Electrolysis

Definition

Electrolysis is a chemical process in which electrical energy is used to drive a non-spontaneous chemical reaction. It involves passing an electric current through an electrolyte, causing ions to move and resulting in the deposition of substances at the electrodes.

5 Must Know Facts For Your Next Test

1. Electrolysis requires an external power source to provide the necessary energy for the reaction.
2. The substance that undergoes electrolysis must be in a molten or aqueous state so that ions can move freely.
3. Electrodes play a crucial role: the anode attracts anions, and the cathode attracts cations.
4. Common applications include electroplating, electrorefining, and water splitting into hydrogen and oxygen.
5. Faraday's laws of electrolysis quantify the relationship between the amount of substance produced at each electrode and the quantity of electricity passed through the electrolyte.

Review Questions

• What is required for electrolysis to occur?
• Describe how ions move during electrolysis and their respective destinations at the electrodes.
• List two common applications of electrolysis.

Related terms

Anode:

The electrode where oxidation occurs during electrolysis; it attracts anions.

Cathode:

The electrode where reduction occurs during electrolysis; it attracts cations.

Faraday's Laws of Electrolysis:

Two laws that relate the amount of substance altered at each electrode to the quantity of electric charge passed through the electrolyte.