Why is excessive sulfuric acid added to rust?

Rust rarely adds excessive sulfuric acid, and generally dilutes sulfuric acid.

to remove rust, and adding too much sulfuric acid will cause the iron to also be broken down, and hydrogen will be generated. There are two main chemical formulas:

fe2o3 + 3h2so4 = fe2(so4)3 + 3h2ofe + h2so4 = feso4 + h2↑

When hydrogen sulfide gas is produced by reacting ferrous sulfide with dilute hydrochloric acid or dilute sulfuric acid, because it is prepared in a Qipu generator or its simple device, the sulfur in the oxide layer on the solid surface of ferrous sulfide does not react with dilute hydrochloric acid and dilute sulfuric acid, which hinders the contact between ferrous sulfide and hydrogen ions in the acid solution (that is, although ferrous sulfide is insoluble, it can be dissolved a little after all, and the dissolved part completely ionizes the ferrous ions and sulfur anions). At this time, there are almost no sulfur anions in the solution, and there is very little hydrogen sulfide in combination with hydrogen ions. On the other hand, at room temperature, the reaction of ferric tetroxide with dilute hydrochloric acid and dilute sulfuric acid is relatively slow, and the dissolved ferric tetroxide will also consume more hydrogen ions, so that the concentration of hydrogen ions decreases, and the chemical equation of the reaction Fe(FeO2)2+8H+=Fe2++2Fe3++4H2O.

1.Dilute sulfuric acid: the main component of rust is Fe2O3, and adding excess sulfuric acid is to remove Fe2O3

Fe2O3+3H2SO4=Fe2(SO4)3++3H2O, followed by the reaction of iron and sulfuric acid.

fe+h2so4=feso4+h2

2.Concentrated sulfuric acid: Concentrated sulfuric acid is passivated iron, which forms an oxide film on the surface for easy transportation.

First of all, it is still to remove the rust, and then to passivate the iron.

3Fe + 4H2SO4 (concentrated) = Fe3O4 + 4SO2 + 4H2O (passivation equation).

The phenomenon of the reaction between rust and imitation Hengtan dilute sulfuric acid is: the reddish-brown solid gradually disappears, and the solution gradually changes from colorless to light yellow.

A chemical formula for the reaction of rust with dilute sulfuric acid.

For Fe2O3+3H2SO4=Fe2(SO4)3+3H2O, rust is a reddish-brown solid, which will gradually disappear after reaction with dilute sulfuric acid, and the iron ion Fe(3+) generated is pale yellow in solution.

Other common colored ions are: copper ions.

Cu(2+) is blue, ferrous Fe(2+) is light green, and manganese Mn(2+) is pale pink.

The phenomenon is that the reddish-brown solid gradually disappears, and the trapped culture solution gradually changes from colorless to light yellow. The chemical equation of the reaction between rust and dilute sulfuric acid is Fe2O3+3H2SO4=Fe2(SO4)3+3H2O, and iron is a reddish-brown solid made of lead rust, which will gradually disappear after reaction with dilute sulfuric acid, and the iron ions Fe(3+) generated are light in solution.

Rust can be removed with dilute sulfuric acid.

The principle of removing rust with dilute sulfuric acid: because the two can react. Basic oxides.

Reacting with acid, its reaction formula is as follows: Fe O +3 H So Fe (So) 3 HO, where the valency of iron.

It is a positive trivalent. The aqueous solution of Fe (SO) is brownish-yellow, and the solution has strong oxidizing properties.

Pay attention to the rumors and items.

1. Control the concentration of pickling solution.

During the rust removal process, the water will gradually evaporate, so water should be added at any time to adjust the formula to control the process range, so as to avoid corrosion caused by excessive acid concentration and wide bends of the workpiece.

2. Keep the acid clean.

In the process of acid rust removal, if alkali and other dirt are introduced, the composition of the acid will gradually change, affecting the pickling efficiency. Therefore, in order to obtain satisfactory pickling results, it is necessary to regularly inspect, analyze, and replace the acid solution to keep the acid solution properly clean.

Sulfuric acid can remove rust. The principle of removing rust with dilute sulfuric acid: because the two can react. Basic oxides.

Reacting with acid, its reaction formula is as follows: Fe O +3 H So Fe (So) 3 HO, where the valency of iron.

It is a positive trivalent. The aqueous solution of Fe (SO) is brownish-yellow, and the solution has strong oxidizing properties.

Sulfuric acid for agricultural useIn agricultural production, sulfuric acid is increasingly being used to improve high pH levels.

of calcareous soils. Over the past 20 years, urea.

Sulfuric acid fertilizer yields have increased dramatically and are widely used in the soils of the western states of the United States.

The injection of sulfuric acid into the dairy farm lake and the change of the pH of the lake water can solve several air and water quality problems caused by the process of captive livestock, and the application of sulfuric acid into agricultural soil and water, its main role is to dissolve carbonates of calcium, magnesium and bicarbonate. These calcium and magnesium salts then replace the exchangeable sodium salts, which are then removed by immersion with water.

When carbonate and bicarbonate are decomposed, sulfuric acid reacts with more inert substances to release plant nutrients such as phosphorus and iron. Simply lowering the pH of the soil can cause solubility of many elements.

changes to increase their potency on plants.

fe2o3+6h+==2fe3++3h2o。

According to the chemical equation of rust and dilute sulfuric acid, the main component of rust is iron oxide, and in the process of reacting with dilute sulfuric acid, oxygen reduction reaction can occur to generate iron sulfate and aquarium, so the chemical reaction equation is Fe2O3+6H+==2Fe3++3H2O.

During the reaction between rust and dilute sulfuric acid, the divalent iron ions in the rust will form trivalent iron ions after reduction, and the iron ions will appear pale yellow in the solution.

Acid and iron oxide produce salt and water, e.g. Fe2O3 + 3H2SO4 == Fe2(SO4)3 + 3H2O, so rust can be removed.

Acid undergoes a displacement reaction with iron, e.g. iron and dilute sulfuric acid Fe + H2SO4 = FeSO4 + H2, which in turn accelerates the corrosion of iron.

Because the knives used in sauerkraut are easily oxidized to rust iron oxide, dilute hydrochloric acid and ferrous iron oxide will undergo a chemical reaction to form green iron and water, and then iron chloride is dissolved in water, so it can remove rust.

Dilute hydrochloric acid Fe2O3+6HCl=2FeCl3+3H2O

The rust gradually disappears, and the solution changes from colorless to yellow.

dilute sulfuric acid Fe2O3+3H2SO4=Fe2(SO4)3+3H2O; The red rust is gradually dissolved in the washed sulfuric acid, and the color of the solution changes from colorless to yellow solution.

fe2o3+3h2so4=fe2(so4)3+3h2o;The red rust is gradually dissolved in the washed sulfuric acid, and the color of the solution changes from colorless to yellow solution.

Rust: Fe2O3

It is yellow when dissolved.

Equation: Fe2O3+3H2SO4===Fe2(SO4)3+3H2O has bubbles because Fe+H2SO4===FeSO4+H2O

Fe2O3 rust dissolves and forms ferric ions, and the solution is yellow.

Rust: Fe2O3

It is yellow when dissolved.

Equation: Fe2O3+3H2SO4===Fe2(SO4)3+3H2O solution is light green (FeSO4) Fe+H2SO4=FeSO4+H2 The bubble is hydrogen.