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WorksheetsRedox Reaction🤩
Total questions: 31
Worksheet time: 22mins
Define redox reaction.
(a)
Which of the following is oxidation reaction?
Gain hydrogen
Gain electron
Gain oxygen
Which of the following is reduction reaction?
Loss hydrogen
Loss electron
Loss oxygen
What is the oxidation number of sulphur in sulphuric acid?
🧮✏️
-2
-4
+4
+6
Find the oxidation number of copper in copper(II) oxide.
(a)
State the change in oxidation number of zinc in this reaction.
Mg + ZnSO4 —> MgSO4 + Zn
(a)
Which of the following is not redox reaction?
Copper reacts with silver nitrate solution
Hydrochloric acid reacts with ammonium hydroxide solution
Potassium iodide solution reacts with lead(II) nitrate solution
Carbon reacts with iron(II) oxide
Magnesium powder is added to iron(III) sulphate solution . Brown solution changes to green. Write half equation for reduction reaction.
(a)
Dichromate(VI) ions can be changed to chromium(III) ions by adding potassium dichromate(VI) solution to
Chlorine water
Hydrogen peroxide
Iron(II) sulphate solution
Iron(III) sulphate solution
2I- —> I2 + 2e
Based on the equation, which of the following is correct?
Electrons are donated by iodine
Electron are accepted by iodine
Electron are accepted by iodide ion
Electrons are donated by iodide ions
C + 2CuO —> 2Cu + CO2
Which of the following statement is correct about the reaction?
Copper(II) oxide undergoes reduction as the oxidation number of copper(II) ion decreases from +2 to 0 to form copper
Copper(II) oxide undergoes reduction reaction as the oxidation number of copper decreases from +2 to 0
When chlorine water is added to potassium bromide solution , redox reaction occurs. Which of the following are the correct ionic equation for oxidation and reduction reaction?
Cl2 —> 2Cl- + 2e
2Br- + 2e —> Br2
2Cl- + 2e —> Cl2
Br2 + 2e —> 2Br-
When chlorine water is added to potassium bromide solution , redox reaction occurs. Which of the following statement is correct to explain the oxidation or reduction reaction in terms of the change in oxidation number?
Chloride ions undergo oxidation as the oxidation number of chloride ion increase from -1 to 0 to form chlorine
Bromide ion undergoes oxidation as the oxidation number of bromide ions increases from -1 to 0 to form bromine
Chlorine undergoes reduction as the oxidation number of chlorine decreases from 0 to-1
Bromine undergoes reduction as the oxidation number of bromine decreases from 0 to -1 to for bromide ions
Diagram 14 shows the rusting process. What are the condition for rusting?
Oxygen
Water
Iron
Electrons
Which reaction occurs at anode?
Fe —> Fe2+ + 2e
O2 + 2H2O + 4e —> 4OH-
Rita & Lina (not the real name👩🔬👩🔬) added 2cm3 of bromine water into 2cm3 of sodium chloride solution as shown by image 16. What is the observation when the mixture is added with 1,1,1-trichloroethane?
Colorless solution change to pale yellow
Colorless solution change to purple
Brown solution remains brown
Image 17 shows the experiment to investigate the redox reaction based on the transfer of electrons at a distance by using acidified potassium manganante(VII) solution and potassium iodide solution.
name oxidizing agent.
(a)
Image 18 shows the experiment to investigate the redox reaction based on the transfer of electrons at a distance by using acidified potassium manganante(VII) solution and potassium iodide solution.
What is the ionic equation at the negative terminal?
(a)
Which of the following is not an oxidizing agent?
Iron(II) sulphate
Sulphur dioxide
Sulphuric acid
Hydrogen peroxide
Choose reducing agent📌
Carbon
Chlorine
Calcium
Hydrogen
Diagram 21 shows a blast furnace used to extract metals from its ore. Name a suitable metal that is suitable to be extracted by using this method.
Magnesium
Aluminum
Tin
Iron
Diagram 22 shows a blast furnace used to extract metal from its ore. Name the reducing agent for the reaction in blast furnace
(a)
Based on diagram 23, what is the function of copper(II) chloride solution
Salt bridge
Allow movement of ions between two electrolytes to complete the circuit.
Allow movement of electrons between two electrolytes to complete the circuit
Diagram 24 shows the apparatus set-up to investigate the redox reaction based on the transfer of electron. Which of the following statement is correct?
Electrons move from negative terminal to positive terminal through the solutions
Substance at the positive terminal releases electron
Oxidation occurs at the negative terminal
Diagram 25 shows the apparatus set-up for the electrolysis of 1.0 mol dm-3 of copper(II) chloride solution. Choose the correct ions discharge at anode and cathode .
Anode: OH- ion, Cathode: Cu2+ ion
Anode: Cl- ion, Cathode: Cu2+ ion
Anode: Cu2+ ion, Cathode: Cl- ion
Anode: Cu2+ ion, Cathode: OH- ion
Diagram 25 shows the apparatus set-up for the electrolysis of 1.0 mol dm-3 of copper(II) chloride solution.
Write the ionic equation for the oxidation reaction.
(a)
Diagram 27 shows apparatus set-up to investigate the effect of other metals on the rusting of iron.
Which test tube the highest intensity of blue spot?
II
III
IV
V
Diagram 27 shows apparatus set-up to investigate the effect of other metals on the rusting of iron.
Which test tube has NO blue spot?
II
III
IV
V
Diagram 27 shows apparatus set-up to investigate the effect of other metals on the rusting of iron.
What is the substance that undergoes oxidation reaction in test tube V
Tin
Iron
Water
Oxygen
Based on diagram 30, which metal can prevent iron from rusting ?
Magnesium
Copper
Zinc
Tin
Based on diagram 31, what are the ionic equation for the oxidation reaction in both test tubes?
IV: Zn —> Zn2+ + 2e
IV: Fe —> Fe2+ + 2e
III: Fe —> Fe2+ + 2e
III: Cu —> Cu2+ + 2e
