CHAPTER 11 : OXIDATION AND REACTION 1. Which of the following reactions occurs when molten lead(II) bromide is electrolysed by using carbon electrodes? A Redox reaction B Metal corrosion of reaction C Reduction of bromide ion at cathode D Oxidation of bromide ion at anode 2. Which of the following statements about reduction and oxidation is true? A Reduction is a process of adding oxygen B Oxidation is a process of losing electron C Reduction is a process where the oxidation number of a substance increases. D Oxidation is the process of adding hydrogen 3. Which of the following is reducing agent? A Zinc B Bromine water C Acidified sodium dichromate(VI) D Acidified potassium manganate(VII) acidified 4. Which of the following reactions can’t be carried out byusing electrolysis method? A Danielle Cell B Extraction of Aluminum C Decomposition of molten Lead(II)oxide D Recharging of Lead Acid Accumulator 5. The diagram shows the set up of the apparatus used to determine the position of hydrogen in reactivity series of metal. 1 Metal oxide Dry hidrogen gas Burning of excess hydrogen gas Heat
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
CHAPTER 11 : OXIDATION AND REACTION
1. Which of the following reactions occurs when molten lead(II) bromide is electrolysed by using carbon electrodes?
A Redox reactionB Metal corrosion of reactionC Reduction of bromide ion at cathodeD Oxidation of bromide ion at anode
2. Which of the following statements about reduction and oxidation is true?
A Reduction is a process of adding oxygenB Oxidation is a process of losing electronC Reduction is a process where the oxidation number of a substance
increases.D Oxidation is the process of adding hydrogen
4. Which of the following reactions can’t be carried out byusing electrolysis method?
A Danielle CellB Extraction of AluminumC Decomposition of molten Lead(II)oxideD Recharging of Lead Acid Accumulator
5. The diagram shows the set up of the apparatus used to determine the position of hydrogen in reactivity series of metal.
Which of the following metal oxide will be reduced by hydrogen?
I Zinc oxideII Iron(III) oxideIII Copper(II) oxide
1
Metal oxide
Dry hidrogen gas
Burning of excess hydrogen gas
Heat
IV Lead[II) oxide
A I and II onlyB II and III onlyC II and IV onlyD II, III and IV only
6. Which of the following metal is easily oxidized?
A ZincB LeadC AluminiumD Magnesium
7. Which of the following reactions do not involve redox reaction?
I DisplacementII PrecipitationIII CombustionIV Neutralisation
A I and II onlyB I and III onlyC II and III onlyD II and IV only
8. Which of the following is not a redox reaction?
A Rusting of ironB Neutralisation reactionC Reaction in nickel cadmium cellD Extraction of iro from their ore
9. Which of the following does not occur during extraction of silver using carbon?
A Carbon is oxidized to carbon dioxideB Tin(IV) oxide, SnO2 is reduced to tinC Tin(IV) oxide, SnO2 act as a reducing agentD The oxidation number of carbon increases from 0 to +4
10. The following are the advantages of using carbon in extraction of metals except
A carbon is easily availableB the cost for using carbon is cheaperC carbon is located under tin in the reactivity series of metalD the by product of the reaction which is carbon dioxide is easy to eliminate
2
Carbon is used as a reducing agent in the extraction of metals, like iron and tin from their ores.
11. Electrolysis is a process when a chemical substance is decomposed by using electricity. Which of the following statement is true in an electrolysis process?
A Anion receives electron at anodeB Cation receives electron at anodeC Cation receives electron at cathodeD Anion releases electron at cathode
12. The diagram shows the set-up of the apparatus to determine the location of carbon in the reactivity series of metals.
What is the observation at the end of experiment?
A The mixture remains unchangedB A brown solid is producedC Carbon reacts as an oxidising agentD Copper(II) oxide is oxidized to copper
13. What is the purpose of carbon in the displacement process of iron?
A To reduce iron oxide B To decrease the melting point of iron C To change iron ore to molten iron D To oxidized the impurity in iron ore
14. Metal X is located between iron and zinc in the metal reactivity series. Which of the following metals can reduce X oxide?
A Copper
B Tin C Lead D Aluminium
3
Mixture of carbon powder and copper(II) oxide powder
Pipe-clay triangle
Tripod stand
Asbestos paper
Heat
15. Nickel is located between iron and zinc in the metal reactivity series. Which of the following metal can reduce nickel oxide?
I Tin II Lead III Aluminium IV Magnesium
A I and II only B II and III only C III and IV only D I,II,III and IV
16. All of the following metals can react as a reducing agent. Which one is the strongest?
A Iron B Sodium C Silver D Aluminium
17. Aluminium is extracted from its ore by electrolysis process. Why is aluminium cannot be extracted from its ore by heating it with carbon?
A Impure aluminium is producedB The cost of extraction is very highC Aluminium is more reactive than carbonD Aluminium can react with carbon
18. Which of the following shows the arrangement of the metal reactivity series with oxygen in ascending order?
A K,Na,Mg,Al B Sn,Fe,Zn,Cl C Zn,Fe,Sn,Pb
D Cu,Hg,Ag,Au
19. What is the name of compound which its formula is NaClO4?
A Sodium chlorate(III)B Sodium(I) chlorate(I)C Sodium chlorate(VII)D Sodium(I) chlorate(VII)
20. Which of the following substances can oxidize iron(II), Fe2+ ion to Iron(II), Fe3+ ion ?
A Zinc metalB Dilute sulphuric acid, H2SO4
C Hidrogen sulphide gasD Acidicfied potassium manganate(VII) solution
4
21. The following is an ionic equation,
Which of the following is true about that equation?
A Y2+ is oxidised to YB X2+ is a reducing agentC X is an oxidising agentD X donates electron to Y2+
22. The diagram below shows the set up of the apparatus to change iron(III), Fe3+ ion to iron(II), Fe2+ ion.
Which of the following can replace zinc powder in this reaction?
23. The diagram shows the set-up of the apparatus of an experiment. The apparatus is left for an hour.
Which of the following statements is not true?
A Electron transferred from electrode P to electrode QB Potassium iodide solution turn to brown in colourC The orange colour of acidified potassium dichromate(VII) decolourisedD The oxidation number of chromium change from +6 to +3
25. The table shows some chemical changes occur in four chemical reactions.
Reactions Chemical changesWXYZ
Zinc atom changes to zinc ionMnO4ˉ changes to Mn2+
Iodide ion changes to iodineChlorine molecule changes to chloride ion
Among the chemical changes above, which one loses electron?
A W and XB W and YC X and YD Y and Z
26. The diagram shows the set up of the apparatus of an experiment to investigate the effect of corrosion to iron
Which of the following decrease the rate of rusting of iron?
A Ion Fe 2+ accept electron to form Fe B Metal X is less electropositive than iron C Metal X is more electropositive than iron D Sodium chloride solution is a strong electrolyte
6
Iron nail
Metal X
Sodium chloride solution
27. The diagram shows the reaction between hot lead powder with bromine gas.
Which of the following is correct ?
A White solid is producedB Lead atom oxidized to lead(II) ionC Oxidation number of Bromine decreases from 0 to -2D Bromine reacts as oxidising agent
28. When the mixture of lead(II) oxide and aluminium powder is heated, lead is produced as shown in the equation below.
This reaction occur because,
A lead is an amphoteric oxide B aluminium burns reactively C lead is a strong reducing agent
D aluminium is more reactive than lead
30. The following chemical equation shows a halogen replacement reaction.
Which of the following statement is true about the reaction?
A Bromine gas is a reducing agentB Bromide ion undergoes reduction C Iodide ion undergoes oxidationD Oxidation number of iodine changes from +1 to +2
7
Br2[g] + 2KI[aq] → I2[g] + 2KBr[aq]
3PbO + 2Al Al2O3 + 3Pb
Hot lead powder
Bromine gas
Gas jar spoon
31. In an experiment, concentrated sodium chloride solution is electrolised using carbon electrodes. Which of the following statement is true?
A Hidrogen,H+ ion is oxidizedB Chloride,Cl- ion acts as oxidizing agentC Sodium,Na+ ion undergoes oxidationD The oxidation number of hydrogen decreases from +1 to 0
32. The diagram shows a simple voltaic cell.
Which of the following, is reduced in that cell?
A CopperB Sodium ionC MagnesiumD Hidrogen ion
33. The diagram shows, a few drops of acidic potassium manganate(VII) solution are dropped into X solution.
If the purple colour of acidified potassium manganate(VII) is decolourised, X solution should be
A bromine water.B iron(II) ion solution.C iron(III) ion solution.D dichromate(VI) ionsolution.
8
Acidified potassium manganate(VII) solution
X solution
V
CopperMagnesium
Sodium sulphatesolution
34. The diagram shows chemical cell.
Which of the following, will happen in the cell?
A Magnesium rode becomes thinner.B The number of copper(II) ion increase.C Copper rode acts as a negative terminal.D Magnesium acts as an oxidation agent.
35. The equation below represents the displacement reaction between metal X, Y and Z.
Choose the correct statement for this reaction?
A Y is more electropositive than X B X and Z are oxidising agents C The arrangement of reactivity in descending order is Z ,X, Y D X2+ and Y2+ are reducing agents, where as Z2+ is an oxidising agent
36. The extraction of tin from its ore is a redox reaction. Which of the following Substances can be use to reduce tin(IV)oxide to tin?
A Carbon B Copper C Lead D Silver
37. Which of the following equations represents a redox reaction?
A HCl + KOH → KCl + H2O
B H2SO4 + Mg → MgSO4 + H2
C Pb(NO3)2 + K2CO3 → PbCO3 + 2KNO3
9
Copper(II) sulphate solution, 1.0 mol dm-3
Magnesium sulphate solution, 1.0 mol dm-3
Copper metalMagnesium metal
Reaction I : X (s) + Y2+ (aq) → X2+ (aq) + Y (s)Reaction II : Z(s) + X2+ (aq) → Z2+ (aq) + X(s)
D CaCO3 + 2HCl → CaCl2 + CO2 + H2
38. The rusting of iron can be reduced by coiling the iron with other metals.Which of the following metals can protect the iron from rusting?
A Zinc B Tin C Copper D Lead
39. Which of the following metals will increase in mass if heated in steam?
A CopperB MagnesiumC LeadD Silver
40. Reaction between acidified potassium dichromate,K2Cr2O7 with iron(II) sulphate,FeSO4 solution is a redox reaction. In this reaction, the oxidation number of chromium changes from
A +7 to +3B +6 to +3C +6 to +2D +5 to +1
41. Which of the following shows the correct oxidation number of manganese?
MnO MnO2 Mn2O3
A 2 4 6B 1 2 6C 1 2 3D 2 4 3
42.
Based on the above statement, which of the following metal can be used to protect tin from corrosion?
A ZincB CopperC LeadD Silver
43. The equation below, shows half equation for a redox reaction.
10
Corrosion of metal can be protected by using other metal
X2O72- + 14H+ + ne- → 2X3+ + 7H2O
From the equation, a X2O72- ion is reduced to two X3+ ion by receiving n
electrons, (ne-) as shown in the above half equation. What is the value of n?
A 2B 6C 8D 9
44. The equation shows a redox reaction.
In the reaction, what is the change in the oxidation number for nitrogen?
A -3 to 0B +3 to 0C +1 to -2D -2 to +2
45. When a piece of iron plated with X metal was scratched, the iron did not rust but when a piece of X metal plated with iron was scratched, the iron rusting very quickly. From the above observations, the arrangement of metals X, Y and iron in descending order in electrochemical series is
A Iron, X, YB X, iron, YC X, Y, ironD Y, iron X
46. The following equation shows a reaction between hydrogen and excess air.
In the reaction, the oxidation number of hydrogen changes from
A 0 to +1B 0 to +2C +2 to 0D +1 to +2
47. The chemical equation shows a redox reaction.
Which of the following is the changes of the oxidation number of nitrogen?
11
3CuO + 2NH3 → 3Cu + N2 + 3H2O
2H2 + O2 → 2H2O
2KNO3 → 2KNO2 + O2
∆
A +5 to +3B +6 to +4C +3 to +5D +4 to +6
48. Which of the following substances contains nitrogen with the highest oxidation number?
A N2O B KNO2
C HNO3
D NH4Cl
49. The equation below shows the reduction of iron(III) to iron(II) by Sn2+.What is the value of n in Snn+?
A 3B 4C 5D 6
50. Which of the following pair of substances, have the same oxidation number for the underlined elements?
A CrO42- and Cr2O7 2-
B KNO2 and NaNO3
C SO4 2- and SO32-
D KMnO4 and Mn2O3
STRUCTURED QUESTIONS
SECTION A
Answer all the questions
1. The diagram shows the set up of the apparatus to investigate transfer of
electrons at a distance between iron(II) sulphate solution and
12
2Fe 3+(aq) + Sn2+ (aq) 2 Fe2+(aq) + Sn n+(aq)
acidified potassium dichromate(VI) solution
The voltmeter shows reading. After a few minutes, solution at X side and Y side
If iron is exposed to water and air, it will undergo rusting process quickly. So, in arab countries, iron pipe that carries oil is tied with magnesium bag to control it from undergoing rusting process.
Refer to the above situation, plan a laboratory experiment to show that
magnesium can control rusting process on iron.
Your experiment planning should consist the following matter.