Why do we need to paint iron objects?
Is rusting of iron is Reversible change or Irreversible?

Rusting of iron is a redox reaction. When iron is exposed to the environmental condition it terribly reacts with water and air and ends up with iron rusting. Iron articles are therefore painted off so that iron can not react with water and air.

Iron reacts with moist air to form a new compound called rust with molecular formula Fe₂O₃. nH₂O. This oxide layer, rust is not stable and falls off after a certain time.

Here is the word equation for the reaction:

Thus rusting of iron is an irreversible change i.e. Rust once formed can not be converted back into iron.