Question

Rusting of iron nail is
(a) reversible change
(b) irreversible change
(c) periodic change
(d) non-periodic change

Answer 1

(b) irreversible change
Rusted iron cannot be converted back to its original state. Iron reacts with moist air to form reddish brown powdered mass called ferric oxide which is not stable and falls off after sometime and rust once formed cannot be converted back to iron. Here a new product is formed and chemical reaction takes place hence it is an irreversible change.