11.4.1 Rusting and Rust Prevention True/False

Rust consists mainly of hydrated iron(III) oxide (Fe₂O₃·xH₂O).

Both water and oxygen are necessary for iron to rust.

Rust formation is accelerated by the presence of salt.

Painting iron surfaces can effectively prevent rust as long as the paint remains intact.

Oiling or greasing the moving parts of machinery is an effective way to protect them from rust.

Coating steel structures with plastic, such as PVC, can prevent rust.

Galvanizing involves dipping steel objects into molten iron.

Sacrificial protection involves attaching bars of zinc to steel structures.

Zinc is less reactive than iron in the reactivity series.

Zinc corrodes in preference to iron when in contact with it.

Gas and water pipes made of iron and steel are connected to magnesium for protection against rust.

Sacrificial protection continues as long as the protective metal remains in contact with the iron structure.