Iron pot joke

Iron pots are prone to rust when exposed to water, so we should use cooking oil to raise the pot before use, and then wipe off the water stains on the surface with a dry cloth after each cleaning to minimize rust.

I once heard a joke that people often lock valuables in the safe. Gold has been hidden in the safe for thousands of years, and it can completely disappear. Iron is put in the safe, and no one will steal it. That's rust. Almost none of the ancient ironware displayed in the museum rusted. Similarly, iron pots will soon be covered with rust if they are not used for several months.

Every year, tens of millions of tons of iron in the world are discarded because of rust. Iron rusts easily, not only because of its active chemical properties, but also because of external conditions. Water is one of the conditions that are easy to rust. Chemists have proved that iron will not rust if it is placed in absolutely anhydrous air for several years, which shows that water is the bane of iron.

However, there are conditions for water to rust iron. People try to put a piece of iron into a boiled and sealed distilled water bottle, and the iron will not rust. It can be proved that iron will rust only if oxygen in the air is dissolved in water. Near the water surface closest to the air, there is also the most dissolved oxygen in the water, so it is easy to rust. Carbon dioxide in the air will rust when dissolved in water. The composition of rust is very complicated, mainly iron oxide, iron hydroxide and basic iron carbonate. After rusting, it is loose and soft. Like a sponge, its volume can expand by 8 times. This spongy rust absorbs water easily and naturally decays faster.

After understanding the causes of iron rust, everyone should know how to protect the iron tools we use every day.