This quiz works best with JavaScript enabled. Home > Class 11 > Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions – Quiz 28 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Class 11 Chemistry (Part Ii) Chapter 8 Redox Reactions Quiz 28 (25 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. What is oxidation number of O$_{2}$? A) 0. B) -2. C) +1. D) +2. Show Answer Correct Answer: A) 0. 2. What happens to the oxidation number of an element during oxidation? A) The oxidation number of an element decreases. B) The oxidation number of an element remains the same. C) The oxidation number of an element increases. D) The oxidation number of an element fluctuates. Show Answer Correct Answer: C) The oxidation number of an element increases. 3. Reducing agents are the substances that oxidises another substances ..... A) False. B) True. C) All the above. D) None of the above. Show Answer Correct Answer: A) False. 4. Hydrogen peroxide is not a reducing agent. A) True. B) False. C) All the above. D) None of the above. Show Answer Correct Answer: B) False. 5. How does the Haber process impact society? A) By feeding billions with fertilizer. B) By producing clean water. C) By generating renewable energy. D) By reducing air pollution. Show Answer Correct Answer: A) By feeding billions with fertilizer. 6. Oxidation happens at the A) Anode. B) Cathode. C) Salt bridge. D) Voltmeter. Show Answer Correct Answer: A) Anode. 7. What is the reduction half-reaction for the following redox reaction? Zn + HgO $\longrightarrow$ A) Zn $\longrightarrow$. B) Hg2+ + 2e-$\longrightarrow$. C) Zn + HgO. D) ZnO + Hg. Show Answer Correct Answer: B) Hg2+ + 2e-$\longrightarrow$. 8. Which of the following would oxidize an aldehyde to a carboxylic acid? A) PCC. B) $O_3$ $\left(CH_3\right)_2S$. C) $KMnO_4$. D) $OsO_4$. Show Answer Correct Answer: C) $KMnO_4$. 9. Which is the correct net ionic equation for the reaction of AgNO$_{3}$ and CaCl$_{2}$? A) Ca$^{2+}$(aq) + 2Cl$^{-}$ (aq) $\rightarrow$ CaCl(s). B) Ag$^{+}$(aq) + Cl$^{-}$ (aq) $\rightarrow$ AgCl(s). C) Ag + Cl $\rightarrow$ AgCl. D) Ag$^{+ }$+ Ca$^{2}$$^{+}$ $\rightarrow$Ag$_{2}$Ca (s). Show Answer Correct Answer: B) Ag$^{+}$(aq) + Cl$^{-}$ (aq) $\rightarrow$ AgCl(s). 10. Which statement about redox reactions is FALSE? A) Oxidation and reduction always occur together. B) Oxidation involves loss of electrons. C) The oxidizing agent is always reduced. D) The reducing agent is oxidized and gains electrons. Show Answer Correct Answer: D) The reducing agent is oxidized and gains electrons. 11. What is happening to the chemical in bold?Iron oxide + hydrogen $\rightarrow$ iron + water A) Oxidation. B) Reduction. C) All the above. D) None of the above. Show Answer Correct Answer: B) Reduction. 12. Choose the RIGHT statement A) In a redox reaction, there must be addition or removal of oxygen. B) The nature of redox reaction is the increase of element's oxidation number. C) If the oxidation number of an element changes, it is a redox reaction. D) An oxidising agent is oxidised in a redox reaction. Show Answer Correct Answer: C) If the oxidation number of an element changes, it is a redox reaction. 13. What is the significance of the purple color of KMnO4 in redox reactions? A) The purple color of KMnO4 signifies the presence of MnO4-ions in the +7 oxidation state, serving as a visual indicator in redox reactions. B) The color change signifies the reduction of KMnO4 to Mn2+ ions. C) The purple color indicates the presence of MnO2 in the +4 oxidation state. D) The purple hue is due to the presence of potassium ions in the solution. Show Answer Correct Answer: A) The purple color of KMnO4 signifies the presence of MnO4-ions in the +7 oxidation state, serving as a visual indicator in redox reactions. 14. Which element was oxidized in the reaction below?Na + PbCl$_{2 }$$\rightarrow$ Pb + NaCl A) Na. B) Pb. C) Cl. D) No element was reduced. Show Answer Correct Answer: A) Na. 15. The oxidation number of a substance in a reaction change from 0 to-1. The substance is A) Reducing agent. B) Oxidising agent. C) All the above. D) None of the above. Show Answer Correct Answer: B) Oxidising agent. 16. How does the oxidation state of manganese change during a redox reaction? A) Manganese can only be oxidized, never reduced. B) The oxidation state of manganese can only decrease during a redox reaction. C) The oxidation state of manganese remains constant in all reactions. D) The oxidation state of manganese can increase or decrease depending on whether it is oxidized or reduced. Show Answer Correct Answer: D) The oxidation state of manganese can increase or decrease depending on whether it is oxidized or reduced. 17. An element in a compound turns into an element in a chemical reaction. The element ..... A) Is definitely oxidised. B) Is definitely reduced. C) May have been oxidisied or reduced. D) Is neither oxidised nor reduced. Show Answer Correct Answer: B) Is definitely reduced. 18. Substance that is reduced is called the ..... A) Reducing agent. B) Oxidation number. C) Combustion. D) Oxidizing agentTagsNGSS.HS-PS1-2NGSS.HS-PS1-1. Show Answer Correct Answer: D) Oxidizing agentTagsNGSS.HS-PS1-2NGSS.HS-PS1-1. 19. 2MnO$_{4}$$^{-}$ + 5C$_{2}$O$_{4}$$^{2-}$ + 8H$^{+ }$$\rightarrow$ 2Mn$^{2+}$ + 10CO$_{2}$ + 4H$_{2}$OWhich species has been reduced? A) Manganate. B) Carbon. C) Oxygen. D) Hydrogen. Show Answer Correct Answer: A) Manganate. 20. 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)Which species is the result of oxidation? A) Cl$^{-}$. B) ClO$^{-}$. C) All the above. D) None of the above. Show Answer Correct Answer: B) ClO$^{-}$. 21. Which statement is true concerning an oxidation-reduction reaction? A) The reactant that is reduced is the oxidizing agent. B) The reactant which is oxidized is the oxidizing agent. C) The reactant which gains electrons is the reducing agent. D) The reactant which loses electrons is the oxidizing agent. Show Answer Correct Answer: A) The reactant that is reduced is the oxidizing agent. 22. In which substance does bromine have an oxidation number of +1? A) Br$_{2}$. B) HBr. C) HBrO. D) HBrO$_{2}$. Show Answer Correct Answer: C) HBrO. 23. What is the oxidation number of Ca in Ca$_{3}$N$_{2}$? A) +3. B) +2. C) -3. D) -2. Show Answer Correct Answer: B) +2. 24. Which is true of the activity series of metals? A) Less reactive metal replaces the more reactive metal. B) More reactive metal will be reduced. C) More reactive metal is a better reducing agent. D) The less reactive metal will be at the anode. Show Answer Correct Answer: C) More reactive metal is a better reducing agent. 25. In the reaction 4Fe + 3O2 $\rightarrow$ 2Fe2O3, which element is being reduced? A) Iron. B) Oxygen. C) Iron(III) oxide. D) None of the above. Show Answer Correct Answer: B) Oxygen. ← 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