\longrightarrow Ca\left(OH\right)_2$. Show Answer Correct Answer: A) $SO_2+2H_2S\longrightarrow3S+2H_2O$. 19. The oxidation number on the central carbon atom in O=C=C=C=O and the average oxidation number of carbon, respectively are A) +2, 0. B) +4, -1.33. C) 0, +2. D) 0, +1.33. Show Answer Correct Answer: D) 0, +1.33. 20. Describe the steps to balance a redox reaction in an acidic medium. A) Balance redox reactions in acidic medium by using half-reactions, balancing atoms and charges, and combining them. B) Combine all reactants without balancing. C) Ignore the charge balance completely. D) Use only oxidation numbers to balance. Show Answer Correct Answer: A) Balance redox reactions in acidic medium by using half-reactions, balancing atoms and charges, and combining them. 21. What is the oxidation number of Cl in Cl$_{2}$? A) 0. B) -1. C) Cannot be determined. D) +1. Show Answer Correct Answer: A) 0. 22. Which expression represents the oxidation of the copper(I) ion? A) Cu $\rightarrow$ Cu$^{+}$ + e$^{-}$. B) Cu$^{+}$ + e$^{-}$$\rightarrow$ Cu$^{0}$. C) Cu$^{+}$$\rightarrow$ Cu$^{2+}$ + e$^{-}$. D) Cu$^{+}$ + e$^{-}$ $\rightarrow$ Cu$^{2+}$. Show Answer Correct Answer: C) Cu$^{+}$$\rightarrow$ Cu$^{2+}$ + e$^{-}$. 23. What is the primary function of the electrolyte in a fuel cell? A) To cool down the cell components. B) To act as a fuel source. C) To facilitate the flow of ions between the anode and cathode. D) To store electrical energy. Show Answer Correct Answer: C) To facilitate the flow of ions between the anode and cathode. 24. Solutions of acidified potassium manganate (VII) (oxidising agent) and potassium iodide (reducing agent) are mixed together. The colour of the resulting mixture is brown. This is because A) The products are colourless and brown. B) The products are puple and brown. C) The products are the same colour as the reactants. D) Potassium displaced iodine from potassium iodide. Show Answer Correct Answer: A) The products are colourless and brown. 25. In the electrolysis of an aqueous solution, which ONE of the following statements is NOT true? A) Electrons flow around the circuit from the cathode to the negative end of the battery. B) Electrons are lost by one of the species at the anode. C) Oxidation takes place at the positive electrode. D) Reduction takes place at the cathode. Show Answer Correct Answer: A) Electrons flow around the circuit from the cathode to the negative end of the battery. 26. What is the oxidation number of X in XO$_{4}$$^{-}$? A) +7. B) +5. C) +8. D) +4. Show Answer Correct Answer: A) +7. 27. Explain the difference between a cation and an anion in terms of charge. A) Cations have a positive charge, while anions have a negative charge. B) Cations have a negative charge, while anions have a positive charge. C) Both cations and anions have no charge. D) Cations are neutral, and anions are positively charged. Show Answer Correct Answer: A) Cations have a positive charge, while anions have a negative charge. 28. What is the oxidation number of O in CO$_{2}$? A) -1. B) +2. C) +4. D) -2. Show Answer Correct Answer: D) -2. 29. Which of the following is an oxidising agent? A) Potassium bromide. B) Chlorine. C) Hydrogen sulphide. D) Sulphur dioxide. Show Answer Correct Answer: B) Chlorine. 30. What is the oxidation state of manganese in K2MnO4? A) +3. B) +6. C) +4. D) +2. Show Answer Correct Answer: B) +6. 31. What is the product of the Haber process? A) Hydrogen peroxide. B) Carbon dioxide. C) Ammonia. D) Sulfuric acid. Show Answer Correct Answer: C) Ammonia. 32. What is the purpose of the salt bridge in a galvanic cell? A) To increase the voltage of the cell. B) To allow the flow of electrons between the two half-cells. C) To prevent the mixing of the solutions in the two half-cells. D) To maintain electrical neutrality by allowing the flow of ions. Show Answer Correct Answer: D) To maintain electrical neutrality by allowing the flow of ions. 33. During which process does an atom gain one or more electrons? A) Transmutation. B) Reduction. C) Oxidation. D) Neutralization. Show Answer Correct Answer: B) Reduction. 34. What is the primary process that occurs in a redox reaction? A) Proton transfer. B) Neutron transfer. C) Heat transfer. D) Electron transfer. Show Answer Correct Answer: D) Electron transfer. 35. An element undergoes oxidation when A) It gains electrons. B) Its oxidation number decreases. C) It loses oxygen. D) It loses hydrogen. Show Answer Correct Answer: D) It loses hydrogen. 36. Another name for a "oxidation-reduction" reaction is A) Nuclear reaction. B) Neutralization reaction. C) Chemical reaction. D) Redox reaction. Show Answer Correct Answer: D) Redox reaction. 37. What is the main component of a galvanic cell? A) A gas. B) Two different metals. C) A non-metal. D) A single metal. Show Answer Correct Answer: B) Two different metals. 38. The ionic equation shows the reaction between zinc (Zn) and hydrochloric acid.Zn + 2H$^{+}$ $\rightarrow$ Zn$^{2+}$ + H$_{2}$What change takes place in the zinc? A) It is reduced. B) Its oxidation state increases. C) It gains electrons. D) It gains hydrogen. Show Answer Correct Answer: B) Its oxidation state increases. 39. Which of the following statements is true about redox reactions? A) Oxidation and reduction occur simultaneously. B) Oxidation involves gain of electrons. C) Oxidation and reduction occur independently. D) Reduction involves loss of electrons. Show Answer Correct Answer: A) Oxidation and reduction occur simultaneously. 40. What is the oxidation number assigned to manganese in KMnO$_{4}$? A) $^{+}$4. B) $^{+}$2. C) $^{+}$7. D) $^{+}$3. Show Answer Correct Answer: C) $^{+}$7. 41. What is the oxidation state of Pb in PbO? A) 0. B) +2. C) -2. D) +4. Show Answer Correct Answer: B) +2. 42. Which pair could be spectator ions? A) NH$_{4}$$^{+}$ and Cl$^{-}$. B) Ca$^{+2}$ and OH$^{-}$. C) Ag+ and Br-. D) Sr$^{+2}$ and CO$_{3}$$^{-2}$. Show Answer Correct Answer: A) NH$_{4}$$^{+}$ and Cl$^{-}$. 43. In the following reaction:2CuO (s) + C (s) $\rightarrow$ 2Cu (s) + CO$_{2}$ (g)What undergoes reduction? A) Copper (Cu). B) Copper ions (Cu$^{2+}$). C) Carbon (C). D) Carbon dioxide (CO$_{2}$). Show Answer Correct Answer: B) Copper ions (Cu$^{2+}$). 44. The electrode potential for a redox reaction is: A) The difference between the electrode potential for the oxidation reaction and the reduction reaction. B) The product between the electrode potential for the oxidation reaction and the reduction reaction. C) The quotient between the electrode potential for the oxidation reaction and the reduction reaction. D) The sum between the electrode potential for the oxidation reaction and the reduction reaction. Show Answer Correct Answer: D) The sum between the electrode potential for the oxidation reaction and the reduction reaction. 45. Identify the reducing agent in the following reaction:$2Al + 3Cu^{2+} \rightarrow 2Al^{3+} + 3Cu$ A) $Al^{3+}$. B) $Al$. C) $Cu^{2+}$. D) $Cu$. Show Answer Correct Answer: B) $Al$. 46. What is the oxidation state of chromium in K$_{2}$Cr$_{2}$O$_{7}$? A) -6. B) -7. C) +7. D) +6. Show Answer Correct Answer: D) +6. 47. Why is electron flow compared to economic transactions? A) Because electrons are expensive. B) Because electrons are traded in markets. C) Because electron flow drives chemical change like money drives economic transactions. D) Because electrons are used as currency. Show Answer Correct Answer: C) Because electron flow drives chemical change like money drives economic transactions. 48. Which species functions as the oxidizing agent in the following oxidation-reduction reaction?Zn$_{(s)}$ + Pt$^{2+}$$_{(aq) }$$\rightarrow$ Pt$_{(s)}$ + Zn$^{2+}$$_{(aq)}$ A) Pt$_{(s)}$. B) Zn$^{2+}$$_{(aq)}$. C) Pt$^{2+}$$_{(aq)}$. D) Zn$_{(s)}$. E) None of these, as this is not a redox reaction. Show Answer Correct Answer: C) Pt$^{2+}$$_{(aq)}$. 49. What does the term 'redox' stand for? A) Reactive and oxygen. B) Red energy and oxidation. C) Reduction or oxygen. D) Reduction and oxidation. Show Answer Correct Answer: D) Reduction and oxidation. 50. What is the oxidation state of sulfur in HSO$_{4}$$^{-}$ A) +4. B) +8. C) +5. D) +6. Show Answer Correct Answer: D) +6. 51. What do you call is the reaction that contains the element that is oxidized? A) Reactant. B) Reductant. C) Reagent. D) Oxidant. Show Answer Correct Answer: B) Reductant. 52. What is the oxidation state of silver in the reaction with silver diamine? A) +2. B) +1. C) 0. D) -1. Show Answer Correct Answer: B) +1. 53. The production of a diol using $OsO_4$ A) Anti addition. B) Anti-Markovnikov product. C) Markovnikov product. D) Syn addition. Show Answer Correct Answer: D) Syn addition. 54. What effect does temperature have on the voltage of a galvanic cell? A) Increasing the temperature decreases the voltage of the cell. B) Increasing the temperature increases the voltage of the cell. C) Decreasing the temperature increases the voltage of the cell. D) Temperature has no effect on the voltage of a galvanic cell. Show Answer Correct Answer: B) Increasing the temperature increases the voltage of the cell. 55. In the reaction, Fe$_{2}$O$_{3}$(s) + 3CO(g) $\rightarrow$ 2Fe(l) + 3CO$_{2}$(g) A) Carbon monoxide is the oxidising agent. B) Carbon monoxide is reduced. C) Iron(III) oxide is oxidised. D) Iron(III) oxide is the oxidising agent. Show Answer Correct Answer: D) Iron(III) oxide is the oxidising agent. 56. Reduction happens at the: A) Anode. B) Salt bridge. C) Voltmeter. D) Cathode. Show Answer Correct Answer: D) Cathode. 57. Which occurs in any voltaic cell (assuming metals involved in the reaction)? A) The cathode gets smaller. B) Electrode sizes don't change. C) The anode gets smaller. D) Both electrodes get bigger. Show Answer Correct Answer: C) The anode gets smaller. 58. What is a common application of electrolysis? A) Cleaning surfaces. B) Cooking food. C) Generating heat. D) Extracting metals. Show Answer Correct Answer: D) Extracting metals. 59. Calculate the oxidation number of P in H$_{3}$P$_{2}$O$_{7 }$$^{-}$ A) -5. B) +5. C) -3. D) +3. Show Answer Correct Answer: B) +5. 60. What is oxidation state of oxygen in ozone (O3) molecule? A) -1. B) -2. C) 0. D) -1/2. Show Answer Correct Answer: C) 0. ← 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 9 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books