For oxygen production, you will need substances that are rich in them. These are peroxides, nitrate, chlorates. We will use those that can be easily obtained.
There are several ways to get oxygen at home, let's sort them out in order.
The simplest and affordable way obtaining oxygen - use potassium permanganate (or more correct name- potassium permanganate). Everyone knows that potassium permanganate is an excellent antiseptic, used as a disinfectant. If not, you can get it at the pharmacy.
Let's do this. Pour a little potassium permanganate into the test tube, close it with a test tube with a hole, install a gas outlet tube in the hole (oxygen will flow through it). We place the other end of the tube in another test tube (it should be placed upside down, since the released oxygen is lighter than air and will rise upward. Using the same cork, close the second test tube.
As a result, we should have two test tubes connected by a gas outlet pipe through the plugs. One (not inverted) test tube contains potassium permanganate. We will heat the test tube with potassium permanganate. The dark violet-cherry color of the potassium permanganate crystals will disappear and turn into dark green crystals of potassium manganate.
The reaction proceeds like this:
2KMnO 4 → MnO 2 + K 2 MnO 4 + O 2
So from 10 grams of potassium permanganate, you can get almost 1 liter of oxygen. After a couple of minutes, you can remove the potassium permanganate flask from the flame. We got oxygen in an inverted tube. We can check it. To do this, carefully disconnect the second tube (with oxygen) from the gas outlet tube, covering the hole with your finger. Now, if you bring a weakly burning match into a flask with oxygen, then it will flash brightly!
Oxygen production it is also possible with the help of sodium or potassium nitrate (the corresponding sodium and potassium salts of nitric acid).
(Potassium and sodium nitrates - they are also saltpeters, are sold at fertilizer stores).
So, to obtain oxygen from nitrate, take a test tube made of refractory glass on a tripod, put nitrate powder there (5 grams will be enough). You will need to put a ceramic cup with sand under the test tube, as glass can melt from temperature and flow. Consequently, the burner will need to be held slightly to the side, and the tube with saltpeter should be tilted.
With strong heating of nitrate, it begins to melt, while oxygen is released. The reaction goes like this:
2KNO 3 → 2KNO 2 + O 2
The resulting substance is potassium nitrite (or sodium, depending on which nitrate is used) - a salt of nitrous acid.
Another way oxygen production- use hydrogen peroxide. Peroxide, hydroperite - all the same substance. Hydrogen peroxide is sold in tablets and solutions (3%, 5%, 10%), which can be purchased at the pharmacy.
Unlike the previous substances, saltpeter or potassium permanganate, hydrogen peroxide is an unstable substance. Already in the presence of light, it begins to decompose into oxygen and water. Therefore, in pharmacies, peroxide is sold in dark glass bottles.
In addition, catalysts such as manganese oxide contribute to the rapid decomposition of hydrogen peroxide into water and oxygen. Activated carbon, steel powder (fine shavings) and even saliva. Therefore, you do not need to heat hydrogen peroxide, a catalyst is enough!
Hello .. Today I will tell you about oxygen and how to obtain it. I remind you that if you have any questions for me, you can write them in the comments to the article. If you need any help with chemistry,. I will be glad to help you.
Oxygen is common in nature in the form of isotopes 16 O, 17 O, 18 O, which have the following percentage on Earth - 99.76%, 0.048%, 0.192%, respectively.
In a free state, oxygen is in the form of three allo-tropic modifications : atomic oxygen - O o, dioxygen - O 2 and ozone - O 3. Moreover, atomic oxygen can be obtained as follows:
КClO 3 = KCl + 3O 0
KNO 3 = KNO 2 + O 0
Oxygen is found in over 1400 different minerals and organic matter, in the atmosphere its content is 21% by volume. And in human body contains up to 65% oxygen. Oxygen is a colorless and odorless gas, slightly soluble in water (3 volumes of oxygen dissolve in 100 volumes of water at 20 ° C).
In the laboratory, oxygen is obtained by moderate heating of certain substances:
1) When decomposing manganese compounds (+7) and (+4):
2KMnO 4 → K 2 MnO 4 + MnO 2 + O 2
permanganate manganate
potassium potassium
2MnO 2 → 2MnO + O 2
2) When decomposing perchlorates:
2KClO 4 → KClO 2 + KCl + 3O 2
perchlorate
potassium
3) When decomposing berthollet's salt (potassium chlorate).
In this case, atomic oxygen is formed:
2KClO 3 → 2 KCl + 6O 0
chlorate
potassium
4) Upon decomposition in the light of salts of hypochlorous acid- hypochlorites:
2NaClO → 2NaCl + O 2
Ca (ClO) 2 → CaCl 2 + O 2
5) When heating nitrates.
This produces atomic oxygen. Depending on the position of the nitrate metal in the line of activity, various reaction products are formed:
2NaNO 3 → 2NaNO 2 + O 2
Ca (NO 3) 2 → CaO + 2NO 2 + O 2
2AgNO 3 → 2 Ag + 2NO 2 + O 2
6) When decomposing peroxides:
2H 2 O 2 ↔ 2H 2 O + O 2
7) When heating oxides of inactive metals:
2Аg 2 O ↔ 4Аg + O 2
This process is relevant in everyday life. The fact is that dishes made of copper or silver, having a natural layer of oxide film, when heated, form active oxygen, which is an antibacterial effect. Dissolution of salts of inactive metals, especially nitrates, also leads to the formation of oxygen. For example, the total dissolution of silver nitrate can be represented in stages:
AgNO 3 + H 2 O → AgOH + HNO 3
2AgOH → Ag 2 O + O 2
2Ag 2 O → 4Ag + O 2
or in summary:
4AgNO 3 + 2H 2 O → 4Ag + 4HNO 3 + 7O 2
8) When heating chromium salts the highest degree oxidation:
4K 2 Cr 2 O 7 → 4K 2 CrO 4 + 2Cr 2 O 3 + 3 O 2
dichromate chromate
potassium potassium
In industry, oxygen is obtained:
1) Electrolytic decomposition of water:
2H 2 O → 2H 2 + O 2
2) Interaction of carbon dioxide with peroxides:
СО 2 + К 2 О 2 → К 2 СО 3 + О 2
This method is an irreplaceable technical solution breathing problems in isolated systems: submarines, mines, spacecraft.
3) When ozone interacts with reducing agents:
О 3 + 2КJ + H 2 O → J 2 + 2KOH + O 2
Oxygen production is of particular importance in the process of photosynthesis. occurring in plants. All life on Earth depends fundamentally on this process. Photosynthesis is a complex multistep process. It starts with light. Photosynthesis itself consists of two phases: light and dark. V light phase the pigment chlorophyll, contained in the leaves of plants, forms the so-called "light-absorbing" complex ", which takes away electrons from the water, and thus splits it into hydrogen and oxygen ions:
2H 2 O = 4e + 4H + O 2
The accumulated protons contribute to the synthesis of ATP:
ADP + F = ATP
In the dark phase, carbon dioxide and water are converted into glucose. And oxygen is released as a side:
6CO 2 + 6H 2 O = C 6 H 12 O 6 + O 2
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Oxygen is one of the gases most used by mankind; it is widely used in almost all areas of our life. Metallurgy, chemical industry, medicine, economy, aviation - that's just short list spheres where you cannot do without this substance.
Oxygen production is carried out in accordance with two technologies: laboratory and industrial. The first methods for the production of colorless gas were based on chemical reactions. Oxygen is produced by the decomposition of potassium permanganate, berthollet's salt or hydrogen peroxide in the presence of a catalyst. but laboratory techniques cannot fully satisfy the needs for this unique chemical element.
The second way to obtain oxygen is cryogenic rectification, either using adsorption or membrane technology... The first method provides high purity of the separation products, but has a longer (compared to the second methods) start-up period.
Oxygen adsorption units have proven themselves to be among the best high-performance systems for the production of oxygen-enriched air. They make it possible to obtain colorless gas with a purity of up to 95% (up to 99% with the use of an additional purification stage). Their use is justified in economically especially in situations where there is no need for high-purity oxygen, for which you would have to pay extra.
Main characteristics of cryogenic systems
Are you interested in the production of oxygen with a purity of up to 99.9%? Then pay attention to installations based on cryogenic technology. Advantages of high purity oxygen production systems:
- long service life of the installation;
- high performance;
- the ability to obtain oxygen with a purity of 95 to 99.9%.
But due to the large dimensions of cryogenic systems, the inability to quickly start and stop, and other factors, the use of cryogenic equipment is far from always advisable.
The principle of operation of adsorption plants
The scheme of operation of oxygen systems using adsorption technology can be represented as follows:
- compressed air moves into the receiver, into the air preparation system to get rid of mechanical impurities and filtration from droplet moisture;
- the purified air is directed to the adsorption air separation unit, which includes adsorbers with an adsorbent;
- during operation, adsorbers are in two states - absorption and regeneration; at the stage of absorption, oxygen enters the oxygen receiver, and nitrogen at the stage of generation is discharged into the atmosphere; after which oxygen is sent to the consumer;
- if necessary, the gas pressure can be increased using an oxygen booster compressor with subsequent filling into cylinders.
Adsorption complexes are distinguished by a high level of reliability, full automation, ease of maintenance, small dimensions and weight.
Advantages of gas separation systems
Plants and stations using adsorption technology for the production of oxygen are widely used in the most different areas: when welding and cutting metals, in construction, fish farming, growing mussels, shrimps, etc.
The advantages of gas separation systems:
- the ability to automate the oxygen production process;
- no special requirements for the premises;
- quick start and stop;
- high reliability;
- low cost of the produced oxygen.
Advantages of adsorption plants NPK Grasys
Are you interested in the production of oxygen in an industrial way? Would you like to receive oxygen at the lowest financial cost? Research and Production Company "Grasys" will help to solve your problem at the very high level... We offer reliable and efficient systems to obtain oxygen from the air. Here are the main distinctive features of our products:
- full automation;
- thought out to the smallest detail designs;
- modern systems control and management.
The oxygen produced by our air separation adsorption units is up to 95% pure (with optional up to 99% post-treatment). Gas with such characteristics is widely used in metallurgy when welding and cutting metals, in national economy... The equipment we manufacture uses modern technologies that provide unique opportunities in the field of gas separation.
Features of our adsorption oxygen plants:
- high reliability;
- low cost of the produced oxygen;
- innovative highly intelligent control and management system;
- ease of maintenance;
- the ability to produce oxygen with a purity of up to 95% (with the option of additional purification up to 99%);
- productivity is up to 6000 m³ / h.
Adsorption oxygen plants NPK "Grasys" - unique combination world design experience in the production of gas separation equipment and domestic innovative technologies.
The main reasons for cooperation with NPK Grasys
The industrial method for producing oxygen using installations based on adsorption technology is one of the most promising today. It allows you to obtain a colorless gas with minimum energy consumption of the required purity. A substance with these parameters is in demand in metallurgy, mechanical engineering, the chemical industry, and medicine.
Cryogenic rectification method - optimal solution when it is necessary to produce oxygen of high purity (up to 99.9%).
The leading domestic company "Grasys" offers highly efficient systems for the production of oxygen using adsorption technology on favorable terms... We have extensive experience in the implementation of various turnkey projects, so we are not afraid of even the most difficult tasks.
Advantages of working with a responsible supplier of equipment NPK Grasys:
- our company is a direct manufacturer, therefore, the cost of the installed installations does not increase the additional commissions of intermediaries;
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- Individual approach to each client;
- many years of experience in the field of oxygen production.
Call our managers to clarify the nuances of cooperation.
In more detail, you can familiarize yourself with oxygen equipment (oxygen generators, oxygen plants, oxygen stations) on the page
In lesson 17 “ Oxygen production"From the course" Chemistry for dummies»Find out how oxygen is obtained in laboratory conditions; we will learn what a catalyst is and how plants affect the production of oxygen on our planet.
The most important air substance for humans and other living organisms is oxygen. Oxygen is used in large quantities in industry, so it is important to know how you can get it.
In a chemical laboratory, oxygen can be obtained by heating some complex substances, which include oxygen atoms. These substances include the substance KMnO 4, which is in your home first aid kit called "potassium permanganate".
You are familiar with the simplest devices for producing gases. If you put a little KMnO 4 powder in one of these devices and heat it, then oxygen will be released (Fig. 76):
Oxygen can also be produced by the decomposition of hydrogen peroxide H 2 O 2. To do this, a very small amount of a special substance should be added to the test tube with H 2 O 2 - catalyst- and close the test tube with a stopper with a gas outlet tube (Fig. 77).
For this reaction, the catalyst is a substance whose formula is MnO 2. In this case, the following chemical reaction occurs:
Note that there is no catalyst formula on either the left or right sides of the equation. Its formula is usually written in the reaction equation over the equal sign. What is the catalyst added for? The decomposition of H 2 O 2 at indoor conditions proceeds very slowly. Therefore, it takes a long time to obtain appreciable amounts of oxygen. However, this reaction can be dramatically accelerated by the addition of a catalyst.
Catalyst is a substance that accelerates a chemical reaction, but is not consumed in it.
Precisely because the catalyst is not consumed in the reaction, we do not write its formula in any part of the reaction equation.
Another way to obtain oxygen is the decomposition of water under the influence of constant electric current... This process is called electrolysis water. Oxygen can be obtained in the device schematically shown in Figure 78.
In this case, the following chemical reaction occurs:
Oxygen in nature
A huge amount of gaseous oxygen is found in the atmosphere, dissolved in the waters of the seas and oceans. Oxygen is essential for all living organisms to breathe. Without oxygen, it would be impossible to obtain energy through combustion different types fuel. These needs annually consume about 2% of atmospheric oxygen.
Where does oxygen come from on Earth and why does its amount remain approximately constant, despite such a consumption? The only source of oxygen on our planet are green plants that produce it under the influence of sunlight in the process of photosynthesis. This is a very complex process with many stages. As a result of photosynthesis in green parts of plants carbon dioxide and water is converted to glucose C 6 H 12 O 6 and oxygen. Total
the equation of reactions occurring in the process of photosynthesis can be represented as follows:
It was found that about one tenth (11%) of the oxygen produced by green plants is provided by terrestrial plants, and the remaining nine tenths (89%) are provided by aquatic plants.
Obtaining oxygen and nitrogen from the air
The huge reserves of oxygen in the atmosphere make it possible to obtain and use it in various industries. V industrial conditions oxygen, nitrogen and some other gases (argon, neon) are obtained from the air.
To do this, air is first converted into a liquid (Fig. 79) by cooling to such a low temperature, at which all its components pass into a liquid state of aggregation.
Then this liquid is slowly heated, as a result of which sequential boiling off occurs at different temperatures (i.e., a transition to gaseous state) substances contained in the air. By collecting gases boiling away at different temperatures, nitrogen, oxygen and other substances are obtained separately.
Lesson summary:
- In laboratory conditions, oxygen is obtained by the decomposition of some complex substances, which include oxygen atoms.
- Catalyst - a substance that accelerates the flow chemical reaction, but it itself is not consumed.
- The source of oxygen on our planet is green plants, in which the process of photosynthesis takes place.
- In industry, oxygen is obtained from air.
Hopefully lesson 17 " Oxygen production"Was understandable and informative. If you have any questions, write them in the comments.
This lesson is about learning modern ways obtaining oxygen. You will learn by what methods and from what substances oxygen is obtained in the laboratory and industry.
Topic: Substances and their transformations
Lesson:Oxygen production
For industrial purposes, oxygen must be obtained in large volumes and in the cheapest possible way. This method of obtaining oxygen was proposed by the laureate Nobel Prize Peter Leonidovich Kapitsa. He invented an air liquefaction plant. As you know, the air contains about 21% by volume of oxygen. Oxygen can be separated from liquid air by distillation, because all substances that make up the air have different temperatures boiling. The boiling point of oxygen is -183 ° C, and the boiling point of nitrogen is -196 ° C. This means that when distilling liquefied air, nitrogen will first boil and evaporate, and then oxygen.
In the laboratory, oxygen is not required in these large quantities as in the industry. Usually it is brought in blue steel cylinders in which it is under pressure. In some cases, it is still required to obtain oxygen chemically. For this, decomposition reactions are used.
EXPERIENCE 1. Pour a solution of hydrogen peroxide into a Petri dish. At room temperature hydrogen peroxide decomposes slowly (we do not see any signs of the reaction), but this process can be accelerated by adding a few grains of manganese (IV) oxide to the solution. Gas bubbles immediately begin to form around the grains of black oxide. This is oxygen. No matter how long the reaction proceeds, grains of manganese (IV) oxide do not dissolve in the solution. That is, manganese (IV) oxide participates in the reaction, accelerates it, but is not consumed in it.
Substances that accelerate the reaction, but are not consumed in the reaction, are called catalysts.
The reactions accelerated by catalysts are called catalytic.
Acceleration of the reaction as a catalyst is called catalysis.
Thus, manganese (IV) oxide serves as a catalyst in the decomposition of hydrogen peroxide. In the reaction equation, the catalyst formula is written above the equal sign. Let us write down the equation of the reaction carried out. When hydrogen peroxide decomposes, oxygen is released and water is formed. The release of oxygen from solution is shown with an upward arrow:
2. A single collection of digital educational resources ().
3. Electronic version of the journal "Chemistry and Life" ().
Homework
with. 66-67 No. 2 - 5 of Workbook in chemistry: grade 8: to the textbook by P.A. Orzhekovsky and others. "Chemistry. Grade 8 "/ О.V. Ushakova, P.I. Bespalov, P.A. Orzhekovsky; under. ed. prof. P.A. Orzhekovsky - M .: AST: Astrel: Profizdat, 2006.
