Reactivity Series and Extraction of Metals - Corrosion and its Prevention

Question 1

What is corrosion?

Answer 1

Corrosion is the destruction of materials by chemical reactions with substances in the environment. Rusting is an example of corrosion.

Question 2

What is required for iron to rust

Answer 2

air and water

Question 3

How can corrosion be prevented

Answer 3

By applying a coat that acts as a barrier, such as greasing, painting or electroplating

Question 4

How is aluminium protected from corrosion

Answer 4

Aluminium has an oxide coating that protects the metal from further corrosion

Question 5

How else can you coat a metal to protect it from rusting

Answer 5

Some coatings contain more reactive metals to provide sacrificial protection e.g it reacts before the protected metal

Question 6

describe an experiment to show both air and water are necessary for rusting

Answer 6

1) put an iron nail in a boiling tube with just water, it wont rust
2) Put an iron nail in a boiling tube with just air, it wont rust
3) Put an iron nail in a boiling tube with air and water, it will rust