Hydrochloric acid - History, properties and uses

Hydrochloric acid is characterized by being a colorless liquid, and which in turn has a pungent odor, although in some cases it can be noted that the substance has a yellowish tone because it contains chlorine braids, organic matter or in alternative cases iron.

This compound can be obtained by a process of combination and absorption in water of gaseous hydrogen and chlorine, It is well known for its thermal stability qualities, and the various applications that it can be given, in fact it is a chemical that is very useful today for many of the processes that are carried out in industries and manufacturing companies, as well as in chemical laboratories.

The beginnings of this wonderful acid that in the world popularity scale is second, just behind sulfuric acid, were in the medieval age, when instead of existing scientists, or chemists, these compounds were handled by alchemists.

The most important aspects of the history of how this compound was found for the first time, as well as its qualities, aspects, properties, uses and due precautions will be noted below.

What is hydrochloric acid?

Hydrochloric acid is an aqueous solution of the gas known as hydrogen chloride, whose characteristics are that it can be really corrosive and acidic. The most common uses that can be found for this acid are as a chemical reagent. Hydrochloric acid is a compound that can be completely dissociated in aqueous solutions.

This compound has certain characteristics at room temperature, such as having a slight yellow color, is corrosive, has a greater weight in the air, has a very irritating odor, and is flammable, when exposed to air, hydrochloric acid forms highly corrosive of a considered density, which can be noticed by their respective white color, this can also be naturally expelled by volcanoes.

Hydrogen chloride can be formed by burning various compounds, such as plastic, and when it comes into contact with water, it is when hydrochloric acid is generated, these two compounds are highly corrosive.

History 

Known as the spirit of salt by the ancient alchemists of medieval times, exactly in the seventeenth century, hydrochloric acid is a compound to which the discovery was mistakenly attributed to Jabir Ibn Hayyan, because he was the author of a work known as the "Pseudo-Gerber corpus", the work was baptized with this name because Jabir was also known as Gerber.

In Europe there was an incredibly large increase due to alkaline substances, this was during the time of the first industrial revolution, due to this great demand Nicolás Leblanc developed a new method of obtaining, which allowed production to rise in level, reaching mass producing, and in turn making it less expensive to manufacture.

In the Leblanc process coal, limestone, and sulfuric acid are used to convert water into soda, This is achieved by releasing hydrogen chloride as a waste product, which was previously released into the atmosphere, but due to a law that was established in 1863, it forced industries to absorb the waste gas, in water, because of This began to produce hydrochloric acid on a global scale.

The Leblanc process lasted for many years, although in the XNUMXth century it was replaced by a more efficient one, but which as a consequence did not allow the generation of hydrochloric acid, despite this this compound was already widely used worldwide, so the large Industries invested a large part of their time in processes to obtain it, because there was already a demand for hydrochloric acid.

Hydrochloric acid properties

Hydrochloric acid has very common properties in the world of chemistry, such as melting and boiling points, pH and density, which depend on the concentration of the HCl compound in the solid solution. In order to measure the concentration, one must resort to molarity, although this is not in all cases.

The most common hydrochloric acid, which can be found among the best-selling products on the market, usually found in concentrations between 38% and 25%

38 grams of this compound can be diluted in water for every 100 milliliters of it, but at low temperatures it has the ability to form crystals of HCI H2Or with 68% HCl, such a solution is capable of forming an azeotrope.

Due to the organic chlorination reactions of organic substances with di-chlorine, large amounts of hydrochloric acid are formed, this process is very common in large chemical industries.

Cleaning products usually have a concentration of this compound of figures from 10% to 12% usually, which are known as solutions for domestic use.

There are compounds of this type with high concentrations, such as those of 40%, although these are usually a bit dangerous, because the level of evaporation is much higher, so certain measures must be taken to store them.

Another very effective production method to obtain hydrochloric acid is by electrolyzing a common salt solution, which can produce di-chloro, di-hydrogen, and sodium hydroxide. By obtaining di-chlorine gas in this way, it can be combined with di-hydrogen gas to form the HCI compound, which is characterized by being chemically pure.

Chemistry

Hydrogen chloride is known as a monoprotic acidThis is because in its composition which is made up of a single ion known as a proton, which has the ability to bind to a water molecule to obtain an oxonium ion, this is as long as it is in an aqueous solution .

Hydrochloric acid has another ion that is chloride, due to this, this compound has the ability to be used to create salts that are known as chlorides, such as sodium chloride.

Hydrochloric acid is known to have a really strong structure, since it can be completely dissociated in water.

Monoprotic acids can indicate the level of dissociation of water by means of a dissociation constant which is represented by Ka, When you have an aqueous solution of HCl, the value of the constant described above is usually high in strong acids such as HCl when chlorides are added, such as NaCl, in these processes the final PH remains practically the same, due to that its change is not of much relevance, which indicates that a remarkably weak conjugate base is obtained called the CI ion, which shows that the HCI is in an almost complete state of dissociation when it is in aqueous solutions.

This acid despite having characteristics that determine it as a strong acid, it turns out that it is one of the least dangerous to manipulateDespite its notable acidity, it produces the relatively reactive and non-toxic chloride ion.

Chemical analysis is practically its default area, due to the great use it is given, in turn it is very useful in digesting samples for their respective analyzes.

How to get hydrochloric acid

It can be obtained by using sodium chloride and dissolving it in water. In industrial processes it is achieved through the synthesis of sodium chloride, and so that this does not occur violently, the two gases begin to mix once the reaction begins to occur, this is due to the fact that the reaction between chlorine and hydrogen can be explosive in nature. This process is accomplished by passing a particular stream of chlorine gases through a hydrogen flame.

The raw material for this process is sodium chloride. To achieve the necessary levels of chlorine and hydrogen, an electrolysis of the concentrated sodium chloride solution must be carried out, which is more commonly recognized by the name of brine.

Sagua la Grande is a city in Cuba, whose country is home to a chemical plant known as Electroquímica de Sagua, in which this compound is obtained through the processes described above. The real name of the plant is "Elpidio Sosa".

Most common applications of this compound

Hydrochloric acid has great qualities, so it has the capacity to fulfill several tasks, because it is considered a strong, volatile acid and best of all, it is a cheap acid. The most common use that can be found for this compound is as a descaler, since it can remove limestone.

In food production industries, its use can be observed to dissolve the bones with which gelatin is prepared.

This acid can also be used to eliminate wastes that alkaline substances can leave behind, in turn it is used to regulate the PH of some solutions, or to better understand their acidity, such as food, water, and pharmaceutical products.

An important use is to dissolve the oxide layer that can form on metal surfaces, this process is characteristic of the metallurgical process industry.

One of the most important applications is to regenerate ion exchange resins, for which a high quality hydrochloric acid must be used.

Risks and harmful effects

The mishandling and manipulation of this compound, or of the processes to obtain it, can have serious consequences, about which it is extremely important to have at least a minimum knowledge, for that simple reason some harmful effects and risks will be shown below. That can bring consuming, or having contact with hydrochloric acid.

Harmful effects

The harmful effects of hydrochloric acid can be suffered even when being a little away from its reactions, because it is a very irritating and corrosive compound for any type of tissue, so being in its vicinity or establishing direct contact could cause including death.

Based on the concentration and the distance of this compound, it could cause from a slight irritation, to serious burns on the skin of humans, even an exposure that can be considered as low in the long term can produce some symptoms such as irritation in the throat, in the eyes, respiratory problems, and discoloration in the teeth.

Despite the fact that this compound is extremely harmful to humans, the stomach has at least 3% hydrochloric acid, because it helps with the decomposition of food, and the denaturation of vitamins.

The lack of this compound in the stomach can cause severe diseases such as hypochlorhydria and achlorhydria, which are possible catapults for a severe disease known as gastroenteritis.

In industries, it has been possible to observe and study that several workers exposed to this acid have died from lung cancer caused by the same hydrochloric acid.

Most common risks

There are various risks that can arise when coming into contact of any kind with hydrochloric acid, which can be by inhaling it, ingesting it, or by having contact with the eyes or the skin, which will be described below.

Inhalation hazards

Exposure by inhalation usually affects the respiratory system, and by default the respiratory system, causing diseases such as acute bronchitis, severe corrosion of the respiratory tract, and irritation of the respiratory tract.

In order to combat the symptoms caused by exposure to this compound, it is necessary to first observe the seriousness of the matter, for example in one of the worst cases that the affected person suffers from respiratory arrest, it is necessary to perform a cardio-pulmonary resuscitation or better known as CPR, and in calmer cases, the affected person should be taken to a place with fresh air, kept at a constant temperature and kept completely still.

Risks to the eyes

The exposure of the visual organs can have quite serious consequences for them, and by default for the visual health of the person, because they can suffer from inflammation in the eye, eye irritation and nasal irritation, which can lead to extra a nasal ulcer, and in more severe cases necrosis in the eyes, which means that the cells of the tissues of the eye begin to break down and die.

In order to treat the symptoms, or the exposure itself to hydrochloric acid, the exposed person must begin a process of washing the eyes with plenty of water, this procedure must last at least 15 minutes. It is very important not to mix the chlorine at all, or to be exposed to it after the hydrochloric acid.

Risks to the skin

Skin that suffers from near or far exposure can lead to skin irritation, and even severe burns to skin tissues, as well as cases of ulcers.

To treat a person who has suffered from exposure to hydrochloric acid on the skin, all clothing should be cut and removed, which includes pants, shirts, shoes, socks, among others, and then wash thoroughly water the affected area for at least 20 minutes.

Ingestion risks

The most common risks after ingestion of this compound are gastritis, stomach edema, necrosis of stomach tissues and nearby organs, hemorrhagic gastritis and stomach burns.

In order to treat and help an individual who has suffered from an exposure of this type, which could be said to be the most serious, because it enters the body, it is to make him drink large amounts of water, or milk, and never, under any circumstances should vomiting be induced.