Electrolysis

What is the name of the positive electrode?

• cathode
• anode

What is the name of the negative electrode?

• cathode
• anode

What is the product formed at the anode during the electrolysis of concentrated copper(II) chloride?

• copper
• chlorine
• hydrogen
• oxygen

What is the gas produced at the anode during the electrolysis of very dilute hydrochloric acid?

• water

• oxygen

• hydrogen

• chlorine

Positive ions (cations) move towards the cathode (-) where they will discharge by....

• Breaking apart

• Losing electrons

• Clumping together.

• Gaining electrons

Choose the half-equation that shows the discharge of aluminium ion.

• Al³⁺ - 3e^- --> Al

• Al²⁺ + 3e^- --> Al

• Al³⁺ + 3e^- --> Al

• Al³⁺ --> Al + 3e^-

What is the half-equation for the discharge of hydroxide ions?

• 2O^2- --> O₂ + 4e^-

• OH^- --> OH + e

• 4OH^- --> 2H₂O + O₂ + 4e^-

• 2H₂O + O₂ + 4e^- --> 4OH^-

Electroplating is an industrial process where objects are coated by a thin layer of a nonreactive metal by electrolysis. What should be used as the cathode in this process?

• Graphite electrode

• The electroplating metal

• The object to be electroplated

• Magnesium ribbon

If the fork is to be electroplated with silver metal, what electrolyte should be used?

• Molten silver chloride

• Aqueous silver nitrate

• Sodium chloride solution

• Copper(II) sulphate solution

The picture shows electrolysis of copper(II) sulphate solution using graphite electrodes. Besides formation of brown solid on the cathode, what other observations can be made?

• The mass of graphite anode decreases.

• The blue colour solution becomes paler.

• Bubbles of gas form at the anode.

• The blue colour solution becomes darker.