Electrolytic Processes Practice Questions

Which row shows the products formed at the anode and at the cathode when molten lead bromide is electrolysed?

Put a cross ( ☒ ) in the box next to your answer.

Option	product at anode	product at cathode
A	bromine	hydrogen
B	oxygen	lead
C	bromine	lead
D	hydrogen	bromine

Solid lead bromide does not conduct electricity, but molten lead bromide does.

Explain why.

Which of the following describes electrolysis?

Put a cross ( ☒ ) in the box next to your answer.

☐ A electrical energy from a direct current supply decomposes an electrolyte

☐ B heat energy from a Bunsen burner decomposes an electrolyte

☐ C electrical energy from an alternating current supply joins ions together

☐ D electrons move through an electrolyte from the anode to the cathode

During electrolysis, negatively charged ions move towards one of the electrodes.

Name this electrode.

Name the product formed at the cathode.

A gas is given off at the anode.

Name this gas and describe a test to show that this gas is produced.

Before the electrolysis, the student rubs both copper electrodes with emery paper.

Explain why the student does this.

At the end of the electrolysis, the student needs to find the mass of copper deposited on the cathode.

Describe how the student should do this.

Write the half equation for the reaction at the cathode.

Write the half equation for the reaction at the anode.

State at which electrode oxidation takes place and explain your answer in terms of electrons.

Name the gas formed at the cathode and explain, in terms of electrons, how it is formed.

Name the product formed at the anode.

Name the compound that remains in the solution at the end of the electrolysis.

Solid silver nitrate does not conduct electricity, but silver nitrate solution is an electrolyte.

Explain why.

Silver chloride is shaken with water and electrodes are placed in the mixture. No current flows.

Explain why.

Describe, using the data in the table, what the results show about the volumes of the two gases produced in this experiment.

The gas collected at the positive electrode is oxygen.

Describe the test and result that shows the gas is oxygen.

Explain why sodium sulfate is dissolved in the water before the electrolysis is carried out.

Explain, in terms of ions and electrons, what happens at each electrode and what happens to the solution during this electrolysis.

In your answer, explain how this process is used in industry to purify copper.

Calculate the decrease in mass of the anode and the increase in mass of the cathode.

Suggest why the increase in mass of the cathode is less than the decrease in mass of the anode.

Explain, using half equations, how this process produces pure copper at the cathode.

Write the balanced half equation for the formation of oxygen at the anode.

The half equation for the reaction at the cathode is $\mathrm{2H^+ + 2e^- \rightarrow H_2}$.

Use the two half equations to explain why the volume of hydrogen collected is twice the volume of oxygen collected.