This quiz works best with JavaScript enabled. Home > Class 11 > Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions – Quiz 4 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 4 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. In which reaction does the oxidation state of iron remain unchanged? A) 2Fe + 3Cl$_{2}$ $\rightarrow$ 2FeCl$_{3}$. B) 2FeCl$_{2 }$ + Cl$_{2}$ $\rightarrow$ 2FeCl$_{3}$. C) Fe + 2HCl $\rightarrow$ FeCl$_{2}$ + H$_{2}$. 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. 2. What is the oxidation state of sulfur in H2SO4? A) +4. B) +2. C) +6. D) +8. Show Answer Correct Answer: C) +6. 3. What is the primary focus of redox reactions? A) Synthesis of metals. B) Formation of acids. C) Electron transfer processes. D) Combustion of fuels. Show Answer Correct Answer: C) Electron transfer processes. 4. 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. 5. Identify the oxidantH$_{2}$S + HNO$_{3}$ $\rightarrow$ NO + S + H$_{2}$O A) H$_{2}$S. B) HNO$_{3}$. C) NO. D) S. Show Answer Correct Answer: B) HNO$_{3}$. 6. What is the oxidation number of H in CH$_{4}$? A) -1. B) +1. C) -4. D) +4. Show Answer Correct Answer: B) +1. 7. 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$^{2+}$ + 4H$^{+}$ $\rightarrow$ Zn$^{2+}$ + 2V$^{3+}$ + 2H$_{2}$O. B) Zn + VO$^{2+}$ + 4H$^{+}$ $\rightarrow$ Zn$^{2+}$ + V$^{3+}$ + 2H$_{2}$O. C) Zn + 2VO$^{2+}$ + 2H$^{+}$ $\rightarrow$ Zn$^{2+}$ + 2V$^{3+}$ + H$_{2}$O. D) 2Zn + 2VO$^{2+}$ + 4H$^{+}$ $\rightarrow$ Zn$^{2+}$ + 2V$^{3+}$ + 2H$_{2}$O. Show Answer Correct Answer: A) Zn + 2VO$^{2+}$ + 4H$^{+}$ $\rightarrow$ Zn$^{2+}$ + 2V$^{3+}$ + 2H$_{2}$O. 8. 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. 9. Which of these metals is the least easily oxidized? A) Na. B) Au. C) Fe. D) Ca. E) Ag. Show Answer Correct Answer: B) Au. 10. 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. 11. Which of the following characterizes the oxidation-reduction relationship? A) Element losing electrons is losing oxygen, element gaining electrons is gaining oxygen. B) Element gaining electrons is oxidized, element losing electrons is reduced. C) Element gaining electrons is losing hydrogen, element losing electrons is gaining hydrogen. D) Element losing electrons is oxidized, element gaining electrons is reduced. Show Answer Correct Answer: D) Element losing electrons is oxidized, element gaining electrons is reduced. 12. What is the precipitate formed when you mix silver nitrate with copper chloride? A) Copper nitrate. B) Copper chloride. C) Silver chloride. D) Silver nitrate. Show Answer Correct Answer: C) Silver chloride. 13. In which of the following does hydrogen have a negative oxidation number? A) CH4. B) H2O2. C) NH3. D) NaH. Show Answer Correct Answer: D) NaH. 14. What is a reducing agent? A) It is the species that gets reduced gains electrons. B) It is the species that gets oxidized loses electrons. C) It is the species that creates electrons. D) It is the species that destroys electrons. Show Answer Correct Answer: B) It is the species that gets oxidized loses electrons. 15. The sum of the oxidation numbers in Na$_{2}$CO$_{3}$ is equivalent to A) 0. B) -2. C) +1. D) -1. Show Answer Correct Answer: A) 0. 16. 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. 17. In a redox reaction, the substance that loses electrons is called the: A) Oxidant. B) Reductant. C) Catalyst. D) Inhibitor. Show Answer Correct Answer: A) Oxidant. 18. What is the oxidation state of sulfur in $\text{H}_2\text{SO}_4$ A) +2. B) +4. C) +6. D) +8. Show Answer Correct Answer: C) +6. 19. 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. 20. Iron rusts in the presence of oxygen and water. Which method causes iron to rust faster? A) Coating iron with tin. B) Touching iron with lead. C) Galvanising iron with zinc. D) Connecting iron to magnesium. Show Answer Correct Answer: B) Touching iron with lead. 21. Which element was reduced in the reaction below?Na + PbCl$_{2 }$$\rightarrow$ Pb + NaCl A) Na. B) Pb. C) Cl. D) No element was reduced. Show Answer Correct Answer: B) Pb. 22. In which of the following, the oxidation number of chlorine is +5? A) Cl$^{-}$. B) ClO$^{-}$. C) ClO$_{2}$$^{-}$. D) ClO$_{3}$$^{-}$. Show Answer Correct Answer: D) ClO$_{3}$$^{-}$. 23. The following chemical equation represents the extraction of silicon from quartz using coke. SiO$_{2}$ + C $\rightarrow$ Si + CO$_{2}$What is the change in oxidation number of silicon? A) +2 to 0. B) +4 to 0. C) 0 to +2. D) 0 to +4. Show Answer Correct Answer: B) +4 to 0. 24. 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. 25. For which of the following species is the oxidation number of oxygen the lowest? A) Na$_{2}$O$_{2}$. B) H$_{2}$O$_{2}$. C) O$_{2}$. D) H$_{2}$SO$_{4}$. Show Answer Correct Answer: C) O$_{2}$. ← 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 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