Quiz  /  Oxidation Reduction Class 12 MCQ Questions With Answers

  • 1. 
    Which of the following is NOT an example of an oxidation reduction reaction?

  • metal rusting
  • acid neutralizing base
  • burning methane
  • photosynthesis

  • 2. 
    Which element was reduced in the reaction below?Na + PbCl2 → Pb + NaCl

  • Na
  • Pb
  • Cl
  • No element was reduced

  • 3. 
    If an atom lost electrons, it...

  • was burned
  • was reduced
  • was oxidized
  • it became negative

  • 4. 
    What is the oxidation number on the nitrogen in NO?

  • 0
  • -1
  • -2
  • +2

  • 5. 
    Which of the following has an oxidation number of zero on the chlorine atom?

  • NaCl
  • Cl2
  • Cl-
  • ClO3-

  • 6. 
    An element's oxidation numbers became more negative during a reaction. What happened to that element?

  • It was oxidized
  • It was reduced
  • It was both oxidized and reduced
  • It was neither oxidized nor reduced

  • 7. 
    An element's oxidation numbers remain the same during a reaction. What happened to that element?

  • It was oxidized
  • It was reduced
  • It was both oxidized and reduced
  • It was neither oxidized nor reduced

  • 8. 
    What is the oxidation number on the nitrogen in NO2-?

  • -1
  • +3
  • -3
  • +4

  • 9. 
    A galvanic cell was created with a Calcium and a Copper cell. Which is the correct half equation at the anode?

  • Ca2+(aq)+2e−⟺ Ca(s)Ca^{2+}\left(aq\right)+2e^-\Longleftrightarrow\ Ca\left(s\right)Ca2+(aq)+2e−⟺ Ca(s)
  • Ca++e−⟺ Ca(s)Ca^++e^-\Longleftrightarrow\ Ca\left(s\right)Ca++e−⟺ Ca(s)
  • Cu2+(aq) + e− ⟺ Cu+(aq)Cu^{2+}\left(aq\right)\ +\ e^-\ \Longleftrightarrow\ Cu^+\left(aq\right)Cu2+(aq) + e− ⟺ Cu+(aq)
  • Cu2+(aq) + 2e− ⟺ Cu(s)Cu^{2+}\left(aq\right)\ +\ 2e^-\ \Longleftrightarrow\ Cu\left(s\right)Cu2+(aq) + 2e− ⟺ Cu(s)

  • 10. 
    Batteries are an example of:

  • an electrolytic cell
  • a chemical cell
  • electrical cells
  • a galvanic cell

  • 11. 
    Reduction is the ___________ of electrons.

  • loss
  • gain
  • transfer
  • share

  • 12. 
    From the list below, which step comes first when you are balancing half-equations?

  • Add H2O to balance oxygen
  • Balance elements other that O and H
  • Balance the charge with e-
  • Add H+ to balance hydrogen

  • 13. 
    An aqueous solution of potassium iodide turns from colourless to brown. What happens to the iodide ions?

  • Iodide ions are oxidised due to gain of electrons.
  • Iodide ions are oxidised due to loss of electrons.
  • Iodide ions are reduced due to loss of electrons.
  • Iodide ions are reduced due to gain of electrons.

  • 14. 
    Which of the following elements is the strongest oxidizing agent?

  • Chlorine
  • Aluminium
  • Hydrogen
  • Lithium

  • 15. 
    In a galvanic cell, where does the oxidation reaction take place?

  • circuit
  • salt bridge
  • cathode
  • anode

  • 16. 
    What is the oxidation state of Nitrogen in N2 (g)?

  • 4
  • 6
  • 2
  • 0

  • 17. 
    Which of the following is the balanced half -reaction for the oxidation of Cu to Cu+2?

  • Cu --> Cu+2
  • Cu + 2 e- --> Cu+2
  • Cu - 2e- --> Cu+2
  • Cu --> Cu+2 + 2 e-

  • 18. 
    The oxidation number of Hydrogen in KH potassium hydride equals:

  • -1
  • +1
  • 0
  • 2

  • 19. 
    In a galvanic cell, what ensures the charges of each solution remain balanced?

  • circuit
  • salt bridge
  • cathode
  • anode

  • 20. 
    From the list below, which step comes last when you are balancing half-equations?

  • Add H2O to balance oxygen
  • Balance elements other that O and H
  • Balance the charge with e-
  • Add H+ to balance hydrogen

  • 21. 
    Oxidation is....

  • Gain of electrons
  • Loss of electrons
  • Both the loss and gain of electrons
  • None of these

  • 22. 
    Determine the oxidation number of chromium in CrO42-.

  • 5
  • 6
  • 4
  • 2

  • 23. 
    What is the oxidation number assigned to manganese in KMnO4?

  • 7
  • 5
  • 4
  • 0

  • 24. 
    Which of the following elements is used as the standard electrode?

  • Chlorine
  • Aluminium
  • Hydrogen
  • Lithium

  • 25. 
    Substance that oxidizes another substance by accepting its electrons.

  • oxidising agent
  • reducing agent
  • combustion
  • None of these

  • 26. 
    What is the oxidation state of sulphur in SO42- (aq)?

  • 4
  • 6
  • 2
  • 0

  • 27. 
    A decrease in oxidation number.

  • Oxidation
  • combination
  • reduction
  • All of above

  • 28. 
    Which of the following elements will oxidize most easily?

  • Chlorine
  • Aluminium
  • Hydrogen
  • Lithium

  • 29. 
    Reduction is....

  • Gain of electrons
  • Loss of electrons
  • Both the loss and gain of electrons
  • None of these

  • 30. 
    What is the oxidation number of iodine in KIO3?

  • 5
  • 1
  • 0
  • -1
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