What Is Electroplating?

Electroplating is the process of coating a metal object with a thin layer of another metal using electrolysis.

This technique is widely used in industry to improve the appearance, durability, and corrosion resistance of metals.

During electroplating, an electric current is passed through a solution containing metal ions, causing the metal to deposit onto the surface of another object.

Why Electroplating Is Used

Electroplating has many important uses.

It is commonly used to:

• Protect metals from corrosion
• Improve the appearance of metal objects
• Increase durability and resistance to wear
• Reduce the cost of expensive metals

For example, inexpensive metals may be coated with a thin layer of gold or silver to make them look more attractive.

How Electroplating Works

Electroplating uses the same principles as electrolysis.

An electroplating setup usually includes:

• An electrolyte solution containing metal ions
• A metal object to be coated (cathode)
• A metal plate of the coating metal (anode)
• A power supply

Electric current causes metal ions to move and deposit onto the object.

Electroplating Process

Cathode (Negative Electrode)

The object that needs to be plated is connected to the negative terminal.

At the cathode:

• Metal ions gain electrons
• Metal atoms deposit onto the object

Example:

Cu²⁺ + 2e⁻ → Cu

Copper metal coats the object.

Anode (Positive Electrode)

The plating metal is connected to the positive terminal.

At the anode:

• Metal atoms lose electrons
• Metal ions enter the solution

Example:

Cu → Cu²⁺ + 2e⁻

This keeps the concentration of metal ions in the electrolyte stable.

Example – Copper Electroplating

In copper electroplating:

Electrolyte → Copper(II) sulfate solution

Cathode → Metal object being coated

Anode → Copper plate

During electrolysis:

• Copper ions deposit on the object
• Copper atoms from the anode dissolve into the solution

This gradually coats the object with a thin copper layer.

Examples of Electroplated Products

Electroplating is used in many everyday products.

Examples include:

• Chrome-plated car parts
• Gold-plated jewellery
• Silver-plated cutlery
• Tin-plated food cans

These coatings improve both appearance and durability.

Advantages of Electroplating

Electroplating offers several benefits:

• Protects metals from rust and corrosion
• Enhances appearance and shine
• Allows use of less expensive base metals
• Improves wear resistance

Because of these advantages, electroplating is widely used in manufacturing and electronics.

Exam Tip (5070)

Students are commonly asked to:

• Define electroplating
• Identify the anode and cathode
• Explain how metal ions are deposited during electrolysis

Example exam question:

Why is electroplating used on metal objects?

Answer:

Electroplating is used to protect metals from corrosion and improve their appearance.

Practice Question

In electroplating, which electrode is the object being coated?

Answer

The object being coated is the cathode (negative electrode).

Metal ions gain electrons at the cathode and form a metal coating.

Study O Level Chemistry with IVY Online

Preparing for Cambridge O Level Chemistry (5070) becomes easier with clear explanations and exam-focused practice.

With the IVY Online App, students can access:

✔ Complete syllabus coverage
✔ Interactive concept explanations
✔ Topic-wise past paper questions
✔ Exam-focused revision

📱 Download the IVY Online App and start preparing smarter for Chemistry exams.