1. An oxidation reaction is a process that involves the
A loss of oxygen
B gain of electrons
C loss of electrons
D gain of hydrogen
2. What is a redox reaction?
A A reduction reaction
B An oxidation reaction
C Both oxidation and reduction reaction
3. An oxidizing agent is a substance that
A donates oxygen
B accepts electrons
C donates electrons
D donates hydrogen
4. Which of the following is a half-equation?
A Cu2+ → Cu
B Cu2+ + 2e → Cu
C Zn + Cu2+ → Zn2+ + Cu
D Zn + CuCl2 → ZnCl2 + Cu
5. What is metal corrosion?
A Change of metal to its ion
B Change of ion to its metal atom
6. Which of the following substances is a reducing agent?
A Zinc
B Chlorine
C Potassium dichromate(VI)
D Potassium manganate(VII)
7. Which of the following is the most electropositive metal?
A Cu
B Mg
C Na
D Zn
8. Which of the following substances cannot be reduced by carbon, C?
A Zinc oxide, ZnO
B Iron(III) oxide, Fe2O3
C Copper(II) oxide, CuO
D Aluminium oxide, Al2O3
9. Which of the following cells can be recharged?
A Dry cell
B Alkaline cell
C Mercury cell
D Nickel-cadmium cell
10. Which of the following methods is not used in rust prevention?
A Making iron into alloys
B Galvanizing iron with zinc
C Attaching iron with copper
D Electroplating iron with silver
11. What is the oxidation number for iron in iron(II) chloride?
A +1
B +2
C +3
D +4
12. Which of the following is a redox reaction?
A Na2O + H2O → 2NaOH
B NaOH + HCl → NaCl + H2O
C 2Na + 2H2O → 2NaOH + H2
D NaCl + AgNO3 → AgCl + NaNO3
13. Which of the following undergoes oxidation reaction?
A Zn changes to Zn2+ ion
B MnO4- ion changes to Mn2+ ion
C Cr2O72- ion changes to Cr3+ ion
D Br2 molecule changes to Br- ion
14. The equation shows a displacement reaction.
Zn + Cu2+ → Zn2+ + Cu
Which of the following acts as a reducing agent?
A Cu
B Zn
C Cu2+
D Zn2+
15. The equation shows a redox reaction,
Cl2 + H2S → S + 2HCl
What is the change in the oxidation number for sulphur?
A +2 → 0
B -2 → 0
C +2 → -1
D -2 → -1
16. The ionic equation shows the displacement of bromine by chlorine.
Cl2 + 2Br- → 2Cl- + Br2
Which of the following is true?
A Chlorine is oxidized
B Chlorine is a reducing agent
C Bromide ion donates electron
D Bromide ion is an oxidizing agent
17. The equation shows the conversion of iron(III) ion into iron(II) ion.
2Fe3+ + Zn → 2Fe2+ + Zn2+
Which of the following substances can be used to replace zinc, Zn?
A KI
B Cl2
C KMnO4/H+
D K2Cr2O7/H+
18. The figure shows the set-up of apparatus to investigate the reactions between bromine and iron(II) sulphate solution.
What can be observe after a few minutes?
A Grey solid is formed
B Bromine water changes from colourless to brown
C Iron (II) sulphate solution changes from green to yellow.
D ron (II) sulphate solution changes from yellow to colourless
19. The figure shows the set-up of the apparatus used to study the transfer of electron at a distance.
What is substance P?
A Iodine solution
B Iron(II) chloride solution
C Iron(II) sulphate solution
D Potassium manganate(VII) solution
20. Which of the following mixtures can react when they are heated strongly?
A Carbon and zinc oxide
B Copper and iron oxide
C Copper and lead oxide
D Carbon and magnesium oxide
21. What is the oxidation number of chromium, Cr in Cr2O72- ?
A +2
B +3
C +6
D +7
22. Which of the following represents the oxidation number of nitrogen in the various oxides of nitrogen?
| | NO | NO2 | N2O4 |
| A | +1 | +2 | +2 |
| B | +1 | +1 | +2 |
| C | +2 | +4 | +4 |
| D | +2 | +4 | +8 |
23. The equation shows a redox reaction.
2X + Y 2+ → 2X + + Y
Based on the equation, which of the following is true?
A The oxidation number of X change from 0 to +1.
B The oxidation number of X changes from 0 to +2.
C The oxidation number of Y changes from +1 to 0.
D The oxidation number of X and Y does not change.
24. The half-equation shows an oxidation reaction.
Based on the equation, what is meant by oxidation reaction?
A Electrons are donated by iodine.
B Electrons are received by iodine.
C Electrons are donated by iodide ions.
D Electrons are received by iodide ions.
25. The ionic equation shows a redox reaction.
P (s) + Q2+(aq) P2+ (aq) + Q (s)
Which of the following statement is true?
A Q2+ is oxidized.
B P donates electrons
C P is an oxidizing agent
D Q2+ is a reducing agent
26. The figure shows the set-up of the apparatus for the electrolysis of copper(II) chloride solution.
After one hour, it is found that the intensity of the blue solution decreases.
Which of the following explains the observation?
A Cl− ion is discharged at the anode
B OH− ion is discharged at the anode
C H+ ion is discharged at the cathode
D Cu2+ ion is discharged at the cathode
27. The figure shows a chemical cell.
The reaction that occurs is given by the equation:
Zn (s) + CuSO4 (aq) ZnSO4 (aq) + Cu (s)
Which of the following is correct about the cell?
A Hydrogen gas is produced.
B Zinc is oxidized to zinc ion, Zn2+.
C Copper is oxidized to copper(II) ion, Cu2+.
D Electrons flow from the copper plate to the zinc plate.
28. The table shows two displacement reactions involving metals X, Y and Z.
| Reaction I |
|
| Reaction II |
|
What is the decreasing order of electropositive for metals X, Y and Z in the electrochemical series?
A X,Y,Z
B X,Z,Y
C Y,X,Z
D Z,X,Y
29. The figure shows an experiment to study the effect of different metals in contact with iron nail on rusting.
After one week, blue spots are seen in test tube B but not in test tube A.
What inference can you make from the observation?
A Iron(II) ions are formed in test tube A.
B Corrosion of iron occurs in test tube A .
C Zinc prevents the iron nail from rusting.
D Copper prevents the iron nail from rusting.
30. The table below shows the observation when the mixture of metal and oxide metal are heated strongly.
| Mixture | Observation |
| Metal Q + oxide P | Glows brightly |
| Metal R + oxide P | No changes |
Based on the observation, which of the following is the correct order of reactivity for the metal of P, Q, and R in the increasing order?
A P, Q, R
B Q, P, R
C R, P, Q
D R, Q, P
31. The equation shows the conversion of Fe2+ to Fe3+.
Fe2+ → Fe3+ + e
Explain why Fe2+ is oxidized.
……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………..
32. The equation shows a redox reaction.
Cu + 2Ag+ → Cu2+ + 2Ag
Explain why Cu acts as an oxidizing agent.
………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………
33. The figure shows the set-up of apparatus to investigate the effect of metal on rusting.
The results of the experiments are shown in the table.
| Set | Metal attached to iron nail | Observation |
| I | Magnesium | No blue colour formed |
| II | Copper | Blue colour formed |
Explain the difference in observations for both sets of experiments.
………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………
34. Study the two chemical equations.
Equation I : Na2SO4 + Ba(NO3)2 → BaSO4 + 2NaNO3
Equation II : Mg + CuSO4 → MgSO4 + Cu
From the equations, choose one that is a redox reaction and explain your answer.
Equation : ……………………………………………………………………………………….
Explanation : ……………………………………………………………………………………
…………………………………………………………………………………….
35. The figure shows two electrochemical cells.
(a) State the difference in the energy change in the two electrochemical cells.
………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………
(b) State the different products formed at the positive terminals in both cells.
………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………
Listen carefully to the text read by the teacher. Answer questions 36 and 37.
36. Which of the following statement is true?
A Bromide ion is a reducing agent.
B Oxidation process occurs at cathode
C Positively-charged lead(II) ions move to anode.
D lead (II) ions lose electrons to become metallic lead.
37. Which of the following substances is an oxidizing agent?
A Lead metal.
B Bromine gas.
C Lead (II) ions.
D Bromide ions.
Listen carefully to the text read by the teacher. Answer questions 38 and 39.
38. Which of the following statement is true?
A Bromine is an oxidizing agent.
B Bromine molecules are oxidized.
C The colourless bromine water turns brown.
D Bromine is less electronegative than iodine.
39. Which of the following substances undergoes oxidation?
A Iodine.
B Bromine.
C Iodide ion.
D Bromide ion.
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