This quiz works best with JavaScript enabled. Home > Class 11 > Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions – Quiz 31 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 31 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. Which oxidation state shown by alkali metals? A) -1. B) +2. C) -2. D) +1. Show Answer Correct Answer: D) +1. 2. As an element is oxidized, its oxidation number A) Increases as electrons are gained. B) Decreases as electrons are gained. C) Decreases as electrons are lost. D) Increases as electrons are lost. Show Answer Correct Answer: C) Decreases as electrons are lost. 3. Determine the oxidation number of each element in SF$_{6}$. A) S:+6, F:-1. B) S:+6, F:-6. C) S:+1, F:-1. D) F:-6, S:+1. Show Answer Correct Answer: A) S:+6, F:-1. 4. What is the oxidation state of nitrogen in the Haber process? A) -2. B) -3. C) 0. D) -1. Show Answer Correct Answer: B) -3. 5. What is the oxidation number of Cr in Cr$_{2}$O$_{7}$$^{2-}$? A) +14. B) +6. C) -6. D) -14. Show Answer Correct Answer: B) +6. 6. What does the term 'electropositivity' refer to? A) The tendency of an atom to lose electrons. B) The tendency of an atom to form ionic bonds. C) The ability of an atom to form covalent bonds. D) The ability of an atom to gain electrons. Show Answer Correct Answer: A) The tendency of an atom to lose electrons. 7. What is the oxidation state of the hydrogen in OH$^{-}$ A) +1. B) -1. C) +2. D) -2. Show Answer Correct Answer: A) +1. 8. What is the furthest oxidative state for a primary alcohol? A) Carboxylic acid. B) Alcohol. C) Aldehyde. D) Ketone. E) Carbon dioxide. Show Answer Correct Answer: A) Carboxylic acid. 9. Which of the following most completely describes a redox reaction? A) A hydrocarbon combustion reaction. B) An oxidation and reduction reaction. C) A chemical decomposition reaction. D) A reaction resulting in electron sharing. Show Answer Correct Answer: B) An oxidation and reduction reaction. 10. What is the oxidation state of nitrogen in NH4+? A) -3. B) +1. C) 0. D) +3. Show Answer Correct Answer: A) -3. 11. What is the purpose of balancing redox equations in half-reactions? A) None of the above. B) To simplify the equation. C) To double the number of electrons. D) To ensure conservation of mass. Show Answer Correct Answer: D) To ensure conservation of mass. 12. What happens at the positive electrode? A) Positive non-metal ions are attracted. B) Positive metal ions are attracted. C) Negative non-metal ions are attracted. D) Negative metal ions are attracted. Show Answer Correct Answer: C) Negative non-metal ions are attracted. 13. How does an Mg atom turn into an Mg ion? A) It loses an electron. B) It loses two electrons. C) It gains two electrons. D) It gain an electron. Show Answer Correct Answer: B) It loses two electrons. 14. In a redox reaction, the substance that donates electrons is called the: A) Oxidizing agent. B) Reducing agent. C) Catalyst. D) Inhibitor. Show Answer Correct Answer: B) Reducing agent. 15. In a reaction, copper is reduced; its number of electrons has: A) Increased. B) Decreased. C) Remained Constant. D) Varies Randomly. Show Answer Correct Answer: A) Increased. 16. In the reaction $\text{2Fe}_2\text{O}_3 + 3\text{C} \rightarrow 4\text{Fe} + 3\text{CO}_2$ A) Iron (Fe). B) Carbon (C). C) Oxygen (O). D) Carbon dioxide ( $\text{CO}_2$. Show Answer Correct Answer: B) Carbon (C). 17. Why are the terms oxidation and reduction considered misleading? A) They are only used in biology. B) They do not always accurately describe electron transfer. C) They are outdated and no longer used. D) They always involve oxygen. Show Answer Correct Answer: B) They do not always accurately describe electron transfer. 18. Oxygen (almost) always has an oxidation number of ..... A) -1. B) 1. C) 2. D) -2. Show Answer Correct Answer: D) -2. 19. Given the equation:2 Al + 3 Cu$^{2+}$ $\rightarrow$ 2 Al$^{3+}$ + 3 CuThe reduction half-reaction is A) Al $\rightarrow$ Al$^{3+}$ + 3e$^{-}$. B) Al + 3e$^{-}$ $\rightarrow$ Al$^{3+}$. C) Cu$^{2+}$ + 2e$^{-}$ $\rightarrow$ Cu. D) Cu$^{2+}$ $\rightarrow$ Cu + 2e$^{-}$. Show Answer Correct Answer: C) Cu$^{2+}$ + 2e$^{-}$ $\rightarrow$ Cu. 20. Which element is being oxidized in the following chemical reaction?2KMnO$_{4 }$+ 5KNO$_{2}$ + 3H$_{2}$SO$_{4 }$$\rightarrow$$_{ }$2MnSO$_{4}$ + 3H$_{2}$O + 5KNO$_{3}$ + K$_{2}$SO$_{4}$ A) S. B) Mn. C) O. D) N. Show Answer Correct Answer: D) N. 21. An decrease in oxidation number. A) Oxdiation. B) Reduction. C) Redox. D) OIL RIG. Show Answer Correct Answer: B) Reduction. 22. Oxidation half-reaction involves ..... of electron/s. A) Gain. B) Loss. C) All the above. D) None of the above. Show Answer Correct Answer: B) Loss. 23. Which of the following statements is true about an electrochemical cell? A) Electrons flow from the cathode to the anode. B) Oxidation occurs at the cathode. C) Reduction occurs at the anode. D) Electrons flow from the anode to the cathode. Show Answer Correct Answer: D) Electrons flow from the anode to the cathode. 24. Which change is an oxidation? A) FeO to Fe$_{2}$O$_{3}$. B) Fe$_{2}$O$_{3}$ to FeO. C) H$_{2}$O$_{2}$ to H$_{2}$O. D) H$_{2}$O to H$_{2}$. Show Answer Correct Answer: A) FeO to Fe$_{2}$O$_{3}$. 25. A reaction where oxidation and reduction happens is a ..... A) Replacement reaction. B) Displacement reaction. C) Redox reaction. D) Competition reaction. Show Answer Correct Answer: C) Redox reaction. ← 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 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 9Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 10 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books