Do all things in iron rust?

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.

To remove rust, you can shovel it off with various tools or soak it in an acidic solution to dissolve it. After removing the rust, the surface of the iron must be treated, coated with a layer of lead, and then painted; Or plating it with other metals that don't rust easily. A more radical approach is to add some other metals to the iron to make a stainless alloy.

The stainless steel we are familiar with is an alloy made by adding a little nickel and chromium to the steel.

The cause of metal rust is mainly the action of electrochemical corrosion and air oxidation, and pure metal or active metal is mainly due to the oxidation reaction between the metal surface and the oxygen in the air, and the metal oxide is generated on the metal surface, that is, rust. If the metal contains more impurities, these impurities will form a chemical galvanic battery with the metal, and electrochemical corrosion will occur, thereby oxidizing the metal to form metal oxides. Some metals rust and produce a dense oxide film that prevents further oxidation, such as:

Alumina. However, the thinning of the oxide film produced after the rusting of some metals accelerates the oxidation of the metal, such as rust.

Iron and oxygen rust when they encounter water or moisture in the air.

Rust is a very common chemical compound whose scientific name is iron oxide (Fe2O3) that rusts when iron and oxygen react in the presence of water or moisture in the air, and green rust occurs when iron reacts with chloride in the underwater environment.

The process of rusting is a combustion reaction similar to fire, when in contact with oxygen, iron reacts with oxygen to form rust, however, unlike fire, the reaction is much slower and does not produce flames. There are certain factors that can speed up the rusting process, such as water that accelerates the reaction, and salt which can also increase the speed of the rusting process.

Iron rusts because it reacts with sighs and hands in moist air, or when it is eroded into oxides by nitrogen in water.

The conditions required for iron to rust are as follows:

1. The active chemical properties of iron itself.

2. Oxygen contained in the air under external conditions.

3. Moisture is one of the substances that makes iron easy to rust.

In summary, it is only when the oxygen in the air is dissolved in the water that the oxygen reacts with iron in the presence of water to form iron oxide, which is rust. Rust is a brownish-red substance, it is not as hard as iron, it can fall off easily, and a piece of iron will swell in volume by 8 times after it is completely rusted.

Iron is prone to rust, and in addition to its chemically active properties, it also has a lot to do with external conditions. Water is one of the substances that make iron rust, but water alone does not rust iron, and only when the oxygen in the air is dissolved in water and reacts with iron, something called iron oxide is formed, which is rust.

Rust is a colloquial name for iron oxide, which is a common chemical compound. Iron oxide (chemical formula Fe2O3) is very common because iron is easily combined with oxidation – in fact, because this process is so easy to occur that pure iron is hardly found in nature. Iron (or steel) rusting is an example of corrosion – it is an electrochemical process that involves an anode (a piece of metal that easily loses electrons), an electrolyte (a liquid that facilitates the movement of electrons), and a cathode (a piece of metal that easily accepts electrons).

While the metal is corroded, the electrolyte can provide oxygen to the anode. When oxygen is fused with metals, electrons are released. When electrons flow through the electrolyte to the cathode, the anode metal disappears as it is washed away by the current or converted into metal cations (e.g. in the form of rust).

To turn iron into iron oxide, three substances are needed: iron, water, and oxygen. These three substances put together make such a change:

When a drop of water falls on an iron object, two things happen almost simultaneously. First, water (a good electrolyte) is combined with carbon dioxide in the air to form weak carbonic acid, which is a better electrolyte than water.

As acid forms and iron gradually dissolves, a portion of water begins to break down into its constituent components – hydrogen and oxygen. Free oxygen is combined with dissolved iron to form iron oxide, which releases electrons at the same time. Electrons flow from the anode (iron) to the cathode (perhaps a metal that is less electrochemically reactive than iron, or another part of this iron).

Salty droplets splashed on acid rain, seawater, and snow roads contain compounds that make them better electrolytes than water, and their presence accelerates the rusting of iron and other forms of corrosion processes on other metals.

Do you understand how the experiment works?

The result of this experiment is that moisture is one of the conditions that makes iron rust easily. Chemists prove:

In absolutely waterless air, iron does not rust after a few years. However, water alone does not rust iron. It has been tried that if a piece of iron is placed in a boiled, airtight distilled water bottle, the iron will not rust.

Only when the oxygen in the air is dissolved in the water will the iron rust.

You don't have to boil and cool distilled water, and you can't tell if it's the water or the oxygen in the water, so you have to remove impurities and remove the oxygen dissolved in the water.

Comparative experiments on iron rusting].

Place 4 clean nails into each of the 4 tubes. Add a small amount of tap water to the first tube so that one part of the nail is immersed in water and the other part is exposed to air; Add tap water to the second tube and immerse all the nails in the water; Fill the third tube with cooled boiling water and plug the rubber stopper tightly; Add a small amount of quicklime or anhydrous calcium chloride solids to the fourth tube and plug the rubber stopper tightly. Observe and record experimental phenomena.

We will observe that the nail in the first test tube rusts the fastest and the most severe, and after a few days, the part of the nail exposed to the air forms a layer of reddish-brown rust on the surface. In the second tube, the nail rusts slowly and to a lesser extent.

The iron nails in the third and fourth tubes were not rusty. Why is the nail in the first test tube rusted the most? Because steel is composed of iron and contains a small amount of carbon, due to the action of moisture, oxygen, carbon dioxide and other substances in humid air, it is easy to form rust on the surface, and the rust is loose and porous, so that the inner layer of iron continues to be corroded and falls off layer by layer.

The iron in the second tube interacts with the oxygen in the water, and the rust rate is slow because there is less oxygen dissolved in the water. There is almost no oxygen in the third tube, and the small amount of oxygen dissolved in the water is almost completely removed during the boiling process, so the nails do not rust. There is oxygen in the fourth tube, but it is almost anhydrous, and quicklime or anhydrous calcium chloride solids remove moisture from the air, and iron does not react with oxygen at room temperature.

There is this experiment in junior high school**:

It probably means that the iron nail is put into three test tubes, one is dry air (sealing) and one test tube is filled with half of the test tube's water, but a part of the iron nail is left in the air, the third test tube is filled with water and submerged with the iron nail, and then sealed with a layer of oil, after a few days, it will be found that only the iron nail in the second test tube is rusty, this experiment proves that iron rust must meet the needs of both air and water, that is to say, the iron nail is most prone to rust in humid air.

Note: The main component that plays a role in the air is oxygen.

The main component of rust is ferric oxide (reddish-brown).

Iron rust is a complex chemical reaction, and the reaction exothermic is a slow oxidation phenomenon.

The first question is that the conditions you give don't seem to be ...... enoughIf the nails are submerged in water, the nails will rust slowly, but at least they will be heavier than air, because there is only water vapor in normal air vapor, and the solubility of oxygen in water is one percent less) so ......

There is no air in the vacuum, so it does not rust.

Appropriate measures are taken according to the conditions under which the iron rusts, such as painting the iron products, plating them with tin or zinc (they form a dense oxide film that separates the contact between the iron and oxygen and water vapor), or adding nickel and chromium to make stainless steel to prevent the iron from rusting.

The main component of the Martian atmosphere (about 95) is carbon dioxide, which has about 3 nitrogen, 1 2 argon, which together is about carbon monoxide and oxygen, and very small amounts of ozone and hydrogen, with a small amount of water vapor.

This means that there is not enough water and oxygen on Mars, so on Mars, iron nails will slowly dry up, that is, they will slowly rust.

But if it is not strictly said (at least in junior high school) that there is no water on Mars (because there is too little, if there is more water, humans can immigrate to Mars, and oxygen can be obtained by electrolysis of water), so it is approximate that iron nails do not rust on Mars.

Iron rusting is a chemical change.

1. Rust is a chemical reaction, which is essentially an oxidation reaction of metals. The most common phenomenon of rust is that iron products are oxidized by long-term exposure to air and oxygen, or are eroded by oxygen in water to become oxides.

2. Moisture is one of the substances that makes iron easy to rust. However, only water does not rust iron, and only when oxygen in the air is dissolved in water, the oxygen reacts with iron in an environment with water to form iron oxide, which is rust.

Hello classmate, iron rust is caused by the chemical reaction between iron and oxygen in the air to produce ferric oxide, commonly known as iron red, I hope mine can help you.