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    Electrolysis Problems

    Uploaded by

    Maku Michael
    This document provides information on electrolysis and electrochemical cells through a series of questions and diagrams. It defines key terms like electrolytes, electrolysis, anode, and cathode. It describes experiments involving electrolysis of various solutions like copper(II) chloride and copper(II) sulfate using different electrode materials. Observations are stated for what occurs at the anode and cathode. Equations are provided for electrode reactions and overall cell reactions. Applications of electrolysis and electrochemical cells are discussed such as metal plating and refining, and the industrial production of chemicals like sodium hydroxide. Factors that determine products of electrolysis and differences between electrolytes and electrodes are also covered.

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    © All Rights Reserved
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    Electrolysis Problems

    Uploaded by

    Maku Michael
    61 views8 pages
    This document provides information on electrolysis and electrochemical cells through a series of questions and diagrams. It defines key terms like electrolytes, electrolysis, anode, and cathode. It describes experiments involving electrolysis of various solutions like copper(II) chloride and copper(II) sulfate using different electrode materials. Observations are stated for what occurs at the anode and cathode. Equations are provided for electrode reactions and overall cell reactions. Applications of electrolysis and electrochemical cells are discussed such as metal plating and refining, and the industrial production of chemicals like sodium hydroxide. Factors that determine products of electrolysis and differences between electrolytes and electrodes are also covered.

    Original Description:

    Original Title

    14. ELECTROLYSIS PROBLEMS

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    This document provides information on electrolysis and electrochemical cells through a series of questions and diagrams. It defines key terms like electrolytes, electrolysis, anode, and cathode. It describes experiments involving electrolysis of various solutions like copper(II) chloride and copper(II) sulfate using different electrode materials. Observations are stated for what occurs at the anode and cathode. Equations are provided for electrode reactions and overall cell reactions. Applications of electrolysis and electrochemical cells are discussed such as metal plating and refining, and the industrial production of chemicals like sodium hydroxide. Factors that determine products of electrolysis and differences between electrolytes and electrodes are also covered.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    61 views8 pages

    Electrolysis Problems

    Uploaded by

    Maku Michael
    This document provides information on electrolysis and electrochemical cells through a series of questions and diagrams. It defines key terms like electrolytes, electrolysis, anode, and cathode. It describes experiments involving electrolysis of various solutions like copper(II) chloride and copper(II) sulfate using different electrode materials. Observations are stated for what occurs at the anode and cathode. Equations are provided for electrode reactions and overall cell reactions. Applications of electrolysis and electrochemical cells are discussed such as metal plating and refining, and the industrial production of chemicals like sodium hydroxide. Factors that determine products of electrolysis and differences between electrolytes and electrodes are also covered.

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    © All Rights Reserved
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    of 8

    ORDINARY LEVEL CHEMISTRY PROBLEMS

    TOPIC: ELECTROLYSIS AND ELECTROCHEMICAL CELLS


    1. (a) Define the terms
    (i) Electrolytes
    (ii) Electrolysis
    (iii) Anode
    (iv) Cathode
    (b) state three factors which determine the discharge of ions at the electrodes.
    (c) Dilute copper(II) chloride solution was electrolysed using carbon electrode
    (i) state the ions present in solution.
    (ii) State what was observed at the anode and cathode
    (iii) Write the equation of reaction at each electrode.
    (d) State three applications of electrolysis.

    2. Figure 1 shows an electrochemical cell.

    (a) State what is observed at the copper foil.


    (b) Write the equation(s) for the reaction at the
    (i) Cathode
    (ii) Anode
    (c) Write the overall cell reaction equation
    (d) State one application of an electrochemical cell.
    3. (a) Differentiate between the terms anode and cathode
    (b) Figure below shows a simple Daniel cell.
    Which rod is acting as the;
    (i) Cathode:
    (ii) Anode
    (c) (i) Name the electrolyte W:
    (ii) State the role of the salt bridge in the cell
    (d) Write the equation for the overall cell reaction
    4. The circuit below was used to study the effect of electricity on lead(II) bromide

    (a) State was observed


    (i) Before lead(II) bromide melted
    (ii) After lead(II) bromide had completely melted
    (b) Explain your answer in (a)
    (c) Write equation for the reaction that took place at
    (i) Terminal P
    (ii) Terminal Q
    5. Copper(II) sulphate solution was electrolysed using carbon electrodes
    (a) State what was observed at the
    (i) Anode
    (ii) Cathode
    (b) Write equations for the reaction at the
    (i) Anode
    (ii) Cathode
    (c) Explain your observation at the cathode
    6. (a) Draw a diagram of a cell consisting of a zinc rod dipped in zinc sulphate and a copper
    rod dipped in copper(II) sulphate solution, with the solutions separated by a porous
    wall and the rods connected by a wire
    (b) Indicate the
    (i) Charges on each electrode
    (ii) Direction of electron movement in the wire
    (c) Write
    (i) Equations for the reaction at each electrode
    (ii) An equation for the overall reaction
    7. Figure below shows a simple cell

    (a) Write equations for the reactions taking place at the


    (i) Anode
    (ii) Cathode
    (b) Write the overall equation for the reaction
    (c) Draw an arrow on the diagram to show the flow of electrons
    (d) Identify substances X, Y and Z
    8. The diagram below shows the arrangement of the apparatus used for purification of
    copper.
    (a) Name the substance used as the
    (i) Anode

    (ii) Cathode
    (b) Name the electrolyte
    (c) Write equation for the reaction taking place at the
    (i) Anode
    (ii) Cathode
    (d) State what would be observed during the experiment
    9. The diagram below is of electrolytic cell of the electrolysis of dilute sulphuric acid

    (a) Name the gases X and Y


    (b) Write equation for the reaction taking place at the terminals
    (c) State two industrial applications of electrolysis
    (d) Describe the industrial manufacture of sodium hydroxide
    (e) Draw a diagram for the electrolysis of copper(II) sulphate using copper electrodes
    (f) Write equations for the reactions taking place at the terminals
    (g) What is the application of the above cell drawn?
    10. Dilute copper(II) sulphate solution was electrolysed using carbon electrodes.
    (a) State what was observed at the
    (i) Anode
    (ii) Cathode
    (b) Write equations for the reactions at the
    (i) Anode
    (ii) Cathode
    (c) State what is observed at the anode and cathode when dilute copper(II) sulphate is
    electrolysed using copper electrodes
    11. Acidified water was electrolysed using platinum electrodes
    (a) Write an equation for the reaction that took place at the
    (i) Anode
    (ii) Cathode
    (b) Name one other substance that can be used as electrodes in the electrolysis of
    acidified water
    12. (a) (i) Using examples, state the differences between an electrode and an electrolyte
    (ii) Explain why aqueous solution of sodium chloride conducts electricity while solid
    sodium chloride does not
    (b) The diagram below shows a setup of an electrochemical cell which can be used to
    compare the reactivity of zinc and copper.
    (i) Identify the rod that is positively charged
    (ii) Identify the R and state its purpose
    (iii) Write equations for the reactions taking place at the copper and zinc rods
    (iv) Write equation for the overall reaction in the cell
    (v) State what would happen if zinc metal is dropped in a solution containing
    copper(II) ions
    13. (a) An aqueous solution of copper(II) sulphate was electrolysed between graphite
    electrodes
    (i) State what was observed at the anode and cathode
    (ii) Write equation for the reaction that takes place at each electrode
    (b) The solution that remained after electrolysis was tested with litmus solution
    (i) State what was observed
    (ii) Give a reason for your answer
    (c) If the electrolysis was repeated using copper terminals, what would be observed at the
    electrodes?
    (d) Describe how sodium hydroxide is manufactured by electrolysis of brine

    14. (a) State two factors that can determine the product formed at an electrode during
    electrolysis
    (b) Explain why aqueous solution of copper(II) chloride conducts electricity while solid
    copper(II) chloride does not
    (c) A dilute solution of copper(II) chloride was electrolysed using graphite electrodes
    (i) State what was observed at the cathode and write equation for the reaction that
    took place
    (ii) Name the substance that was produced at the anode
    (iii) Explain how the product at the anode is formed and write an equation to
    illustrate your answer.
    (d) Electrolysis of copper(II) chloride was repeated using copper electrodes. State what
    was observed at the anode and briefly explain your answer.

    15. Figure below shows the setup of the apparatus in which electric current was produced by
    dipping metals A and B in dilute sulphuric acid.

    (a) Name one metal that can be used as


    (i) A
    (ii) B
    (b) State which of the metals A and B is the
    (i) Anode
    (ii) Cathode
    (c) Both A and B are divalent metals. Write equation for the reaction at
    (i) The anode
    (ii) The cathode

    16. An aqueous solution of potassium iodide was electrolysed between carbon electrodes.
    (a) State what was observed at the anode
    (b) Name the product at the anode
    (c) Describe a test that can be carried out identify the product at the cathode
    (d) Litmus paper was dropped into the solution around the cathode at the end of the
    experiment
    (i) State what was observed
    (ii) Give a reason for your answer

    17. In order to illustrate a redox reaction, zinc was added to copper(II) sulphate solution and
    the setup left to stand for some time
    (a) State what was observed
    (b) State the substance that was
    (i) Oxidised
    (ii) Reduced
    (c) Write equation for the redox reaction that took place
    (d) Name one other substance that would react with copper(II) sulphate in a similar
    way as zinc

    18. Both copper wire and copper(II) sulphate conduct electricity.


    (a) Name the particles which conduct electricity in
    (i) Copper wire
    (ii) Aqueous copper(II) sulphate
    (b) The setup of apparatus in the diagram below was used to find out what happens
    when an electrolyte was connected to a source of electric current
    State what was observed
    (i) When the switch was closed
    (ii) If copper(II) sulphate crystal was replaced with potassium
    manganate(VII)crystal and the switch closed once again.
    (c) (i) Give a reason for the observation you have made in b(i) and (ii)
    (ii) State any general conclusion that can be drawn following the reason
    you have given in c(i)
    (d) Give the applications of electrolysis

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