Rust does not grow after reaching a certain amount in a closed container, why?

In a closed container, the iron has consumed oxygen or water vapor, and no longer can form rust, so the rust does not increase after reaching a certain amount in the closed container.

Iron rust is a complex chemical reaction between iron and oxygen and water vapor in the air to produce rust whose main component is iron oxide.

Iron rusts, everyone is used to it. But the same iron products, some are easy to rust, and some are difficult to rust. For example, iron products placed in a damp place are easy to rust, while iron products placed in a dry place are less prone to rust; Iron products that are exposed to the air are prone to rust, but after painting or plating some metals that are not easy to rust, iron products are not easy to rust.

Why is this happening? What are the factors that cause iron to rust? Just when we were wondering, we saw this news item on the Internet:

The plant of a foreign chemical company has a steel container that is used to store magnesium chloride. At one point, the container stopped working because it needed maintenance, and the factory emptied it. Magnesium chloride in the container and rinse the container several times.

The two workers then entered the steel container for repairs and immediately passed out. When people found out, they were immediately rescued and taken to the hospital. One was rescued and escaped, and the other tragically died.

What causes death? Does the container contain toxic gases? People tested the air inside the steel container and found no toxic gases, but were surprised to find that the oxygen content in the air inside the container was much lower than normal.

Why is there a lack of oxygen in the container? After analysis, it was found that the problem was with the container itself, because the container was rusty. We discussed:

This indicates that iron needs to consume oxygen to rust. But is iron rust only related to oxygen? What role did water and magnesium chloride play in this incident?

Therefore, the three of us speculated based on their daily life experience and the background of the above incidents: the rust of iron products may be related to water, air and other factors.

The essence of iron rust is that the surface of iron reacts chemically with oxygen to form iron oxide.

In an airtight container, there is no wind, sun or rain, so the resulting rust (iron oxide) will cover the surface of the iron. The end result is that the entire surface is covered with a dense layer of iron oxide. Because there is no external force, this layer of rust will always adhere tightly to the surface of the iron, and block the inner layer of iron from contacting the air, which also protects the inner layer of iron from corrosion.

So that the amount of rust does not grow.

As the pressure inside the container increases, there are two things to do: reduce the volume of the container, or fill it with gas.

Obviously, the former can increase the reaction rate.

However, the latter, if the filled gas does not participate in the reaction.

For example: n2+3h2=nh3

In this reaction system, helium is added and the rate of reaction is constant.

Speeding up the reaction rate is essentially increasing the probability of effective collision of particles.

The total number of particles increases when the limbs are added to the non-reactive substances, so even if the pressure is increased, the reaction rate is not affected.

Hello! If the reaction in the gaseous state is a reversible reaction with constant volume, the rate of both positive and negative reactions increases when the pressure increases, so the rate of the macroscopic reaction does not necessarily accelerate. (related to the concentration of reactants and the formation of Wucha pickpockets).

It only represents a personal point of view, don't spray it, thank you.

Do you know why iron rusts?

Iron rusts when left for a long time. Iron is susceptible to rust, not only because of its chemical activity, but also because of external conditions. Moisture is one of the substances that makes iron rust easily.

However, the presence of water alone does not rust iron, and only when the oxygen in the air is dissolved in the water, the oxygen reacts with the iron in the presence of water to form something called iron oxide, which is rust. Rust is a brownish-red substance, it is not as hard as iron, it can easily fall off, and after a piece of iron is completely rusted, the volume can expand by 8 times. If the rust is not removed, the spongy rust is particularly easy to absorb water, and the iron will rot faster.

The so-called balance is the balance of quality, which has nothing to do with proportion.

Liying is in the chemical reaction quality unchanged, why can't it be said? Chemistry has reached chemical equilibrium, but this world,

Able to state that equilibrium has been reached.

Will it be exothermic, or chemical energy will be converted into internal energy, if it is an ideal model of the insulated cup, it is just iron oxide and water that increase the internal energy, if it is just a closed container in life, it will also conduct heat conduction with the container, at least heat radiation will occur to transfer internal energy.

It's still going to be exothermic. Because what happens here is the oxidation reaction of iron, and the oxidation reaction of iron is an exothermic reaction.

Iron powder is difficult to react with water at room temperature, but it can react with hot water under heating conditions.

In fact, whether it is airtight or not has nothing to do with this reaction.

This reaction is not reversible, so it has nothing to do with chemical equilibrium, so a closed reaction system will not be affected.

Iron powder does not react with water, only in humidity and environment can react with oxygen in the air to form rust!Of course if there is very little water can also be reflected, although the container is airtight!But there's still air in the airtight container!

It should be able to react, but the reaction is very slow, and the exothermic release rarely needs to be tested through a special combination!

In the ideal model, it does not exothermic and does not react.