Rusting of Iron is due of formation of

Rusting of iron is a chemical process that occurs when iron is exposed to moist air for a prolonged period [c4]. The process involves an oxidation reaction where iron reacts with oxygen and water to form a brown, flaky substance [c1][c3]. Chemically, rust is primarily composed of hydrated ferric oxide, represented by the formula Fe2O3·nH2O [t1][t5]. While the initial stages of corrosion may involve the formation of ferrous ions (Fe2+) and iron(II) hydroxide, these are further oxidized in the presence of oxygen to the ferric state (Fe3+) [t2][t9]. The final stable product that characterizes the brown deposit known as rust is the hydrated form of iron(III) oxide, also known as ferric oxide [t5][t6]. Therefore, hydrated ferric oxide is the most accurate description of rust's chemical composition.

Sources

1. [1] Science-Class VII . NCERT(Revised ed 2025) > Chapter 5: Changes Around Us: Physical and Chemical > 5.3.1 Rusting > p. 62
2. [2] Science-Class VII . NCERT(Revised ed 2025) > Chapter 4: The World of Metals and Non-metals > Activity 4.5: Let us experiment > p. 50
3. [3] Science , class X (NCERT 2025 ed.) > Chapter 3: Metals and Non-metals > 3.5 CORROSION > p. 53