EASE 2 preparation past paper Electrolysis

In electrolysis, ions that get reduced on the cathode are metal ions outside group 1, group 2 and group 3.

Whereas ions that get oxidised on the anode are either halogen ions or hydroxide ions. The electrolysis of copper(II) sulfate happens according to this reaction.

2CuSO₄ + 2OH^- → O₂ + 2Cu + 2H₂SO₄

Which reactions happen on the surface of the cathode?

• 2OH^- → O₂ + 2H⁺ + 4e^-

• Cu²⁺ + 2e^- → Cu

• 2H⁺ + 2e^- → H₂

• H₂O + 2e^- → H₂ + O^2-

The diagram shows the electrolysis of molten zinc chloride, ZnCl₂.

Which statement is correct?

• Oxidation occurs at electrode X and the equation is:

  2Cl^- → Cl₂ + 2e^-

• Oxidation occurs at electrode Y and the equation is:

  Zn²⁺ + 2e^- → Zn

• Reduction occurs at electrode X and the equation is:

  Zn²⁺ + 2e^- → Zn

• Reduction occurs at electrode Y and the equation is:

  2Cl^- → Cl₂ + 2e^-

When concentrated sodium chloride solution is electrolysed, element X and Y are formed.

What are X and Y?

• A

• B

• C

• D

Which of the following statements correctly explain the advantages of hydrogen-oxygen fuel cells?

1) It does not emit carbon dioxide as a result of combustion reaction

2) It has a lower flammability than petrol

3) It is economically cheap

• 1 only

• 1 and 2 only

• 2 and 3 only

• 1, 2 and 3

In a fuel cell ..1.. energy is converted to ..2.. energy.

• A

• B

• C

• D

Please take a look at this figure of a simple electrolytic cell :

Which one of the following options describe the node, the name and the function of electrolytic components correctly?

• 1, 2 and 3

• 1 and 3

• 2 and 4

• 4 only

Electricity is passed separately through concentrated hydrochloric acid, concentrated aqueous sodium chloride and dilute sulfuric acid. In which rows are the electrolysis products correctly named?

• 1, 2 and 3

• 1 and 3

• 2 and 4

• 4 only

Molten lead(II) bromide is electrolysed as shown.

What are being produced at the anode and cathode?

• A

• B

• C

• D

The diagram shows the electrolysis of copper(II) sulfate solution.

a) Write the reaction occurs in cathode.

b) Write the reaction occurs in anode.

The diagram shows the electrolysis of molten lithium bromide.

(i) Describe how the direction of the electron flow?

(ii) Write an ionic equation for the reaction at the negative electrode (cathode)!

(iii) Write an ionic equation for the reaction at the positive electrode (anode)!