Every day, one way or another, we have contact with acids. We will not delve into the study of acids and boring chemical formulas, but will voice a few facts that will certainly be interesting to know.
Fact #1: The first acid discovered by man was acetic acid. Perhaps acetic acid in antiquity would not have been identified if it were not for the predilection of people of the past for wine. If you violate the technology of the winemaking process, then instead of fragrant and tasty wine, you get vinegar. This was very upsetting and frustrating. Ancient people could not find an application for wine vinegar, so they simply poured out the sour product. Only many years later, wine vinegar began to be used as a medicine, seasoning and even a solvent. By the way, the name "acid" itself comes from the Latin word "acetum" - vinegar.
Fact #2: Gastric juice is the real hydrochloric acid. Every day our stomach is forced to renew its surface, which has suffered as a result of exposure to it. gastric juice. You will be surprised now, but the environment in your stomach is so aggressive that if you put a razor blade in it, it will completely dissolve in a week.
Fact #3: Orthophosphoric acid is an important ingredient in Coca Cola. In its field of application, phosphoric acid is simply unique. It is used everywhere, from the food industry to the production of fertilizers. The acidity index of everyone's favorite Coca Cola is pH = 2.8, so putting jewelry into a glass of drink can get rid of plaque and dirt.
Fact #5: Citric acid is not always citric. In order to obtain 25 kg of citric acid, it is necessary to process one ton of lemons. Agree, this is a very expensive pleasure. A man found a loophole here too, so citric acid is often obtained from mold fungus called Aspergillus niger.
Fact #6:"Royal vodka" - a combination of two acids. If connect hydrochloric acid with nitrogen, observing a strict proportion of 1 to 3, then in the end we get a yellow liquid that can dissolve most of the known to us noble metals such as platinum, gold and so on. Therefore, when you hear the prefix "royal" to a strong drink, do not rush to rejoice, because we are talking about the strongest poison.
Modern chemistry is a science that operates a large number reagents. These can be salts, reagents, alkalis. But the most large group- acids. These are complex compounds based on hydrogen. In this case, foreign atoms here can be replaced by metal atoms. Acids are used in various branches of human activity. For example, in medicine, the food industry, in the production of household goods. That is why this group of reagents should be especially carefully studied.
Basic information about nitric acid
This is a strong reagent that belongs to the category of monocomponent acids. It looks like a normal clear liquid. Sometimes there is a yellowish tinge. This is due to the fact that at warm temperature nitric oxide accumulates on the surface. Nitrogen dioxide may also appear as a brown precipitate. But it happens under the sun. When exposed to air, the acid begins to smoke strongly. In addition, it normally reacts with metals. It dissolves perfectly in water, but in the case of ether there are a number of limitations.
What forms of release exist? In total, two are shared - ordinary (concentration 65-68%) and smoky (at least 85%). In this case, the color of the smoke can vary greatly. If the concentration is 86-95%, then it is white. Is the percentage higher? Then you will see red.
Receipt process
Today it does not differ both in the case of strong and weak concentration. It can be divided into several stages.
Crystalline oxidation of synthetic ammonia occurs.
It is necessary to wait until nitrous gases form.
All the water contained in the composition is absorbed.
At the final stage, it is necessary to wait until the acid reaches the required concentration.
How is storage and transportation?
This reagent does not belong to the category of particularly aggressive. Therefore, there are not so many requirements for storage and transportation. It is required to keep the acid in sealed containers made of aluminum or chromium steel. Laboratory glass is also suitable. As for the tanks, they should be marked "Dangerous". The same applies to small containers.
Precautions for use
This chemical reagent belongs to strong acids. It has III hazard class. Those persons who are allowed to work with this substance must receive appropriate instruction. In the room you must be in special clothing. It includes overalls, gloves, respirators, goggles. Individual respiratory and eye protection equipment is required. The consequences of non-compliance with safety requirements can be serious. If the acid gets on the skin, it will cause burns and ulcers. Will you breathe it in? Then you will get very poisoned or even get pulmonary edema. So in the laboratories it is necessary to organize constant monitoring, ask employees to be instructed on safety measures.
Where is nitric acid used?
Due to its chemical properties, this acid is used in many industries. A few should be singled out. First of all, it is industry. With it, you can easily synthesize artificial fibers. In addition, often nitric acid is the main component in the manufacture of motor oil. Surely you know that it is used in metallurgy. With it, you can dissolve and etch metals. There is a special industrial nitric acid that does a better job of solving the problems described.
Application in everyday life
It is used to make products that allow you to effectively clean Jewelry at home. But you need to be extremely careful not to allow these products to come into contact with the skin. With drip irrigation, nitric acid can be used as a cleaner. A concentration of 60% will be enough to get rid of salts or dissolve sediment in a drip system.
What is the application in medicine?
If you look at the composition of some medicines, you will see that they contain nitric acid. For example, 30% is used to fight warts. Also often this component is added to the means to combat peptic ulcers. It is an excellent antiseptic with astringent properties.
Agricultural use
Agronomists need mineral fertilizers in order to make the crop richer. Some of them contain nitric acid. But it is necessary to clearly calculate the dose so that the resulting vegetables and fruits do not cause any harm to health. If there is too much acid, then nitrates will accumulate in the cultures. There are several types of acid-based fertilizers: amide, ammonia, nitrate.
But this reagent has salts, which in agriculture used even more frequently. They are added to some drugs that are given to animals.
What can be said in conclusion?
As you can see, nitric acid is a very important component that is used in a huge number of industries. Without her it would be impossible to imagine modern life. And chemists on a regular basis come up with where else this reagent can be used.
In contact with
Technology and nature
Dirt and anti-dirt
THE STORY OF HOW ACID TARS FROM OIL REFINING WASTE AND AIR POLLUTANTS TURNED INTO ENVIRONMENTAL PROTECTION
Candidate of Chemical Sciences A. I. NEKHAEV
It has been rightly observed: there is no dirt in chemistry; dirt is a substance, most often a mixture of substances, out of place. The history of acid tars, which, unfortunately, are quite massive products of oil refining, is another confirmation of this. Why "unfortunately", you will understand a little later, as well as find out (who does not know) what kind of bird these acid tars are. By no means a blue bird of happiness, rather a black one ...
Let us begin our story with a substance incomparably more popular than all the tars put together. The alchemists called it vitriol oil - we call it sulfuric acid.
WHY A PETROCHEMIST WOULD NEED SULFURIC ACID
This acid is a substance not only extremely popular, but also extremely important. No wonder the volume of its production is one of the indicators of the economic potential of the country.
Most sulfuric acid is now spent on the production of mineral fertilizers, but it is almost as necessary for all other sub-sectors of the chemical industry. And not only chemical: metalworking, textile, leather, food industries cannot do without sulfuric acid. Oil refining and petrochemistry are no exception: they consume sulfuric acid on a fairly large scale and for different purposes. Here are some examples.
The most common synthetic detergents (CMC) are now amine active. This means that their active principle lies in the anion - most often in the anion of the HSO 3 - composition, which came to CMC from sulfuric acid, the cheapest and most accessible. For example, castor oil, under the action of sulfuric acid, is converted from a staining substance into detergent. In our time, in order to obtain high-quality CMC, it is usually not natural, but synthetic raw materials (alkylbenzenes) that are sulfonated, and the cheapest CMC for technical needs have been and are obtained by sulfonation of kerosene and gas oil fractions of oil.
Another example. Approximately one fifth of all petrochemical products are alcohols. The most common method for obtaining alcohols, including ethyl alcohol, is the sulfuric acid hydration of olefins. which again requires sulfuric acid. Another example. A modern car engine designed for high-octane gasoline. The classic antiknock tetraethyl lead becomes persona non grata because it poisons the atmosphere. Nowadays, the octane number of gasoline is being increased by means of alkylation processes. As a result of these processes, branched hydrocarbon molecules are obtained. They are added to gasoline to increase its octane number, and the alkylation catalyst is still the same sulfuric acid ... We will omit for insignificance - the insignificance of the scale of consumption - other cases of using sulfuric acid as a catalyst for petrochemical processes. Incomparably more it is used for the purification of petroleum products: fuels, oils, paraffin. Acid removes unsaturated and aromatic hydrocarbons, resinous substances, sulfur and nitrogen compounds from oil - everything that reduces the stability of fuels and oils during storage, worsens their performance, smell, color. Purification of petroleum products with sulfuric acid is the oldest and technologically the simplest method. But at the same time, this is also a backward method: the losses of valuable oil components are great, the acid corrodes the equipment, and most importantly, a lot of waste is generated, which together are called acid tars. Because of this, sulfuric acid cleaning methods have now been supplanted (but not completely) by more advanced ones, such as hydrotreating fuels or treating oils with selective solvents. About 90% of the world's oil production is now processed in this way. However, let's remember the huge scale of production: thousands of tons of H 2 SO 4 are hidden behind the remaining ten percent. The purification of the most valuable oils - hydraulic, vacuum, electrical insulating - is still trusted only with sulfuric acid.
Thus, the positions of sulfuric acid in oil refining and petrochemistry remain quite strong. And if so, the amount of acid tars continues to grow.
FATE OF WASTE
Black viscous mass, which includes up to 70% H 2 SO 4 plus the original organic compounds, alkyl sulfuric acids and other sulfonation products, plus resins and polymers - all this is acid tars. Their components are partly chemically bonded, partly just mixed together, and it is extremely difficult to separate them.
As you know, the degree of use of production waste is an indicator of the development of the industry, a measure of the culture of production. Utilization of acid tars until recently was considered a hopeless business. It is impossible to dump these wastes into rivers even after careful neutralization: they decompose slowly and for a long time. The easiest way is to burn the ill-fated acid tar, having previously dissolved it, say, in boiler fuel. But this is not a solution either: flue gases with a significant content of SO 2 are formed, and in this case the effect of acid tars on the biosphere will be very negative.
That is why for many decades acid tars were poured into huge storage ponds. Needless to say, both these ponds themselves and their immediate surroundings are lifeless. “Even a bird does not fly to it, and an animal does not, only a black whirlwind ...” the pungent smell of sulfur dioxide mixed with no less “aromatic” organic matter spreads far. This is gradually decomposing acid tars in storage ponds.
It was impossible to put up with either the irretrievable loss of acid and organic matter, much less pollution environment. Sulfuric acid has successfully purified many products for many years. Now the question arose. to purify it itself and at the same time receive income from waste.
A natural move: in order to somehow utilize acid tars, you must first of all divide them into at least two main components - organic matter and sulfuric acid. The simplest tool for such a separation can be water vapor. The mixture processed by him is stratified. The top layer is organic with traces of acid, the bottom is black dilute acid. The spent acid can either be concentrated or used where a weak acid can handle it, such as in the production of ammonium sulphate or superphosphate, in the leather industry, or for the demineralization of saline soils.
The choice is relatively small, especially since each of the listed industries prefers at least technically pure acid ... There is more demand for concentrated H 2 SO 4, but it is not easy to remove excess water from the acid. The productivity is low, the equipment corrodes, and most importantly, it is necessary to first remove the remains of organic substances, which, when evaporated, decompose up to 40% of the acid. So it turns out that the game is not worth the candle.
But there is no evil without good. Thermal decomposition of the dirty acid proved to be a profitable option. Sulfuric acid splits, "in order to die, be embodied" in the same sulfuric acid. The decomposition product - sulfur dioxide - is needed both for the isolation of cellulose from wood chips, and as a preservative agent during the storage of fruits, and - most importantly - SO 2 is used to produce sulfuric acid. Strong, clean, suitable for any business.
But what is the second component of acid tars - black "viscous" organic matter good for? It could be burned as boiler fuel. But it will be bad fuel: there is quite a lot of sulfur in it, besides, nozzles quickly coke. It is possible to process the organic part of the acid tar with air when heated and thereby turn it into bitumen. Bitumen was the first oil product to fall into the hands of man (as early as 3800 BC!). Since ancient times, in construction, medicine and in the mummification of corpses, its water resistance, astringent and antiseptic properties have been used. Today, huge masses of bitumen are used to build buildings and roads, to protect metal structures from corrosion. Demand for bitumen exceeds supply. Getting it from acid tar is twice useful: the most harmful dirt turns into the right product ...
Journal "Chemistry and Life" No. 10, 1978.
Belongs to monobasic preparations of weak action. It is characterized by the absence of color and a pungent odor. The drug is hygroscopic, characterized by the ability to react with many types of solvents and combines well with organic substances and gases. When interacting with active metals, it forms salts, and when the temperature drops to -16 ° C, it turns into a crystalline mass.
Ways and methods of obtaining
An industrial way to create acetic acid is the use of catalysts in the oxygen oxidation of acetaldehyde. The process takes place at high pressure and temperature. Depending on the technology, manganese, rhodium or cobalt catalysts can be used. For the food industry in the production of acetic acid, a biocatalytic method is used using enzymes of acetic acid bacteria and liquids containing ethanol.
The substance was discovered in ancient times due to the violation of winemaking technology. The vinegar formed in sour wine was found to be used in everyday life, and the acid began to be used as a seasoning for food, a medicine and an organic solvent.
Interesting historical facts related to organic acids: In 1714, by decree of Peter I, an apothecary garden was founded in St. Petersburg. There they grew medicinal plants supplying pharmacies with them or processing them into medicines. So, the leaves of one of these plants, placed in milk, protect it from sourness. Fresh meat and fish, transferred by this plant, last longer. A yellow dye can be obtained from its roots. The fibers can be used to make nets that do not rot in water. Leaves are an inexhaustible basis for the hostess' fantasy of preparing healthy and wholesome food. We know this plant from Andersen's fairy tale. Personal experience communication with this plant can bring to tears. Finally, even the blind will recognize this plant. It's...Name this plant!
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"Chemical properties of carboxylic acids" - The name of carboxylic acids. The structure of the carboxyl group. Formulas of carboxylic acids. Task. Chemical properties carboxylic acids. functional group. carboxylic acids. Salicylic acid. Chemical properties. Trivial name for carboxylic acids. General properties of carboxylic acids. The road to knowledge.
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