Question

For prevention of corrosion of iron by cathodic protection:

• A. Iron is converted into cathodic site.
• B. Iron is converted into anodic site.
• C. Iron is brought in contact with a metal that is more easily reduced.
• D. Iron is brought in contact with a metal that is more easily oxidised.

Answer 1

Answer: (A), (D)

Iron is brought in contact with a metal that is more easily oxidised.

Cathodic protection: A technique to control corrosion of a metal surface by making it work as a cathode of an electrochemical cell by placing in contact with the metal that is more easily oxidised (like zinc)


Anode reaction:
$Zn\left(s\right)\rightleftharpoons Z{n}^{2+}\left(aq\right)+2e^{-}$
Cathode reaction:
$O_2\left(g\right)+4H^{+}\left(aq\right)+4e^{-}\rightleftharpoons 2H_{2}O\left(l\right)$