Rusting of an article made up of iron is...

Rusting of an article made up of iron is called

corrosion and it is a physical as well as chemical change.

dissolution and it is a physical chane

corrosion and it is a chemical change

dissolution and it is a chemical change

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Rusting of an article made up of iron is called corrosion.
Corrosion is a chemical change because rust is a chemical compound (hydrated iron oxide, `Fe_(2)O_(3)`. `xH_(2)O`) which is totally different from element iron (Fe). Corrosion is
`4Fe+3O_(2)+xH_(2)O to underset("Rust")(ubrace(2Fe_(2)O_(3).xH_(2)O))`
Physical changes are those changes in which no new substances are formed. The substances do not change their identity and they can be easily returned to their original form by some physical processes. e.g., melting of ice, glowing of an electric bulb, breaking of glass tumbler. etc.
On the other hand, chemical changes are those changes in which new substances are formed. The substances involved change their identity and they get converted into entirely new substances, which can not be returned to their original form. e.g., burning of paper, rusting of iron, burning of magnesium wire, etc.

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Rusting of iron is

A decomposition process

A photochemical process

An electrochemical

A reduction process

In the electroplating of silver over an article made of iron , the electrolyte generally used is

`AgNO_(3)`

`AgCl`

`Ag_(2)SO_(4)`

`Na[Ag(CN)_(2)]`

Rusting on the surface of iron involves :

`Fe(s)rarr Fe^(2+)(aq)+2e^(-)` (at anodic site)

`O_(2)(g)+4H^(+)(aq)+4e^(-)rarr 2H_(2)O(l)` (at cathodic site)

`4Fe^(2+)(aq)+O_(2)(g)+4H_(2)O(l)rarr 2Fe_(2)O_(3)(s)+8H^(+)`

`Fe_(2)O_(3)(s)+ xH_(2)O(l)rarr Fe_(2)O_(3). xH_(2)O`