Question

Incorrect statement regarding rusting is

• A. metallic iron is oxidised to $F{e}^{3+}$ ions
• B. metallic iron is reduced to $F{e}^{2-}$ ions
• C. oxygen gas is reduced to oxide ion
• D. yellowish-brown product is formed

Answer 1

Answer: (B)

In the presence of $O_2$ and $H_{2}O$ rusting of iron takes place.
$H^{+}$ions act as a catalyst. It is believed that oxidation of $Fe$ into $F{e}^{2+}$ occurs at a place which act as anode,
$Fe\to F{e}^{2+}+2e^{-}$(oxidation) (at anode) In the presence of $H^{+}$ions $O_2$ is reduced into $H_{2}O$ at a place which acts as cathode
$O_2+4H^{+}+4e^{-}\to 2H_{2}O$ (reduction) $F{e}^{2+}$ formed at anode are oxidised into $F{e}^{3+}$ by air.
$4F{e}^{2+}+O_2+4H_{2}O\to 2F{e}_2{O}_3+8H^{+}$