Question

Which of the following phenomenon takes place when iron converts to rust?

• A. Iron gets oxidised to +3 oxidation state
• B. Iron gets reduced to +2 oxidation state
• C. Iron gets oxidised to +2 oxidation state
• D. Iron neither gets oxidised nor reduced

Answer 1

The correct option is A Iron gets oxidised to +3 oxidation state

Rusting of Iron may be considered as an electrochemical phenomenon. It occurs in presence of both, moisture and oxygen.

Rusting of Iron (overall reaction):
$2Fe\left(s\right)+\frac{3}{2}{O}_2\left(g\right)+x{H}_{2}O\left(l\right)\rightleftharpoons F{e}_2{O}_3.x{H}_{2}O\left(s\right)$
Here iron changes its oxidation state from 0 to +3