What does it mean to make weak acid from strong acid?

To put it simply, weak acid can be obtained by chemical reaction with strong acid, but not the other way around, for example, sulfuric acid hydrochloric acid and calcium carbonate can be reacted to obtain carbonic acid, but sulfuric acid cannot be made with carbonic acid.

In chemical reactions, strong acids are generally used as reactants, but there are exceptions.

Dilute it with water to make a weak acid.

Strong acids can be replaced by weak acids.

Strong acid means that acid dissolved in water can ionize into hydrogen ions and acid ions to a large extent, and weak acid is relative to strong acid, which refers to the partial ionization of acid in solution, and most of it exists in a molecular state in solution. The general acid-to-acid reaction is actually a metathesis reaction, and whether this reaction can occur depends on the strength of the acid but also considers whether there is precipitation, gas, and the formation of high or low boiling point acids.

For example, phosphoric acid (a moderately strong acid) is used to produce Hi and HBR (both of which are stronger acids than hydrochloric acid). Although phosphoric acid is a weak acid, the reaction can occur due to the formation of gas.

For example, perchloric acid is formed by the reaction of sulfuric acid with barium perchlorate, although we say that perchloric acid is more acidic than sulfuric acid, but because of the formation of barium sulfate precipitation, the reaction can also occur.

Therefore, we should understand it for strong acid to make weak acid, and do not simply classify it as strong acid to make weak acid when there is an acid and salt that reacts with salt to form another acid and salt.

It is not necessary to make a strong acid to make a weak acid, there are special circumstances: such as: H2S Cuso4 H2SO4 Cus

This reaction mainly produces a substance that is insoluble in strong acids (i.e., insoluble substances in ionic reactions).

In general, weak acids cannot make strong acids, but there are exceptions.

The strength of an acid refers to the ability of an acid to lose hydrogen ions in solution, that is, the size of the ionization constant of the acid. The greater the ionization constant, the greater the strength of the acid. Since weak acids have a smaller ionization constant, it cannot make strong acids.

However, in some cases, there are acids that can increase the concentration of acids in the solution, making the solution more acidic. This acid is usually a weak acid, but it is capable of producing protons from other weak acids or inorganic salts in the solution, increasing the concentration of the acid in the solution.

For example, nitric acid can increase the concentration of hydrogen ions in sulfuric acid, making sulfuric acid more acidic.

Alternatively, aqua regia can be obtained by mixing concentrated Hno3 with concentrated HCl according to the volume ratio of 1 3.

hno3+3hcl=2h2o+cl2+nocl

In the reaction you described above, sulfurous acid is produced by the reaction of sulfur dioxide and water.

Sulfurous acid is a weak acid, whereas barium nitrate is a strong acid. Therefore, during this reaction, the weak acid sulfurous acid is indeed made into the strong acid barium nitrate.

The chemical equation for this reaction can be expressed as: 2SO2 + H2O ->H2SO3

All the substances used in this reaction are acids, but since they have different ionization constants, they also have different acid strengths.

In general, weak acids do not directly produce strong acids.

Weak acid refers to an acid that cannot convert all the acidic ions into hydrogen ions in an aqueous solution. That is, the acidic ions of the weak acid can combine with the water molecules to form carboxyl groups in the aqueous solution, so the concentration of the weak acid in the aqueous solution is relatively low.

A strong acid is an acid that can convert all the acidic ions into hydrogen ions in an aqueous solution. That is, the acidic ions of strong acids can hardly bind to water molecules in aqueous solution, so the concentration of strong acids in aqueous solution is relatively high.

Therefore, if you want to make a strong acid from a weak acid, you can try to enhance the acidity by increasing the concentration of the solution or lowering the pH, but doing so may introduce certain risks, such as possible corrosion of the container, or harmful by-products. Therefore, it is recommended that you carefully read the relevant literature before conducting such experiments and ensure that safety measures are in place.