Hydrochloric acid- a chemical substance that is presented in the form of the interaction of water and hydrogen chloride. In its pure form, the acid has no color. The technical form of the acid has a yellowish tint, because it contains iron, chlorine and some other elements. Hydrochloric acid is used in many areas of human life. The fields of application of hydrochloric acid are very diverse. Let's consider them further.
The use of hydrochloric acid in industry
For example, the food industry uses acid as a food additive E507. This additive is used in the manufacturing process of vodka products, as well as various syrups. The use of hydrochloric acid in the food industry mainly plays the role of a regulator of the acid state of products. In metallurgy, technical hydrochloric acid is popular. It is used to clean metal before soldering or tinning. Etching and pickling in electroforming is not complete without the participation of hydrochloric acid. It creates an active environment for the above mentioned processes.
In order for the use of hydrochloric acid in industry not to create unnecessary problems, it is necessary to approach the choice of its type and concentration with responsibility.
The use of hydrochloric acid in everyday life
You probably have not thought about the composition of cleaning products that you use daily. Many of them contain hydrochloric acid. Use in everyday life, for the toilet: we use products that are highly acidic, which is why they should only be used with rubber gloves. This will keep your hands from getting irritated.
Housewives use a solution of hydrochloric acid at home. Using it as a stain remover helps get rid of rust or ink on clothes. Hydrochloric acid should be stored in glass containers out of the reach of small children. If hydrochloric acid has got on the skin or mucous membranes, it is necessary to immediately wash the affected area with running water. The use of hydrochloric acid at home should be carried out in compliance with safety rules. In addition to the ability to remove difficult stains from clothes, hydrochloric acid is used to combat scale. In order not to aggravate the situation when cleaning dirty dishes, it is recommended to use a certain concentration of acid. In these cases, inhibited hydrochloric acid is used, the use of which allows you to maintain the integrity of dishes made of fragile materials.
To keep your home and clothes clean, you must have hydrochloric acid at home. Use in everyday life should be extremely careful so as not to harm yourself and the things you interact with.
The use of hydrochloric acid in medicine
Hydrochloric acid is one of the components of human gastric juice. Therefore, in case of a decrease in its concentration, medications based on hydrochloric acid are prescribed. The use of hydrochloric acid in medicine plays a special role in the health of a person with diseases of the digestive tract. Due to the presence of a certain amount of hydrochloric acid in the gastric juice, the food is digested, and the microorganisms that enter the stomach die.
Hydrochloric acid is also used to treat specific skin diseases (warts). The use in folk medicine has become widespread: to improve digestion with low acidity of gastric juice, it is necessary to take hydrochloric acid preparations before eating. The use of hydrochloric acid (salts) helps in the fight against digestive disorders.
The use of hydrochloric acid in construction
Hydrochloric acid is used to improve the quality of many construction processes. For example, adding hydrochloric acid to a concrete mix increases its frost resistance. Also, the mixture hardens faster, and the masonry becomes more resistant to moisture. It is also known the use of hydrochloric acid in construction as a limestone cleaner. Red brick is cleaned of dirt and traces of building materials with a 10% hydrochloric acid solution. It is important to remember that not all types of bricks are affected by hydrochloric acid without damaging the structure of the building product. Therefore, you need to use only ten percent hydrochloric acid. A chemical solution of hydrochloric acid significantly saves finances, because other cleaners can cost ten times more.
The low cost does not make the use of hydrochloric acid less effective. Acid is used in many industries: from medical to construction. But, like all other acids, hydrochloric acid has the ability to irritate the skin, and high concentrations can lead to burns.
You can buy hydrochloric acid online by clicking on the link
Hydrochloric acid is a solution of gaseous hydrogen chloride HCl in water. The latter is a hygroscopic colorless gas with a pungent odor. Commonly consumed concentrated hydrochloric acid contains 36-38% hydrogen chloride and has a density 1.19 g/cm3. Such an acid smokes in air, since gaseous HCl; when combined with air moisture, tiny droplets of hydrochloric acid are formed.
Pure acid is colorless, while technical acid has a yellowish tint caused by traces of compounds of iron, chlorine and other elements ( FeCl 3 ).
Often a dilute acid containing 10% and less hydrogen chloride. Dilute solutions do not emit gaseous HCl and do not smoke in dry or humid air.
Hydrochloric acid is a volatile compound, as it evaporates when heated. It is a strong acid and reacts vigorously with most metals. However, metals such as gold, platinum, silver, tungsten and lead , hydrochloric acid is practically not etched. Many base metals, when dissolved in acid, form chlorides, for example zinc :
Zn + 2HCl \u003d ZnCl 2 + H 2.
Hydrochloric acid is widely used in industry for extracting metals from ores, pickling metals, etc. It is also used in the manufacture of soldering liquid, in the deposition silver and as part of royal vodka.
The scale of the use of hydrochloric acid in industry is less than nitric . This is due to the fact that hydrochloric acid causes corrosion of steel equipment. In addition, its volatile vapors are quite harmful and also cause corrosion of metal products. This must be taken into account when storing hydrochloric acid. Hydrochloric acid is stored and transported in rubber-lined tanks and barrels, i.e. in vessels, the inner surface of which is covered with acid-resistant rubber, as well as in glass bottles and polyethylene utensils.
Hydrochloric acid is used to produce chlorides zinc, manganese , iron and other metals, as well as ammonium chloride. Hydrochloric acid is used to clean the surfaces of metals, vessels, wells from carbonates, oxides and other sediments and contaminants. In this case, special additives are used - inhibitors that protect the metal from dissolution and corrosion, but do not delay the dissolution of oxides, carbonates and other similar compounds.
HCl used in the industrial production of synthetic resins, rubbers. It is used as a raw material in the production of methyl chloride from methyl alcohol, ethyl chloride from ethylene, and vinyl chloride from acetylene.
HCl poisonous. Poisoning usually occurs by mist formed when the gas interacts with water vapor in the air. HCl it is also absorbed on the mucous membranes with the formation of an acid that causes severe irritation. During prolonged work in the atmosphere HCl there are catarrhs of the respiratory tract, tooth decay, ulceration of the nasal mucosa, gastrointestinal disorders. Permissible content HCl in the air of working premises, no more 0 , 005 mg/l. For protection use a gas mask, goggles, rubber gloves, shoes, apron.
At the same time, our digestion is impossible without hydrochloric acid, its concentration in gastric juice is quite high. If the acidity in the body is lowered, then digestion is disturbed, and doctors prescribe such patients to take hydrochloric acid before eating.
In water it is called hydrochloric acid ( HCl).
Physical properties of hydrochloric acid
Under normal conditions, hydrochloric acid is a clear, colorless liquid with a sharp, unpleasant odor.
Concentrated hydrochloric acid contains 37% hydrogen chloride. Such an acid "smokes" in air. Hydrogen chloride is released from it, which, with water vapor in the air, forms a "fog" consisting of small droplets of hydrochloric acid. Hydrochloric acid is slightly heavier than water (the specific gravity of 37% hydrochloric acid is 1.19).
School laboratories use mostly dilute hydrochloric acid.
Chemical properties of hydrochloric acid
Hydrochloric acid solution has a sour taste. Litmus in this solution is red, while phenolphthalein remains colorless.
Substances whose color changes from the action of alkalis and acids are called indicators.
Litmus, phenolphthalein - indicators for acids and alkalis. With the help of indicators, you can determine whether there is acid or alkali in the solution.
Hydrochloric acid reacts with many metals. The interaction of hydrochloric acid with sodium occurs especially rapidly. This can be easily seen from the experiment that can be carried out in the device.
Concentrated hydrochloric acid is poured into a test tube up to about 1/4 of its volume, fixed in a tripod and a small piece of sodium (the size of a pea) is lowered into it. Hydrogen is released from the test tube, which can be set on fire, and small crystals of common salt settle to the bottom of the test tube.
From this experience it follows that sodium displaces hydrogen from the acid and combines with the rest of its molecule:
2Na + 2HCl \u003d 2NaCl + H 2?
Under the action of hydrochloric acid on zinc, hydrogen is released, and the substance zinc chloride ZnCl 2 remains in the solution.
Since zinc is divalent, each zinc atom replaces two hydrogen atoms in two hydrochloric acid molecules:
Zn + 2HCl \u003d ZnCl 2 + H 2?
Hydrochloric acid also acts on iron, aluminum and many other metals.
As a result of these reactions, hydrogen is released, and metal chlorides remain in the solutions: ferric chloride FeCl 2, aluminum chloride AlCl 3, etc.
These metal chlorides are the products of substitution of hydrogen in hydrochloric acid by metals.
Compound substances that can be considered as products of substitution of hydrogen in an acid by a metal are called salts.
Metal chlorides are salts of hydrochloric acid.
Neutralization reaction (equation)
A very important chemical property of hydrochloric acid is its interaction with bases. Consider first its interaction with alkalis, for example with caustic soda.
To this end, pour a small amount of dilute sodium hydroxide solution into a glass cup and add a few drops of litmus solution to it.
The liquid will turn blue. Then we will pour in small portions into the same glass a solution of hydrochloric acid from a graduated tube (burette) until the color of the liquid in the glass changes to violet. Violet litmus indicates that the solution contains neither acid nor alkali.
Such a solution is called neutral. After boiling water out of it, table salt NaCl will remain. Based on this experience, it can be concluded that when solutions of caustic soda and hydrochloric acid are poured, water and sodium chloride are obtained. Water molecules were formed from the combination of hydrogen atoms (from acid molecules) with hydroxyl groups (from alkali molecules). Molecules of sodium chloride were formed from sodium atoms (from alkali molecules) and chlorine atoms - acid residues. The equation for this reaction can be written as follows:
Na |OH + H| Cl \u003d NaCl + H 2 O
Other alkalis also react with hydrochloric acid - caustic potash, caustic calcium.
Let's get acquainted with how hydrochloric acid reacts with insoluble bases, for example, with copper oxide hydrate. To this end, we will place a certain amount of this base in a glass and carefully add hydrochloric acid to it until the copper oxide hydrate is completely dissolved.
After evaporation of the blue solution thus obtained, crystals of copper chloride CuCl 2 are obtained. Based on this, the following equation can be written:
And in this case, a reaction similar to the interaction of this acid with alkalis took place: hydrogen atoms from acid molecules combined with hydroxyl groups from base molecules, water molecules were formed. Copper atoms combined with chlorine atoms (residues from acid molecules) and formed salt molecules - copper chloride.
Hydrochloric acid reacts in the same way with other insoluble bases, for example, with iron oxide hydrate:
Fe(OH) 3 + 3HCl = 3H 2 O + FeCl 3
The reaction of an acid with a base to form a salt and water is called neutralization.
Hydrochloric acid is found in small amounts in the gastric juice of humans and animals and plays an important role in digestion.
Hydrochloric acid is used to neutralize alkalis, to obtain chloride salts. It also finds application in the production of some plastics, medicines.
The use of hydrochloric acid
Hydrochloric acid has a wide range of uses in the national economy, and you will often meet it when studying chemistry.
Large amounts of hydrochloric acid are used to pickle steel. Nickel-plated, zinc-plated, tin-plated (tin-plated), chrome-plated products are widely used in everyday life. To cover steel products and sheet iron with a layer of protective metal, the film of iron oxides must first be removed from the surface, otherwise the metal will not stick to it. Removal of oxides is achieved by etching the product with hydrochloric or sulfuric acid. The disadvantage of etching is that the acid reacts not only with the oxide, but also with the metal. To avoid this, a small amount of an inhibitor is added to the acid. Inhibitors are substances that slow down an unwanted reaction. Inhibited hydrochloric acid can be stored in steel containers and transported in steel tanks.
A solution of hydrochloric acid can also be bought at a pharmacy. Doctors prescribe a dilute solution of her patients with low acidity of gastric juice.
For safety and ease of use, it is recommended to buy the most dilute acid, but sometimes it has to be diluted even more at home. Be sure to wear body and face protection as concentrated acids cause severe chemical burns. To calculate the required amount of acid and water, you will need to know the molarity (M) of the acid and the molarity of the solution you need to get.
Steps
How to calculate the formula
- The formula will also use the value V 1. This is the volume of acid we will be adding to the water. We probably won't need the whole bottle of acid, though we don't know the exact amount yet.
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Decide what the result should be. The required concentration and volume of acid is usually indicated in the text of the chemistry problem. For example, we need to dilute the acid to a value of 2M, and we need 0.5 liters of water. Let us denote the required concentration as C2, and the required volume - as V 2.
- If you are given other units, first convert them to molarity units (moles per liter) and liters.
- If you don't know what concentration or volume of acid you need, ask a teacher or someone well versed in chemistry.
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Write a formula to calculate the concentration. Each time you dilute an acid, you will use the following formula: C 1 V 1 = C 2 V 2. This means that the original concentration of a solution times its volume equals the concentration of the diluted solution times its volume. We know this to be true because the concentration times the volume equals the total acid, and the total acid will remain the same.
- Using the data from the example, we write this formula as (6M)(V 1)=(2M)(0.5L).
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Solve equation V 1. The value of V 1 will tell us how much concentrated acid we need to get the desired concentration and volume. Let's rewrite the formula as V 1 \u003d (C 2 V 2) / (C 1), then substitute the known numbers.
- In our example, we get V 1 =((2M)(0.5L))/(6M). This equals approximately 167 milliliters.
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Calculate the required amount of water. Knowing V 1, that is, the amount of acid available, and V 2, that is, the amount of solution that you get, you can easily calculate how much water you need. V 2 - V 1 = required volume of water.
- In our case, we want to get 0.167 liters of acid per 0.5 liters of water. We need 0.5 liters - 0.167 liters \u003d 0.333 liters, that is, 333 milliliters.
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Put on safety goggles, gloves and a gown. You will need special glasses that will cover your eyes and sides. Wear gloves and a gown or apron to avoid burning your skin and clothes.
Work in a well ventilated area. If possible, work under the included hood - this will prevent acid vapors from harming you and surrounding objects. If you don't have a hood, open all windows and doors or turn on a fan.
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Find out where the source of running water is. If acid gets in your eyes or on your skin, you will need to rinse the affected area under cool, running water for 15 to 20 minutes. Do not start work until you find out where the nearest sink is.
- When rinsing your eyes, keep them open. Look up, down, to the sides so that the eyes are washed from all sides.
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Know what to do if you spill acid. You can buy a special kit for collecting spilled acid, which will include everything you need, or purchase neutralizers and absorbents separately. The process described below is applicable to hydrochloric, sulfuric, nitric and phosphoric acids. Other acids may require different handling.
- Ventilate the room by opening windows and doors and turning on the exhaust hood and fan.
- Apply a little sodium carbonate (baking soda), sodium bicarbonate, or calcium carbonate on the outer edges of the puddle to prevent splashing of acid.
- Gradually fill the entire puddle towards the center until you have completely covered it with the neutralizing agent.
- Mix thoroughly with a plastic stick. Check the pH value of the puddle with litmus paper. Add more neutralizing agent if this value exceeds 6-8, and then wash the area with plenty of water.
Explore what you already have. Look for the acid concentration symbol on the packaging or in the task description. Usually this value is indicated as molarity, or molar concentration (briefly - M). For example, 6M acid contains 6 moles of acid molecules per liter. Let's call this initial concentration C1.
How to dilute acid
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Cool the water with people. This should only be done if you will be working with high concentrations of acids, such as 18M sulfuric acid or 12M hydrochloric acid. Pour water into a container, place the container on ice for at least 20 minutes.
- Most often, water at room temperature is sufficient.
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Pour distilled water into a large flask. For tasks that require extreme precision (for example, titrimetric analysis), use a volumetric flask. For all other purposes, a regular conical flask will do. The entire required volume of liquid must fit in the container, and there must also be room so that the liquid does not spill.
- If the capacity of the container is known, there is no need to accurately measure the amount of water.
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Add a small amount of acid. If you are working with small amounts of water, use a graduated or measuring pipette with a rubber tip. If the volume is large, insert a funnel into the flask and carefully pour the acid in small portions with a pipette.
- Do not use pipettes in the chemistry lab that require air to be sucked in by mouth.
- (HCl), an aqueous solution of hydrogen chloride, a colorless gas with a pungent odor. Obtained by the action of sulfuric acid on common salt, as a by-product of the chlorination of hydrocarbons, or by the reaction of hydrogen and chlorine. Hydrochloric acid is used for ... ... Scientific and technical encyclopedic dictionary
Hydrochloric acid- - HCl (SC) (hydrochloric acid, hydrochloric acid, hydrogen chloride) is a solution of hydrogen chloride (HCl) in water, an antifreeze additive. It is a colorless liquid with a pungent odor, without suspended particles. ... ... Encyclopedia of terms, definitions and explanations of building materials
- (hydrochloric acid) solution of hydrogen chloride in water; strong acid. A colorless liquid fuming in air (technical hydrochloric acid is yellowish due to impurities of Fe, Cl2, etc.). Maximum concentration (at 20 .C) 38% by mass, ... ... Big Encyclopedic Dictionary
HYDROCHLORIC ACID- (Acidum muriaticum, Acid, hydrochloricum), a solution of hydrogen chloride (HC1) in water. In nature, it occurs in the water of some sources of volcanic origin, and is also found in gastric juice (up to 0.5%). Hydrogen chloride can be obtained ... Big Medical Encyclopedia
HYDROCHLORIC ACID- (hydrochloric acid, hydrochloric acid) a strong monobasic volatile acid with a pungent odor, an aqueous solution of hydrogen chloride; the maximum concentration is 38% by mass, the density of such a solution is 1.19 g/cm3. Used in... ... Russian encyclopedia of labor protection
HYDROCHLORIC ACID- (hydrochloric acid) HCl aqueous solution of hydrogen chloride, strong monobasic acid, volatile, with a pungent odor; impurities of iron, chlorine stain it yellowish. The concentrated S. to sell contains 37% ... ... Great Polytechnic Encyclopedia
Exist., Number of synonyms: 1 acid (171) ASIS Synonym Dictionary. V.N. Trishin. 2013 ... Synonym dictionary
Modern Encyclopedia
Hydrochloric acid- HYDROGENIC ACID, aqueous solution of hydrogen chloride HCl; a fuming liquid with a pungent odor. Hydrochloric acid is used to obtain various chlorides, pickling metals, processing ores, in the production of chlorine, soda, rubber, etc. ... ... Illustrated Encyclopedic Dictionary
- (hydrochloric acid), a solution of hydrogen chloride in water; strong acid. A colorless liquid "fuming" in air (technical hydrochloric acid is yellowish due to impurities of Fe, Cl2, etc.). Maximum concentration (at 20°C) 38% by mass,… … encyclopedic Dictionary
