The constituent of air necessary in the rusting process are?

A. O2 and H2O
B. Ar and CO2
C. CO2 and H2O
D. O2 and CO2

Correct Answer:

Option A – O2 and H2O

Explanation

Rust is an iron oxide, a usually red oxide formed by the redox reaction of iron and oxygen in the presence of water or air moisture.