Question

_____ coating on silver is an example of corrosion.
1. Blue
2. Black
3. Green
4. Brown

Answer 1

Correct Answer - Option 2 : Black

The correct answer is ​Black.

• The black coating on silver is an example of corrosion.

• When a metal deteriorates due to its reaction with air present in the atmosphere, it can be said as corrosion.
• The process of corrosion takes place due to oxidation.
• Iron is rusted and silver is tarnished in the air when they are left free in the air.
• The metals need to be protected from corrosion.
• Rust is an iron oxide, a usually reddish-brown oxide formed by the reaction of iron and oxygen in the catalytic presence of water or air moisture.
• The beautiful blue-green color (patina) on copper after oxidation is the visible result of the metals losing electrons to the air.

• Many methods are developed via industrial research to protect a metal from corrosion.
• Except for gold and platinum, the corrosion of most of the metals is spontaneous.
• Anti-corrosive chemicals are used to prevent metal from corrosion.
• Iron can also be coated with tin to protect it from corrosion.
• Tin is less reactive and it will protect the iron.
• Cathodic protection, hot deep galvanization, alloyed steel, and barrier coatings are some other methods to protect a metal from corrosion.