Electrochemistry-4

Question 1

Corrosion

Answer 1

• Corrosion slowly coats the surfaces of metallic objects with oxides or
  other salts of the metal.
• In corrosion, a metal is oxidised by loss of electrons
  to oxygen and formation of oxides.

Question 2

Examples of corrosion

Answer 2

The rusting of iron, tarnishing of silver,
development of green coating on copper and bronze are some of the
examples of corrosion

Question 3

Prevention of corrosion is of prime importance.

Answer 3

It not only saves
money but also helps in preventing accidents such as a bridge collapse
or failure of a key component due to corrosion.

• This can be done by covering
  the surface with paint or by some chemicals (e.g. bisphenol).
• cover the surface by other metals (Sn, Zn, etc.)
• An electrochemical method is to
  provide a sacrificial electrode of another metal (like Mg, Zn, etc.) which
  corrodes itself but saves the object.