Tin cans, used for storing food, are made by electroplating tin on which of the following metal?

Iron

The correct answer is option 4. Iron.

Tin cans used for storing food are typically made by a process known as electroplating, where a layer of tin is deposited onto the surface of another metal, providing protection against corrosion and making the container suitable for food storage. In this case, the metal that is electroplated with tin is iron. Here's how the process works:

1. Surface Preparation:

The iron sheets or containers are cleaned thoroughly to remove any contaminants or impurities from their surface.

2. Electroplating Bath:

The cleaned iron containers are immersed in an electroplating bath that contains a solution of tin salts. The bath typically consists of tin chloride or tin sulfate dissolved in water.

3. Electroplating Process:

The iron containers are connected to the negative terminal (cathode) of the power supply, and a piece of tin serves as the anode (positive terminal).

When an electric current is applied, tin ions in the solution are reduced at the surface of the iron containers, forming a thin layer of solid tin.

4. Formation of Tin Coating:

As the electroplating process progresses, tin atoms are deposited onto the iron surface, forming a uniform and adherent layer.

5. Benefits of Tin Coating:

The tin coating serves as a barrier, protecting the iron from corrosion and oxidation.

Tin is corrosion-resistant, and it helps to prevent the iron from reacting with the contents of the food cans.

6. Food Safety:

Tin is a food-safe material, and the electroplating process ensures that the tin layer is firmly bonded to the iron, preventing it from leaching into the stored food.

7. Common Applications:

Electroplated tin coatings are commonly used in the production of food cans, beverage cans, and various other containers where corrosion resistance and food safety are essential.

In summary, electroplating tin onto iron provides an effective and economical method for producing food cans with corrosion-resistant properties, ensuring the safety and longevity of the stored food products.