Electrodes

 Electrodes

Definition

Electrodes are conductive materials (usually metals or carbon) that allow electric current to enter or leave an electrolyte during electrolysis.

Explanation

In electrolysis, electrodes are placed in an electrolyte solution or molten salt. When a direct current flows through the circuit, ions in the solution move toward the electrodes. The positive electrode is the anode, and the negative electrode is the cathode.

At the electrodes, oxidation (loss of electrons) and reduction (gain of electrons) occur. These reactions result in the release or deposition of substances.

Key Points

• Electrodes conduct electricity into/out of the electrolyte

• Anode (+) attracts anions (negative ions) → oxidation

• Cathode (–) attracts cations (positive ions) → reduction

• Can be inert (graphite, platinum) or reactive (copper, silver)

• Essential for redox reactions in electrolysis

Types of Electrodes

 1. Inert Electrodes – Do not react (e.g., platinum, graphite)

 2. Active Electrodes – Take part in the reaction (e.g., copper, zinc)

Examples

• Copper anode dissolving during copper refining

• Graphite electrodes producing hydrogen and oxygen from water

• Silver cathode receiving silver ions in electroplating

Applications / Relevance

• ⚡ Electrolysis of water, salts, and acids

• 🔋 Batteries and fuel cells

• ⚗️ Electroplating and metal refining

• 💍 Jewellery coating and industrial finishing

Question

What happens at the cathode during electrolysis?

Answer:

Positive ions (cations) gain electrons (reduction) and get deposited at the cathode.