Which state is necessary for rusting of iron ?

Options

A. Absence of `O_2`
B. Presence of `CO_2`
C. Absence of Water
D. Presence of `O_2`

Answer

D

Explanation

Rust is a type of corrosion. It happens to Iron and its alloys when it is exposed to air(oxygen) or water for a long time. Rust slowly decomposes iron into other chemicals. However, impurities in the iron, the presence of water vapor, acids, salts and carbon dioxide hastens rusting. Pure iron does not rust in dry and carbon dioxide free air