Who knows the main physical properties and uses of sulfuric acid?

10 Properties and uses of sulfuric acid (H2SO4).

Physical properties Pure sulfuric acid is a colorless, viscous, oily liquid.

Not easy to volatile. Concentrated sulfuric acid has strong water absorption and corrosiveness. When dissolved in water, a large amount of heat is released.

Chemical properties Dilute sulfuric acid has the general properties of acids.

1) Follow the indicator.

The purple litmus test solution turns red, and the colorless phenolphthalein test solution does not change color.

2) Reacts with reactive metals.

zn+h2so4===znso4+h2↑

fe+h2so4===feso4+h2↑

3) React with basic oxides.

CuO+H2SO4===CuSO4+H2OFE2O3+3H2SO4===Fe3(SO4)2+3H2O4) reacts with the base to form salt and water.

2NaOH + H2SO4 === Na2SO4 + 2H2OCU (OH) 2 + H2SO4 === CuSO4 + 2H2O5) reacts with certain salts (barium chloride and carbonate).

H2SO4+BACL2===BASO4 +2HCLNa2CO3+H2SO4===NA2SO4+H2O+CO2 concentrated sulfuric acid has strong oxidizing properties.

Hydrogen cannot be produced from concentrated sulfuric acid.

Test method with litmus turning red to prove that it is an acid; Add bacl2 solution to generate a white precipitate, and then add dilute nitric acid, the precipitate does not disappear, which proves that it is sulfuric acid.

Uses: Sulfuric acid is an important chemical raw material.

production of fertilizers and pesticides; Rust removal of metal, etc.

The physical properties of sulfuric acid are as follows:

1. Pure sulfuric acid is generally a colorless oily liquid with a density of cubic meters per gram and a boiling point of 337 degrees Celsius.

It can be miscible with water in any proportion, and at the same time release a large amount of heat, making water boil. When heated to 290 degrees Celsius, sulfur trioxide begins to be released.

Finally, it becomes an aqueous solution of 10% and boils at 317 degrees Celsius to become an azeotropic mixture.

2. The boiling point and viscosity of sulfuric acid are higher because of the strong hydrogen bonds inside its molecule. Due to the dielectric constant of sulfuric acid.

higher, so it is an electrolyte.

good solvent.

3. Pure sulfuric acid is a very polar liquid, and its dielectric coefficient is about 100. Because molecules can proton each other, resulting in extremely high electrical conductivity.

Differences in concentration:

Although concentrated and pure sulfuric acid can be produced and is infinitely stable at room temperature (the so-called reaction of decomposition into a constant boiling substance occurs at high temperatures close to the boiling point), the freezing point of pure sulfuric acid is pure.

Too high (, so in order to facilitate transportation, 98% sulfuric acid is usually made, so the general "high concentration of sulfuric acid" refers to the concentration of 98% sulfuric acid.

1. Basic physical properties

The mass fraction of H2SO4 in the commonly used concentrated sulfuric acid is;

The density is; The amount concentration of the substance is:

When the concentrated sulfuric acid is dissolved, a large amount of heat is released, so when the concentrated sulfuric acid is diluted, it should be "acid into the water, along the wall of the vessel, slowly poured, and constantly stirred." ”

2. Water absorption is the property of concentrated sulfuric acid, not the property of dilute sulfuric acid.

3. The water absorption of concentrated sulfuric acid refers to the strong combination of concentrated sulfuric acid molecules with water molecules to generate a series of stable hydrates and release a large amount of heat: H2SO4 + NH2O ==H2SO4·NH2O, so the process of water absorption of concentrated sulfuric acid is a process of chemical change, and water absorption is the chemical property of concentrated sulfuric acid.

4. Concentrated sulfuric acid can not only absorb general free water (such as water in the air), but also absorb water in some crystalline hydrates (such as CuSO4·5H2O, Na2CO3·10H2O).

Chemical properties of concentrated sulfuric acid

1.Dehydration.

Dehydration refers to the process of concentrated sulfuric acid to remove non-free water molecules or to remove hydrogen and oxygen elements from organic matter according to the ratio of water to hydrogen and oxygen atom composition. As far as sulfuric acid is concerned, dehydration is the property of concentrated sulfuric acid, not dilute sulfuric acid, concentrated sulfuric acid is dehydrated and very dehydrated, and it is removed according to the composition ratio of water during dehydration.

2.Strong oxidation.

1) React with metals.

At room temperature, concentrated sulfuric acid can passivate metals such as iron and aluminum. The main reason is that the sulfuric acid molecules are combined with these metal atoms to form a dense oxide film, which prevents hydrogen ions or sulfuric acid molecules from continuing to react with the metal, such as iron, which is generally believed to form Fe3O4.

When heated, concentrated sulfuric acid can react with all metals except gold and platinum to form ** metal sulfate, which itself is generally reduced to SO2.

Cu + 2H2SO4 (concentrated) = CuSO4 + SO2 + 2H2O

2Fe + 6H2SO4 (concentrated) = Fe2(SO4)3 + 3SO2 + 6H2O

ZN+2H2SO4 (concentrated) ==ZNSO4 +SO2 +2H2O

In the above reaction, sulfuric acid exhibits strong oxidation and acidity.

2) React with non-metals.

Hot concentrated sulfuric acid can oxidize non-metallic elements such as carbon, sulfur, and phosphorus to oxides or oxygenated acids in their ** state, and itself is reduced to SO2. In this type of reaction, concentrated sulfuric acid only exhibits oxidation.

Physical properties of concentrated sulfuric acid:

Pure sulfuric acid is a colorless, odorless, oily liquid. The mass fraction of H2SO4 in the commonly used concentrated sulfuric acid is , its density is , and the amount and concentration of its substance is . , melting point:

10℃；Boiling Point: 338. Sulfuric acid is a strong acid with a high boiling point and difficult to volatilize, which is soluble in water and can be miscible with water in any ratio.

When the concentrated sulfuric acid is dissolved, a large amount of heat is released, so when the concentrated sulfuric acid is diluted, it should be "acid into the water, along the wall of the vessel, slowly poured, and constantly stirred."

Physical Properties of Sulfuric Acid:

1. Pure sulfuric acid is generally a colorless oily liquid;

2. Density g cm;

3, boiling point 337;

4. It can be miscible with water in any proportion, and at the same time release a large amount of heat to make the water boil;

5. The melting point of sulfuric acid is that adding water or sulfur trioxide will reduce the freezing point.

Chemical properties of sulfuric acid:

Corrosive.

1. Corrosiveness: It can react with most metals (more active than copper) and most metal oxides to generate corresponding sulfate and water;

2. It can interact with the indicator to make the purple litmus test solution red, so that the colorless phenolphthalein test solution does not change color.

3. It can react with alkali to generate corresponding sulfate and water;

4. It can react with pre-hydrogen metal under certain conditions to generate corresponding sulfate and hydrogen;

5. It can react with the salt that the acid ion contains is weaker than the sulfate ion to generate the corresponding sulfate and weak acid;

Concentrated sulfuric acid characteristics:

1. Dehydration: Dehydration refers to the process of removing non-free water molecules from concentrated sulfuric acid or removing hydrogen and oxygen elements from organic matter according to the ratio of hydrogen and oxygen atom composition of water.

2. Strong oxidation, reducing products: concentrated sulfuric acid may be reduced to SO2, S or H2S due to the amount of reducing agent and different types of Hu Hong.

The properties of sulfuric acid are as follows:

Sulfuric acid (chemical formula H2SO4) is a common inorganic compound with strong oxidizing and corrosive properties. The following describes the macro-taking properties of sulfuric acid from the aspects of morphology, liquid state and solid state.

1.Form of sulfuric acid

Sulfuric acid is a colorless, dense, oily liquid with a very strong sulfuric acid smell. At room temperature, concentrated sulfuric acid has a density of approximately and is one of the densest of many chemicals. In addition, concentrated sulfuric acid is also hygroscopic, meaning that it can absorb moisture from the surrounding air, causing its concentration to decrease.

2.Liquid nature of sulfuric acid

1) Concentrated sulfuric acid can react quickly with water and emit a strong white smoke. This is because a violent reaction of exothermic interthermy occurs between the two, which is even capable of boiling the mixture violently.

2) It cannot react directly with alkalis, but forms metal salts with metal oxides. This metal salt is called sulfate.

3) It has strong acidity and can strongly corrode non-metals.

4) It can be used as a dehydrating agent, which can pump out the water in many organic compounds and generate a lot of heat.

3.Solid nature of sulfuric acid

Sulfuric acid can solidify at low temperatures into a colorless and transparent crystal, called copper sulfate. Compared with liquid sulfuric acid, copper sulfate is relatively less corrosive and oxidizing, but still has strong hygroscopicity.

In addition, due to the strong oxidizing and corrosive nature of sulfuric acid, it needs to be used correctly in chemical experiments and industrial production. When operating, you need to be careful and cautious, and you must wear protective clothing or gloves with strong protection to avoid causing harm to the human body. At the same time, sulfuric acid needs to be stored in specific containers, and contact with other chemicals should be avoided to avoid chemical reactions.

Pure sulfuric acid is generally a colorless oily liquid with a density of g cm and a boiling point of 337, which can be miscible with water in any proportion, and at the same time release a large amount of heat to make the water boil. When heated to 290, sulfur trioxide is released, and finally becomes an aqueous solution, which boils at 317 and becomes an azeotropic mixture.

The boiling point and viscosity of sulfuric acid are high, and the reason for this is that the hydrogen bonds inside its molecules are strong.

Due to the higher dielectric constant of sulfuric acid, it is a good solvent for electrolytes, whereas solvents as a non-electrolyte are less ideal.

The melting point of sulfuric acid is that the freezing point will decrease when added to water or sulfur trioxide.

Differences in concentration:

Although it is possible to produce concentrated and pure sulfuric acid, it is infinitely stable at room temperature.

The so-called reaction of decomposition into constant boiling matter occurs at high temperatures close to the boiling point), but the freezing point of pure sulfuric acid is too high (so 98% sulfuric acid is usually made in order to facilitate transportation, so the general "high concentration of sulfuric acid" refers to the concentration of 98% sulfuric acid).

In addition, sulfuric acid has different applications at different concentrations, and the following are some common concentration levels:

Sulfuric acid can also be made into other forms. For example, oleum can be made by introducing high concentrations of SO3 into sulphuric acid, and the concentration of sulphuric acid is usually based on the percentage of SO3 or the percentage of H2SO4, which can be used as both.

The concentration of what is commonly referred to as "oleum" is 45% (containing 109% H2SO4) or 65% (containing H2SO4).

When the ratio of SO3 to H2SO4 is 1:1, the product is pyrosulfuric acid (H2S2O7), pyrosulfuric acid is solid, and the melting point is 36.

Polarity and conductivity.

Pure sulfuric acid is a very polar liquid with a dielectric coefficient of about 100.

Because molecules can proton each other, causing it to be extremely conductive, a process known as proton self-migration.