Pure substances and mixtures definition. Pure substances and mixtures

Each substance consists of certain particles. For example, water is made up of water molecules in which two hydrogen atoms are bonded to one oxygen atom. Water molecules differ in composition, shape, size, properties from the molecules of other substances. If the vessel contains only water molecules and there are no particles of other substances, then such water is a pure substance.

pure substances. Pure substances are characterized by constant physical properties. For example, only pure water boils at 100°C and freezes at 0°C. If salt is dissolved in it, then the boiling point will exceed 100 ° C, and the freezing point will decrease. Therefore, during icy conditions, sidewalks are sprinkled with table salt.

The composition of a pure substance is constant, regardless of how it was mined and where the substance is found in nature.

pure substances called substances that consist of particles of one substance and are characterized by constant physical properties.

See examples of pure substances in Fig. 22.

When we buy salt, sugar, starch in the store, we consider that these are pure substances. However, in these food products there are minor impurities of other substances. Consequently, in nature and in everyday life, substances in their pure form are practically not found.

Mixes. In nature, technology, everyday life, mixtures of two or more substances predominate. Natural mixtures are air, natural gas, oil, milk, sea water, granite, rocks, fruit juices. According to fig. 23 find out in what states of aggregation mixtures can be.

Mixtures known to you that are created and used by man include: building mixtures, gasoline, paints, washing powders, toothpastes, ketchups, mayonnaises, various dishes, etc.

Mixture are two or more substances mixed together. There are solid, liquid, gaseous mixtures.

On fig. 24 shows how citric acid and water prepared a mixture. The molecules of these substances are mixed with each other.

You can also prepare various mixtures, such as tea, soap solution, compote, dough - a mixture of flour, soda and water.

Individual substances in a mixture are called components. The components of a natural mixture of granite are easy to see. In another natural mixture - milk - the components are not visible, although it contains many substances, among them - water, fats, proteins. These components can be determined using a microscope. But to consider the components of such a natural mixture as sea water is not possible even under a microscope.

Mixes are natural and cooked by man. To prepare one mixture, it is necessary to have two or more substances.material from the site

A mixture of water and sugar can remain unchanged for a long time. Natural mixture - after a few days of staying in a warm place, milk begins to separate into components. AT top layer fat accumulates, thickening of protein molecules and liquid become visible under it. To get sour cream, butter and cottage cheese separately, the mixture must be separated.

Divide the mixture means to separate each of its components.

For individual experiments, pure substances are needed. Therefore, they use different ways extraction of particles of another substance from one substance. You will learn about the methods of separating mixtures in the next paragraph.

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Each substance has a set of properties inherent only to it, however, these properties are quite definite only for a single individual substance, not mixed with other substances. Therefore, it is necessary to distinguish between pure substances and mixtures of substances.

PURE SUBSTANCES

Physical and Chemical properties are constant if the substance is pure.

Examples of practically pure substances are some metals, in which the impurity content does not exceed several hundredths or thousandths of a percent by weight. For example, copper with a purity of 99.99% or gold bars, in which its content is expressed in figures of 99.999%. This means that for every 100,000 metal atoms there is only 1 other atom.

Substances that do not contain impurities of other substances are called pure. Any pure substance has a set of properties inherent only to it. The constancy of properties is a sign of the purity of a substance.

MIXTURES OF SUBSTANCES

In nature, substances are almost never found in pure form. Some substances are mixed together with others to form mixtures.

If the mixture consists almost entirely of one substance, then it is usually called the same as this substance itself. Examples of blends you encounter in Everyday life, are given in the figure.

It can be seen that these mixtures consist of several constituent parts- components.

Minerals - a mixture of several substances

Milk is a heterogeneous mixture

SEPARATION OF MIXTURES

Pure substances are rare, for example, in chemical laboratories, in a pharmacy, in chemical plants (examples of pure substances are in the figure).

To get them, you need to learn how to separate mixtures and isolate each substance separately. For this there are various methods separation of mixtures.

SEPARATION OF HETEROGENEOUS MIXTURES

One of the most simple methods separation - upholding. This method is based on the different densities of the mixture components and can be used to separate heterogeneous mixtures of two liquid substances (for example, gasoline - water), liquid and solid substances (for example, sand - water).

A method like filtration, is based on the ability of some porous materials to retain particles that are larger than the pore size of the given material. With the help of filtration, it is possible to separate heterogeneous mixtures of solid and liquid substances (chalk - water, clay - water).

Separation of mixtures of various substances by settling and filtering

SEPARATION OF HOMOGENEOUS MIXTURES

- Evaporation. The method is based on the difference in the boiling points of the mixture components and can be used to separate homogeneous mixtures of solid and liquid substances (salt-water, sugar-water). The evaporation method is usually used when only the solid needs to be isolated from a homogeneous mixture of solid and liquid.

Evaporation. Evaporation of salt in a salt lake

- Distillation (or distillation) based on the difference in boiling points between the components of the mixture. Most often, distillation is used to separate homogeneous mixtures of several liquid components or solid and liquid components. Unlike the evaporation method, distillation is used to isolate all components from a mixture. In chemical laboratories, using this method, distilled water is obtained that does not contain dissolved salts. In the countries of the Middle East, this method is widely used to obtain drinking water from the sea.

Laboratory plant for the distillation of liquids

So today we learned:

Substances that do not contain impurities of other substances are called pure;

A pure substance has constant properties by which it can be distinguished from other substances;

Mixtures are homogeneous and heterogeneous;

Substances can be isolated from a heterogeneous mixture by settling and filtering;

Substances can be isolated from a homogeneous mixture by evaporation and distillation.

Take the paragraph test

Lesson #5

Topic: Pure substances and mixtures.

Target: give the concept of pure substances and mixtures, homogeneous and heterogeneous mixtures; consider natural mixtures: air, natural gas, oil; to acquaint with examples of solid, liquid, gaseous mixtures in nature and everyday life; develop cognitive interest and intellectual abilities; educate attitude to chemistry as one of the fundamental sciences.

Equipment: examples of pure substances (sugar, sulfur, iron filings, distilled water, chalk powder), presentation "pure substances and mixtures", multimedia projector and screen.

During the classes.

IClass organization.

IIThe message of the topic, the objectives of the lesson, the motivation of educational activities.

We have considered the concept of "substance", we know what properties substances have. Today we will get acquainted with the concept of "mixture". Consider how mixtures differ from substances, what types of mixtures are. Let's get acquainted with natural mixtures and mixtures used in everyday life. (Slide 1)

IIIUpdating of basic knowledge.

(Front conversation).

What is a physical body?

What is a material?

What is a substance?

Give examples of substances, materials.

What properties do substances have?

Which properties are called physical and which are chemical?

Describe the properties of water, aluminum, oxygen.

IVLearning new material.

Pure substances and mixtures.

Pure substances have permanent physical properties, because consist of particles of the same type (identical atoms, identical molecules).

Examples: iron, aluminum, soda, distilled water, sugar, oxygen, etc.

Mixes it is a collection of different substances that make up one physical body. Substances that are part of mixtures retain their inherent properties.

Look at my prepared examples of pure substances. Name these substances, describe their physical properties.

Now I will prepare several mixtures: sulfur and 1) iron filings, 2) water and chalk,

3) water and sugar. What are you watching.

Answer: 1) sulfur mixed with iron filings. Teacher's question: can we distinguish between iron filings and sulfur particles? Answer: yes.

Answer: 2) the water became cloudy white color. Teacher: Let's leave this mixture for a while. Let's see what happens to her in a few minutes.

Answer 3) Sugar is dissolved in water. Teacher: Can we see sugar particles among water particles with the naked eye? Answer: no. Teacher: Let's leave this mixture for a few minutes.

Teacher: Tell me, what aggregate states do the substances from which we prepared the mixtures have?

Answer: 1) solid and solid, 2) solid and liquid, 3) solid and liquid.

Teacher: Or maybe a mixture of gaseous substances or a mixture of liquid and gaseous substances.

Listen to the students' answers. We analyze them and establish that such mixtures are possible, moreover, they exist: air, oxygen dissolved in water.

We return to mixtures of water and chalk, water and sugar. We see that the chalk has settled, and we clearly distinguish between a layer of chalk below and a layer of water above it. The sugar solution remained unchanged.

Homogeneous (homogeneous) and heterogeneous (heterogeneous) mixtures. (Slide 3)

Mixtures in which particles of their constituent substances are visible to the naked eye or under a microscope are called heterogeneous or heterogeneous.

A mixture in which even with the help of magnifying instruments it is impossible to see the particles of its constituent substances is called homogeneous or homogeneous.

Natural mixtures, mixtures used in everyday life. (Teacher's story).

One of the most favorite materials of sculptors and architects is marble (Slide 4). The color of this rock is surprisingly diverse: milky white, gray, pinkish. The whimsical pattern pleases the eye. (Slide 5) Marble is obedient and pliable in the hands of the master, it is easily processed and perfectly polished to mirror shine. (Slide 6) Marble is a material from which you can make facing tiles, statue or column of the palace. A tile, a statue, a column is physical bodies, products. But the basis of marble is a substance called calcium carbonate. The same substance is part of other minerals: chalk, limestone.

Now let's think about why marble is different color? Why does a unique pattern play on its surface?

Correctly. Because in addition to calcium carbonate, it contains impurities that give color. Similarly, glass products come in different colors, which depend on which dye is added to the glass. The composition of the rubber material for making car tires includes 24 components, the most important of which is Chemical substance rubber.

So it turns out that there are very few pure substances in nature, in technology, in everyday life. Much more common are mixtures - a combination of two or more substances. Air is a mixture of various gases; oil - natural mixture organic matter(hydrocarbons); any minerals, rocks are also solid mixtures of various substances.

The mixtures used in everyday life include, for example, washing powder, culinary mixtures for baking pancakes or cakes, building mixtures, which are heterogeneous mixtures. (Slide 7)

Sometimes the particles of the components in mixtures are very small, indistinguishable to the eye. (Slide 8). For example, flour contains grains of starch and protein that cannot be distinguished with the naked eye. Milk is also a water mixture that contains small droplets of fat, protein, lactose and other substances. You can see fat droplets in milk if you look at a drop of milk under a microscope. These mixtures naturally belong to what? Correctly! These are also heterogeneous mixtures.

The aggregate state of substances in a mixture can be different. Toothpaste, for example, it is a mixture of solid and liquid components.

A mixture of any gases is always homogeneous. For example, clean air is a homogeneous mixture of nitrogen, oxygen, carbon dioxide and noble gases, water vapor. But dusty air is already a heterogeneous mixture of the same gases, only containing more dust particles. You have probably seen more than once how early in the morning the sun's rays break through the loosely drawn curtains into the room. (Slide 9). Their paths are often marked by luminous paths: these are particles of dust suspended in the air that scatter sunlight. (Slide 10). Smog over a city or over an industrial enterprise is also a heterogeneous mixture: air, which contains not only dust particles, but also soot from smoke, droplets of various liquids, etc.

VGeneralization and systematization of knowledge.

The class is divided into groups (3-6) depending on the number of students.

Each group is given theoretical material to study a specific issue.

Questions to study in groups:

Gaseous mixtures in nature and everyday life.

Liquid natural mixtures and liquid mixtures used in everyday life.

Solid mixtures in nature and everyday life.

Handout material with theoretical information.

Gaseous mixtures in nature and everyday life.

Exercise:

What gaseous mixtures are found in nature and are used in everyday life?

What is their composition?

Does natural gas smell?

Why does household gas smell?

What safety regulations do you have to follow when using gas in your home?

Natural gas, associated petroleum gas are also natural mixtures of gaseous substances, the main component of which is methane CH 4 . The same methane enters our apartments through pipelines and burns in the kitchen with a cheerful blue flame. But household gas is also a mixture. Pungently smelling substances are specially introduced into its composition so that you can smell the slightest gas leak by smell. What is it for? The fact is that both air (necessary for the breathing of all living things) and natural gas (an indispensable fuel and raw material for the chemical industry) are a great boon for mankind, but their mixture turns into a formidable destructive force due to extreme explosiveness. From media reports, you certainly know about the tragedies associated with methane explosions in coal mines, household gas explosions as a result of criminal negligence or non-compliance with basic safety standards. If you smell gas in the apartment or in the entrance of your house, you should immediately turn off the taps and valves, ventilate the room, call a specialized emergency service by calling 104. In this case, it is strictly forbidden to use open fire, turn on or turn off electrical appliances.

Liquid mixtures in nature and everyday life.

Exercise:

Read the information below and answer the questions.

What liquid mixtures are found in nature and are used in everyday life?

What is the most common liquid mixture on earth?

Why can't you drink unboiled tap water?

How can you make tap water suitable for cooking?

Oil is a liquid natural mixture. It contains hundreds of different components, mainly carbon compounds. Oil is called the "blood of the Earth", "black gold", and you are well aware of the significant role in the economy of our state and many other countries played by the extraction, processing and export of oil and oil products.

Of course, the most common liquid mixture, or rather a solution, is the water of the seas and oceans. You already know that one liter of sea water contains on average 35 g of salts, most of which are sodium chloride. Unlike clean water marine has a bitter-salty taste, freezes not at 0 ° C, but at -1.9 ° C.

You come across liquid mixtures in everyday life all the time. Shampoos and drinks, potions and household chemicals are all mixtures of substances. Even tap water cannot be considered a pure substance: it contains dissolved salts, the smallest insoluble impurities, it is disinfected by chlorination. Such water cannot be drunk unboiled, it is not recommended to use it for cooking. Special household filters will help to purify tap water not only from solid particles, but also from some dissolved impurities. Even reagent solutions tap water you can't cook. Water for this is purified by distillation, which you will learn about a little later.

Solid mixtures in nature and everyday life.

What solid mixtures are found in nature and are used in everyday life?

Why is coal called "black gold"?

How is coal used?

Solid mixtures are also widespread. As we have said, rocks are mixtures of several substances. Soil, clay, sand are also mixtures. Solid mixtures include glass, ceramics, alloys. Everyone is familiar with cooking mixtures or mixtures that form laundry detergents.

Coal - solid combustible mineral of plant origin solid mixture with a high carbon content (75-97 percent, the rest is impurities). Coal - the main wealth of the Donetsk basin, is represented by various grades from long-flame and coking to gas, fat and anthracites. He gives life to many industrial enterprises and transport, thermal power plants, is the most important energy source, the most valuable raw material for the chemical and coke-chemical industries. Fertilizers, plastics, paints, liquid and gaseous fuels, aromatic substances, medicines are made from coal. Coal is therefore called "black gold".

Natural solid mixtures also include ores (minerals from which metals are obtained): iron, mercury, nepheline, polymetallic, copper ores, etc.

(Representatives of the groups tell the class about the results of their work.)

VISummary of the lesson.

Today we have considered the concepts of "pure substances" and "mixtures". We found out into which groups the mixtures are divided. We learned which mixtures are found in nature, and which are used in everyday life. Ratings today are: ......

VIIHomework message.

You need to learn the reference notes for this lesson.

>> Pure substances and mixtures. Settling. Separation of a mixture of three solids

Pure substances and mixtures

The paragraph will help you:

> realize that absolutely pure substances do not exist;
> distinguish between homogeneous and inhomogeneous mixtures of substances;
> find out in which mixtures the physical properties of the components are preserved, and in which they are not;
> select separation method mixtures of substances depending on its type.

Pure substances and mixtures.

Each substance always contains a certain amount of impurities. A substance that contains almost no impurities is called pure. With these substances work in the scientific laboratory, school chemistry room. Note that absolutely pure substances do not exist.

Each substance contained in a mixture is called a component.

Mixtures in which components cannot be detected by observation are called homogeneous.

Most metal alloys are also homogeneous mixtures. For example, in an alloy of gold and copper (it is used to make jewelry) are missing red copper particles and yellow gold particles.

From materials that are homogeneous mixtures of substances, many items for various purposes are made (Fig. 27).

All mixtures belong to homogeneous mixtures. gases, including air. There are many homogeneous mixtures of liquids.

Rice. 27. Items made from homogeneous mixtures

Such a mixture is formed by mixing, for example, alcohol and water.

Give an example of a homogeneous mixture.

Homogeneous mixtures are also called solutions, even if they are solid or gaseous.

For some physical properties homogeneous mixtures differ from their components. Thus, an alloy of tin and lead used for soldering melts at a lower temperature than pure metals. Water boils at 100°C and water solution salt - with more high temperature. If water is cooled to 0°C, it will begin to turn into ice. A salt solution under these conditions remains a liquid (it freezes at temperatures below 0 °C). This can be seen in winter, when roads and pavements covered with ice are sprinkled with a mixture of salt and sand. Ice melts under the influence of salt; an aqueous solution of salt is formed, which does not freeze in mild frost. And sand is needed so that the road is not slippery.

Rice. 28. Heterogeneous mixture of chalk and water

You know that chalk does not dissolve in water. If its powder is poured into a glass of water, then chalk particles can always be found in the resulting mixture, which are visible to the naked eye or through a microscope (Fig. 28).

Mixtures in which components can be detected by observation are called heterogeneous.

Heterogeneous mixtures (Fig. 29) include most minerals, soil, Construction Materials, living tissues, cloudy water, milk and other foodstuffs, some medicines and cosmetics.

Give an example of an inhomogeneous mixture.

In a heterogeneous mixture, the physical properties of the components are preserved. So, iron filings, mixed with copper or aluminum, do not lose their ability to be attracted to a magnet.

Rice. 29. Heterogeneous mixtures:
a - a mixture of water and sulfur;
b - a mixture of vegetable oil and water;
c - a mixture of air and water

Water mixed with sand, chalk or clay freezes at 0°C and boils at 100°C.

Some types of heterogeneous mixtures have special names: foam (e.g. styrofoam, soap suds), suspension (mixture of water with a small amount of flour), emulsion (milk, well shaken vegetable oil with water), aerosol (smoke, fog).

What are the ingredients in each named mixture?

The material presented above is summarized in Scheme 3.

Scheme 3. Substances and mixtures

It often becomes necessary to separate a mixture in order to obtain its components or to purify a substance from impurities.

There are many methods for separating mixtures. They are chosen taking into account the type of mixture, state of aggregation and differences in the physical properties of the components (Scheme 4). Some methods you know from the course of natural history.

Scheme 4. Methods for separating mixtures

Explain what properties of the components make it possible to separate each heterogeneous mixture indicated in the diagram.

Rice. 30. Worker in a respirator

Consider how some methods separation of mixtures.

The filtering process underlies the operation of a respirator, a device that protects the lungs of a person working in a heavily dusty environment. The respirator has filters that prevent dust from entering the lungs (Fig. 30). The simplest respirator is a bandage made of several layers of gauze. A filter that extracts dust from the air is also in the vacuum cleaner.

With the help of a magnet in industry, iron ore is enriched - magnetite.

Due to the ability to be attracted to a magnet, the ore is separated from sand, clay, earth, etc. In this way, iron is extracted from industrial and domestic waste.

An important method for separating homogeneous mixtures of liquids is distillation, or distillation. This method allows you to clear natural water from impurities. The resulting pure (distilled) water is used in research laboratories, in the production of substances for modern technology, in medicine for the preparation of medicines.

1 The term comes from the Latin word distillatio - dripping.

In industry, the distillation of oil (a mixture of many substances, mainly liquids) produces gasoline, kerosene, and diesel fuel.

In the laboratory, distillation is carried out on a special installation (Fig. 31). When a mixture of liquids is heated, the substance with the lowest boiling point boils first. Its vapor leaves the vessel, cools, condenses1, and the resulting liquid flows into the receiver. When this substance is no longer in the mixture, the temperature will begin to rise, and over time, another liquid component will boil. Non-volatile liquids remain in the vessel.

Rice. 31.Laboratory installation for distillation:

a - ordinary;
1 - a mixture of liquids with different boiling points;
2 - thermometer;
3 - water cooler;
4 - receiver
6 - simplified

The separation of various mixtures also occurs in nature. Dust particles settle from the air, and during rain and snow - water droplets, snowflakes. As a result of settling, cloudy water becomes transparent. Water is also purified from insoluble substances when passing through sand. After the evaporation of water, salts remain on the banks of the estuaries, which were dissolved in it. Dissolved gases are released from the water flowing from the well.

1 The term comes from the Latin word condensatio - thickening, compaction.

conclusions

Every substance contains impurities. A substance is considered pure if it contains almost no impurities.

Mixtures of substances are either homogeneous or heterogeneous. In a homogeneous mixture, the components cannot be detected by observation, but in an inhomogeneous mixture it is possible.

Some physical properties of a homogeneous mixture differ from those of the components. In a heterogeneous mixture, the properties of the components are preserved.

Inhomogeneous mixtures of substances are separated by settling, filtering, sometimes by the action of a magnet, and homogeneous mixtures are separated by evaporation and distillation (distillation).

?
29. What types of mixtures are there and how do they differ?

30. Write down the given words and phrases in the appropriate columns of the table below: aluminum, ash, newsprint, mercury, air, iodine tincture, granite, ice from pure water, carbon dioxide, reinforced concrete.

31. Name a few foods that are solutions.

32. What popular drink, depending on the method of preparation, is a homogeneous or heterogeneous mixture?

33. Can an aqueous solution of table salt be turned into a heterogeneous mixture? If possible, how to do it?

34. What mixtures can be separated by filtration: a) a mixture of sand and clay; b) a mixture of alcohol and copper filings; c) a mixture of water and gasoline; d) a mixture of water with pieces of plastic? Name the substances that will remain on the filter.

35. How would you separate the mixture of: a) table salt and chalk; b) alcohol and water? What differences in the properties of substances make it possible to use the method you have chosen?

36. Consider an experiment to separate a mixture of table salt, sand, iron and sawdust. Make a plan for it, briefly describe each stage of the experiment and talk about the expected results.

Experimenting at home

settling

Pour water into two glasses. Pour 1/2 teaspoon of sand into one glass, and the same amount of starch into another. Stir both mixtures at the same time. Do particles of matter settle in water at the same rate? If not, which particles settle faster and why?

Write down your observations in a notebook.

Separation of a mixture of three solids

Mix small amounts of crushed styrofoam, sand and table salt.

What methods can be used to separate this mixture?

Divide mixture 1 . If heating is necessary, use it very carefully.

Describe each step of the experiment in your notebook.

Popel P. P., Kriklya L. S., Chemistry: Pdruch. for 7 cells. zahalnosvit. navch. zakl. - K .: Exhibition Center "Academy", 2008. - 136 p.: il.

In the mixture, the starting substances are included unchanged. In this case, often the original substances become unrecognizable, because the mixture exhibits different physical properties compared to each isolated starting substance. When mixed, however, no new substance is produced.

The specific qualities of a mixture, such as density, boiling point or color, depend on the mixture ratio (mass ratio). A mixture of two metals obtained by mixing their melts is called an alloy. In another connection, one speaks of a conglomerate. Colloidal solutions are in the middle between homogeneous and heterogeneous mixtures. These liquids are mixed with solid particles, each of which consists of a small number of molecules. Therefore, such a mixture behaves like a solution.

If they want to separate a mixture into pure substances, then some physical properties are used. This results in the selection of an appropriate separation method.

Homogeneous and heterogeneous mixtures

Various types of mixtures can be classified into 2 groups:

• Heterogeneous mixtures are not completely mixed, since pure substances exist in clearly delimited phases, that is, they are multiphase materials.
• Homogeneous mixtures are mixed pure substances at the molecular level, that is, they are single-phase materials.

Homogeneous mixtures are divided according to their state of aggregation into three groups:

• gas mixtures;
• solutions;
• solid solutions.

Heterogeneous mixtures of two substances can be divided according to their state of aggregation into the following groups:

A measure indicating the proportion of substances in a mixture is concentration.

The difference between pure substances and mixtures

The simplest such distinction is for gases. A pure complex substance (for example, water) consists of one type of molecules, and a mixture of gases consists of several types (for example, oxygen and hydrogen molecules). A mixture of gases can be separated by physical methods (for example, diffusion), but a complex substance cannot.

With regard to liquid and solid mixtures, everything is not always clear.

Separation of mixtures

There are various methods for separating mixtures. For gases, these methods are based on the difference in velocities or masses of the molecules of the substances included in the mixture.

1. The main methods for isolating substances from a heterogeneous (heterogeneous) mixture:

• upholding

• filtration

• magnet action

2. The main methods for isolating substances from a homogeneous (homogeneous) mixture:

• evaporation

• crystallization

• distillation

• chromatography

see also

Notes

Wikimedia Foundation. 2010 .

See what "Mixture (chemistry)" is in other dictionaries:

Mixture: A mixture (chemistry) is a product of mixing, a mechanical combination of any substances, characterized by an impurity content above a certain limit. For example: combustible mixture, helium-oxygen mixture. Random, disorderly, deprived ... ... Wikipedia

Ash and slag mixture- Ash and slag mixture - a mixture consisting of ash and slag formed at thermal power plants when coal is burned in boiler furnaces. [GOST 25137 82] Ash and slag mixture - a mechanical mixture of dusty fly ash and slag ... ...

- (Eschka mixture) a mixture of two parts of MgO and one part of Na2CO3, a reagent that absorbs sulfur and chlorine oxides well. For example, to determine the sulfur content of coal, a sample of coal is burned with an Eschka mixture. In this case, soluble sulfates are formed ... ... Wikipedia

Mixture activated sfb- - a mixture prepared on water with additives, passed through a rotary pulsation apparatus and subject to cavitation; allows you to get an economic effect by increasing the specific surface of cement and the formation of cement ... ... Encyclopedia of terms, definitions and explanations of building materials

Asphalt mix- - a rationally selected mixture of mineral materials [crushed stone (gravel) and sand with or without mineral powder] with bitumen, taken in certain proportions and mixed in a heated state. [GOST 9128 97] Heading term: Asphalt ... ... Encyclopedia of terms, definitions and explanations of building materials

Mix concrete of a given quality- - this is concrete mix, the required properties and additional characteristics of which are specified by the manufacturer, who is responsible for providing these required properties and additional characteristics. [GOST 7473 2010] Term heading: ... ... Encyclopedia of terms, definitions and explanations of building materials

Concrete mix of specified normalized composition- is a concrete mixture of a given composition, the composition of which is determined by a standard or other technical document such as production standards. [GOST 7473 2010] Term heading: Concrete properties Encyclopedia headings: Abrasive ... ... Encyclopedia of terms, definitions and explanations of building materials

Mix concrete of a given composition- is a concrete mixture, the composition of which and the components used in the preparation are specified by the manufacturer, who is responsible for ensuring this composition. [GOST 7473 2010] Term heading: Concrete properties Encyclopedia headings: ... ... Encyclopedia of terms, definitions and explanations of building materials

Refractory concrete mix- - a refractory mixture consisting of refractory powders and refractory cement, ready for use after the introduction of the liquid. [GOST R 52918 2008] Term heading: Concreting technologies Encyclopedia headings: Abrasive equipment, ... ... Encyclopedia of terms, definitions and explanations of building materials

Refractory mixture- - unshaped refractory, consisting of refractory powders, ready for use after the introduction of the binder. [GOST R 52918 2008] Refractory mixture - unshaped refractories consisting of refractory powders requiring the introduction of a binder. [GOST ... Encyclopedia of terms, definitions and explanations of building materials

Books

• Fundamentals of general and physical chemistry. Textbook, Eremin Vadim Vladimirovich, Borshchevsky Andrey Yakovlevich. The book is created on the basis of a one-year course `General and Physical Chemistry` for 2nd year students of the Faculty of Physics of Moscow State University. Choosing the level of presentation, we proceeded from the fact that it will be read ...