This quiz works best with JavaScript enabled. Home > Class 11 > Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions – Quiz 3 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 3 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. If in a reaction, copper is reduced; its number of electrons has: A) Increased. B) Decreased. C) Remained constant. D) Varied randomly. Show Answer Correct Answer: A) Increased. 2. In a redox reaction, what is the role of the oxidizing agent? A) The oxidizing agent donates electrons and is oxidized in the process. B) The oxidizing agent accepts electrons and is reduced in the process. C) The oxidizing agent remains unchanged throughout the reaction. D) The oxidizing agent increases the temperature of the reaction. Show Answer Correct Answer: B) The oxidizing agent accepts electrons and is reduced in the process. 3. Which of the following best describes a redox reaction? A) A chemical reaction where electrons are transferred. B) A chemical reaction where electrons are lost. C) A chemical reaction where electrons are gained. D) None of the above. Show Answer Correct Answer: A) A chemical reaction where electrons are transferred. 4. How can you identify a redox reaction? A) Look for changes in oxidation states of elements in the reactants and products. B) Identify the presence of catalysts in the reaction. C) Check if the reaction involves a gas release. D) Observe the temperature change during the reaction. Show Answer Correct Answer: A) Look for changes in oxidation states of elements in the reactants and products. 5. What is a correct half reaction for the following reaction:2 Al + N$_{2 }$$\rightarrow$ 2 AlN A) Al$^{0}$ + 3 e$^{-}$ $\rightarrow$ Al$^{+3}$. B) N$^{0}$ $\rightarrow$ N$^{+2}$ + 2 e$^{-1}$. C) Al$^{+3}$ + 3 e$^{-1}$ $\rightarrow$ Al$^{0}$. D) N$^{0}$ + 3 e$^{-1}$ $\rightarrow$ N$^{-3}$. Show Answer Correct Answer: D) N$^{0}$ + 3 e$^{-1}$ $\rightarrow$ N$^{-3}$. 6. What is the oxidation state of carbon in CO2? A) +4. B) 0. C) -4. D) +2. Show Answer Correct Answer: A) +4. 7. Which reducing agent is used in the production of iron in a blast furnace? A) Carbon. B) Carbon dioxide. C) Carbon monoxide. D) Calcium carbonate (limestone). Show Answer Correct Answer: C) Carbon monoxide. 8. During an oxidation-reduction reaction, the number of electrons gained is A) Equal to the number of electrons lost. B) Equal to the number of protons gained. C) Less than the number of electrons lost. D) Less than the number of protons gained. Show Answer Correct Answer: A) Equal to the number of electrons lost. 9. WRITE THIS OUT ON PAPER, YOU MAY USE THE ANSWER TO THIS PROBLEM AGAIN IN ANOTHER QUESTION:Balance the following ACIDIC reactions using the half-reaction method.MnO$_{4}$$^{-}$(aq) + H$^{+}$(aq) + I$^{-}$ (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) 2. D) 16. Show Answer Correct Answer: A) 8. 10. Which of the following is a redox reaction? A) $\text{HCl} + \text{NaOH} \rightarrow \text{NaCl} + \text{H}_2\text{O}$. B) $\text{AgNO}_3 + \text{NaCl} \rightarrow \text{AgCl} + \text{NaNO}_3$. C) $\text{Zn} + \text{CuSO}_4 \rightarrow \text{ZnSO}_4 + \text{Cu}$. D) $\text{BaCl}_2 + \text{Na}_2\text{SO}_4 \rightarrow \text{BaSO}_4 + 2\text{NaCl}$. Show Answer Correct Answer: C) $\text{Zn} + \text{CuSO}_4 \rightarrow \text{ZnSO}_4 + \text{Cu}$. 11. What is a correct half-reaction of this equation, Cu$^{+}$+ Fe $\rightarrow$ Fe$^{3+}$+ Cu? A) Cu$^{+}$ $\rightarrow$ Cu. B) Fe $\rightarrow$ Fe$^{3+}$. C) 3Cu$^{+}$ + 3e$^{-}$$\rightarrow$ 3Cu. D) Fe + 3e$^{-}$$\rightarrow$ Fe$^{3+}$. Show Answer Correct Answer: C) 3Cu$^{+}$ + 3e$^{-}$$\rightarrow$ 3Cu. 12. What does the mnemonic 'OILRIG' stand for? A) Oxidation is light, reduction is gravity. B) Oxygen in layers, reduction in gas. C) Oxidation is loss of electrons, reduction is gain of electrons. D) Oxygen is light, reduction is gain. Show Answer Correct Answer: C) Oxidation is loss of electrons, reduction is gain of electrons. 13. Explain the significance of the color change in KMnO4 titrations. A) The color change in KMnO4 titrations signifies the endpoint, indicating complete reaction of the analyte. B) The color change is irrelevant to the titration process. C) The color change shows the temperature of the solution. D) The color change indicates the presence of excess KMnO4. Show Answer Correct Answer: A) The color change in KMnO4 titrations signifies the endpoint, indicating complete reaction of the analyte. 14. What is the oxidation state of fluorine in compounds? A) +2. B) +1. C) 0. D) -1. Show Answer Correct Answer: D) -1. 15. An oxidizing agent is: A) Remains unchanged. B) Oxidized. C) Reduced. D) None of the above. Show Answer Correct Answer: C) Reduced. 16. 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. 17. Indicate the oxidation number of phosphorus in each of the following compounds:HPO3 A) +5. B) -5. C) +3. D) -1. E) +1. Show Answer Correct Answer: A) +5. 18. A compound having +2 oxidation state of O is A) H2O. B) H2O2. C) OF2. D) O2F2. Show Answer Correct Answer: C) OF2. 19. What is the oxidation number of oxygen in OF$_{2 }$molecule? A) -1. B) +1. C) -2. D) +2. Show Answer Correct Answer: D) +2. 20. 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. 21. In the redox reaction $MnO_4^-+ 8H^+ + 5e^-\rightarrow Mn^{2+} + 4H_2O$ $MnO_4^-$ A) Oxidation. B) Reduction. C) Precipitation. D) Neutralization. Show Answer Correct Answer: B) Reduction. 22. Which of the following elements does not show disproportionation tendency? A) Cl. B) F. C) I. D) Br. Show Answer Correct Answer: B) F. 23. 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. 24. 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. 25. Which half-reaction equation represents the reduction of a potassium ion? A) K$^{+}$ + e$^{-}$ $\rightarrow$ K. B) K + e$^{-}$ $\rightarrow$ K$^{+}$. C) K$^{+}$ $\rightarrow$ K + e$^{-}$. D) K $\rightarrow$ K$^{+}$ + e$^{-}$. Show Answer Correct Answer: A) K$^{+}$ + e$^{-}$ $\rightarrow$ K. ← PreviousNext →Related 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 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 9Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 10Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 11 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books