Iron is produced when it encounters acid, and what acid or acid will passivate when iron encounters

Answer: 1. Elemental iron meets sulfuric acid to form ferrous sulfate and hydrogen.

Rule: Iron is formed as divalent iron in displacement reactions (e.g., iron and copper sulfate reactions).

2. Iron sulfate is generated by the reaction of iron-containing compounds such as ferric oxide (except ferrous oxide) and sulfuric acid, because the valence of the elements remains unchanged in the metathesis reaction, and it turns out that ferric iron is still ferric iron after the reaction.

Iron oxide reacts with sulfuric acid to form ferrous sulfate and water, but it will be oxidized into iron sulfate by oxygen in the air over time.

3. Not all substances formed by iron encountering acids are ferrous iron.

Divalent iron is formed when iron encounters non-oxidizing or very weak oxidizing acids, such as dilute sulfuric acid, hydrochloric acid, acetic acid, etc.

When iron encounters highly oxidizing acids, trivalent iron will be generated, such as concentrated sulfuric acid, nitric acid, etc., and hydrogen will not be generated at this time.

When encountering elemental acid, it is iron sulfate, because most of the elemental iron is +2+3 valence, and the formation depends on the valence system of iron, which is called iron sulfate, and the second is called ferrous sulfate.

It reacts with dilute sulfuric acid to ferrous iron because it is not oxidizing enough to be oxidized to 3-valent iron ions.

Elemental iron reacts with acid to form ferrous salts. The salt formed by the reaction with dilute sulfuric acid to form ferrous sulfate and hydrogen iron oxide reacts with acid depends on whether it is ferrous oxide or iron oxide, the former to form ferrous salts and the latter to form iron salts.

To add to the third article of the third:

When Fe encounters a strong oxidizing acid, the product is related to the quantity, and when Fe is less, 3-valent is generated.

2 more prices.

It is generally the formation of ferrous iron.

It is re-oxidized to form 3-valent iron.

So the green iron solution will turn red?

The phenomenon is that a large number of bubbles are produced on the surface of the iron, and the solution gradually turns light green.

Iron vs hydrochloric acid chemical equation: Fe + 2HCl = FeCl + H Iron vs sulfuric acid chemical equation: Fe + H so = Feso + H <

Hello, you need to understand these concepts about this issue.

Passivation: is due to the oxidation of the metal.

Matter acts, and when it acts, it is formed on the surface of a metal.

A very thin, dense, well-covering one that adheres firmly to the metal surface of the limb ulnar.

Passivation film. This film exists in separate phases, usually compounds of oxidized metals. It plays the role of completely separating the metal from the corrosive medium, preventing the metal from coming into contact with the corrosive medium, so that the metal basically stops dissolving and forms a blunt state to achieve the effect of anti-corrosion.

Concentrated sulfuric acid. It has a strong concentration when the deficit state is high.

oxidation, which is one of the biggest differences between it and dilute sulfuric acid.

Sold hungry with iron and aluminium in the encounter with concentrated sulfuric acid and concentrated nitric acid.

It will be oxidized, and the metal surface will be passivated to form an oxide film, thereby preventing the metal from continuing to react with concentrated sulfuric acid and concentrated nitric acid.

As long as the amount of acid is sufficient, there will be no iron residue.

For example, in the reaction with hydrochloric acid: Fe + 2HCl = FeCl2 + H2, for every 56 grams of iron, 73 grams of HCl are required to participate in the reaction. (Based on the concentration of concentrated hydrochloric acid, the quality of concentrated hydrochloric acid required is 200g).

Another example is with sulfuric acid: Fe + H2SO4 = FeSO4 + H2, for every 56 grams of iron, 98 grams of H2SO4 are needed to participate in the reaction. (Based on the concentration of 20% dilute sulfuric acid, the mass of the sulfuric acid solution required is 490 grams).

Sulfuric acid here refers to dilute, because dilute sulfuric acid and hydrochloric acid are both non-oxidizing acids, so low-cost salts are generated, and nitric acid is oxidizing regardless of concentration, so ** salts are generated.

Iron and acetic acid do not react.

When galvanic corrosion occurs in an acidic solution, hydrogen gas is released, and this corrosion is called hydrogen evolution corrosion.

Principle: Carbon is generally found in steel products. In moist air, the surface of steel absorbs water vapor to form a thin film of water.

When carbon dioxide is dissolved in the water film, it becomes the electrolyte carbonic acid.

Increases the number of h in the water. According to the knowledge of electrochemistry.

In such an environment, it is lamented that steel constitutes countless tiny galvanic cells with iron as the negative electrode, carbon as the positive electrode, and an acidic water film as the electrolyte solution.

Negative electrode (iron): Iron is oxidized Fe-2e=Fe2+

Positive electrode (carbon): H in solution

It is restored for 2h+

2e=h2↑

In the end, Fe2+ and air O2 redox were finally obtained (rust.

Yes, it reacts with acid to form ferrous ions, and ferrous ions and water in the air form ferrous hydroxide, and then after oxidation, dehydration and air drying become rust.

The corrosion of steel under acidic conditions is a relatively fast hydrogen evolution corrosion;

And the corrosion under medium alkaline conditions is a slower oxygen absorption corrosion!!

Summary. Hello dear, according to the situation you described, if the iron is acidified and other weak acids such as citric acid are added, if bubbles appear, it means that the iron is not completely oxidized. Because iron produces hydrogen gas during the oxidation process, if hydrogen is still present in the solution, it will continue to produce bubbles when a weak acid is added, indicating that there are still unoxidized iron ions present in the solution.

If you want to completely oxidize the iron, you can add an oxidizing agent such as hydrogen peroxide or sodium peroxide.

Hello dear, according to the situation you described, if a weak acid such as citric acid is added before and after the failure of iron acidification, if bubbles appear, it means that the iron is not completely oxidized. Because iron will produce hydrogen gas during the oxidation process, it will continue to produce bubbles when weak acid is added, indicating that there are still unoxidized iron ions in the solution. If you want to completely oxidize the iron, you can add an oxidizing agent such as hydrogen peroxide or sodium peroxide.

Can you solve question 30?

Classmate, I'm very sorry, don't send **ha, send **can't help.

I need you to send me the question in writing.

I'm offline, you can rest early, I wish you good dreams and good night.

The reaction between acid and alkali is often used to regulate the acidity and alkalinity in experiments, such as treating acidic wastewater, Ca(OH)2+2HCl=CaCl2+2H2O

Used to neutralize excess stomach acid.

al(oh)3

3hclalcl3+3h2o

The reaction of acid and metal, zinc and dilute sulfuric acid are commonly used in the laboratory to produce hydrogen Zn + H2SO4 = ZnSO4 + H2, and foods containing very fine iron powder are commonly used in life to supplement iron Fe + 2HCL = FeCl2 + H2, and inactive metals (such as Cu) are resistant to acid corrosion.

The reaction of acid and metal oxygenation is often used to remove rust Fe2O3+6HCl=2FeCl3+3H2O, remove metal oxide film, etc.

The reaction between acid and salt is often used for the identification of chloride ions in tap water, HCl+AGnO3=AGCL+HNO3,

Laboratory-made carbon dioxide C worker +2HCl=CaCl2+H2O+CO2 Li Xupai, etc.

As long as the amount of acid is sufficient, there will be no iron residue.

For example, with hydrochloric acid. Reaction: Fe

2hclfecl2+

H2, for every 56 g of iron, takes 73 g of HCl to participate in the reaction. (Based on the concentration of concentrated hydrochloric acid, the quality of concentrated hydrochloric acid required is 200g).

Another example is with sulfuric acid: Fe

h2so4feso4

H2, for every 56 g of iron, requires 98 g of H2SO4 to participate in the reaction. (Based on the concentration of 20% dilute sulfuric acid, the mass of the sulfuric acid solution required is 490 grams).