1.2679; G crit 51.4 ° C, p crit 8.258 MPa, d crit 0.42 g/cm 3 ; -92.31 kJ/, DH pl 1.9924 kJ/ (-114.22°C), DH isp 16.1421 kJ/ (-8.05°C); 186.79 J/(mol K); (Pa): 133.32 10 -6 (-200.7 °C), 2.775 10 3 (-130.15 °C), 10.0 10 4 (-85.1 °C), 74, 0 10 4 (-40°C), 24.95 10 5 (O °C), 76.9 10 5 (50 °C); level of temperature dependence logp(kPa) = -905.53/T+ 1.75lgT- -500.77·10 -5 T+3.78229 (160-260 K); coefficient 0.00787; g 23 mN/cm (-155°C); r 0.29 10 7 Ohm m (-85°C), 0.59 10 7 (-114.22°C). See also table. 1.
R-value of HC1 at 25 °C and 0.1 MPa (mol %): in pentane - 0.47, hexane - 1.12, heptane - 1.47, octane - 1.63. The P-rhythm of HC1 in alkyl and aryl halides is low, for example. 0.07 / for C 4 H 9 C1. The pH value in the range from -20 to 60° C decreases in the series dichloroethane-tri-chloroethane-tetrachloroethane-trichlorethylene. The pH value at 10°C in a series is approximately 1/, in carbon ethers it is 0.6/, in carbonic compounds it is 0.2/. Stable R 2 O · HCl are formed. The P-rhythm of HC1 in obeys and is for KCl 2.51·10 -4 (800°С), 1.75·10 -4 / (900°С), for NaCl 1.90·10 -4 / (900° WITH).
Salt room. HCl in water is highly exothermic. process, for infinitely divisible. water solution D H 0 HCl -69.9 kJ/, Cl -- 167.080 kJ/; HC1 is completely ionized. The pH value of HC1 depends on the temperature (Table 2) and the partial HC1 in the gas mixture. Density of salt decomposition. and h at 20 °C are presented in table. 3 and 4. As the temperature increases, h hydrochloric acid decreases, for example: for 23.05% hydrochloric acid at 25 °C h 1364 mPa s, at 35 °C 1.170 mPa s hydrochloric acid containing h per 1 HC1, is [kJ/(kg K)]: 3.136 (n = 10), 3.580 (n = 20), 3.902 (n = 50), 4.036 (n = 100), 4.061 (n = 200).
HCl forms c (Table 5). In the HCl-water system there are three eutectics. points: - 74.7 °C (23.0% by weight HCl); -73.0°C (26.5% HCl); -87.5°C (24.8% HC1, metastable phase). Known HCl nH 2 O, where n = 8. 6 (mp. -40 ° C), 4. 3 (mp. -24.4 ° C), 2 (mp. -17.7 °C) and 1 (mp -15.35°C). crystallizes from 10% hydrochloric acid at -20, from 15% at -30, from 20% at -60 and from 24% at -80°C. The P-value of halides decreases with increasing HCl in hydrochloric acid, which is used for their.
Chemical properties. Pure dry HCl begins to dissociate above 1500°C and is chemically passive. Mn. , C, S, P do not interact. even with liquid HCl. C, reacts above 650 °C, with Si, Ge and B-c present. AlCl 3, with transition metals - at 300 °C and above. It is oxidized by O 2 and HNO 3 to Cl 2, with SO 3 it gives C1SO 3 H. About the solutions with org. connections see .
WITH Olina is chemically very active. Dissolves with the release of H 2 everything that has a negative. ,with many and forms, releases free. who are you from such people as, etc.
Receipt. In the HCl industry, the following is obtained. methods - sulfate, synthetic. and from exhaust gases (by-products) of a number of processes. The first two methods lose their meaning. Thus, in the USA in 1965 the share of waste hydrochloric acid was 77.6% of the total production volume, and in 1982 - 94%.
The production of hydrochloric acid (reactive, obtained by the sulfate method, synthetic, waste gas) is to obtain HCl from the last. his . Depending on the method of heat removal (reaches 72.8 kJ/), processes are divided into isothermal, adiabatic. and combined.
The sulfate method is based on interaction. NaCl with conc. H 2 SO 4 at 500-550 ° C. Reaction contain from 50-65% HCl (muffle) to 5% HCl (reactor with). It is proposed to replace H 2 SO 4 with a mixture of SO 2 and O 2 (process temperature approx. 540 °C, cat. Fe 2 O 3).
The direct synthesis of HCl is based on the chain reaction: H 2 + Cl 2 2HCl + 184.7 kJ K p is calculated by the equation: logK p = 9554/T- 0.5331g T+ 2.42.
The reaction is initiated by light, moisture, solid porous (, porous Pt) and certain minerals. in-you ( , ). Synthesis is carried out with an excess of H 2 (5-10%) in combustion chambers made of steel and refractory bricks. Naib. modern material that prevents HCl contamination, graphite, impregnated phenol-formal. resins. To prevent explosiveness, mix directly in the burner flame. To the top. the combustion chamber area is installed to cool the reaction. up to 150-160°C. Power modern graphite reaches 65 tons/day (in terms of 35% salt). In case of H2 deficiency, dil. is used. process modifications; for example, pass a mixture of Cl 2 and water through a layer of porous hot water:
2Cl 2 + 2H 2 O + C: 4HCl + CO 2 + 288.9 kJ
The temperature of the process (1000-1600 °C) depends on the type and presence of impurities in it, which are (for example, Fe 2 O 3). It is promising to use a mixture of CO with:
CO + H 2 O + Cl 2: 2HCl + CO 2
More than 90% of hydrochloric acid in developed countries is obtained from waste HCl, formed during the dehydrochlorination of org. compounds, chlororg. waste, obtaining non-chlorinated potash. etc. Abgases contain various. quantity of HC1, inert impurities (N 2, H 2, CH 4), poorly soluble in org. substances (,), water-soluble substances (acetic acid), acidic impurities (Cl 2, HF, O 2) and. Application of isothermal advisable when the content of HC1 in exhaust gases is low (but when the content of inert impurities is less than 40%). Naib. Film ones are promising, making it possible to extract from 65 to 85% HCl from the initial exhaust gas.
Naib. Adiabatic schemes are widely used. . Abgases are introduced into the lower part, and (or diluted salt) - countercurrent to the upper one. The salt water is heated to temperature due to the heat of HCl. The change in temperature and HCl is shown in Fig. 1. The temperature is determined by the temperature corresponding to the temperature (max. boiling point of the azeotropic mixture - approx. 110°C).
In Fig. 2 shows a typical adiabatic circuit. HCl from exhaust gases formed during (eg, production). HCl is absorbed in 1, and the residues are poorly soluble in org. the substances are separated from the after in apparatus 2, further purified in the tail column 4 and separators 3, 5 and commercial salt is obtained.
Rice. 1. T-p distribution diagram (curve 1) and
Today we invite you to talk about the preparation and use of hydrochloric acid solution and the acid itself in particular. It has found wide application in various sectors of human activity. It is also used in medicine.
The use of hydrochloric acid in medicine.
Hydrochloric acid promotes the following processes:
equalizes the acid-base balance of the body;
treats oncological diseases;
inhibits the development of malignant tumors;
digests proteins in the stomach.
Treatment of low stomach acidity with hydrochloric acid.
How to prepare a solution of hydrochloric acid and before treating low acidity, you must consult a doctor and consult with him and under no circumstances attempt any self-medication. He will prescribe you treatment according to individual characteristics your body, as well as taking into account the results of your tests.
In addition to medications with hydrochloric acid, you can take medications that help stimulate the production of hydrochloric acid in the body. In addition, today herbal remedies have been developed (wormwood, peppermint, calamus), which also stimulate the production of hydrochloric acid in the body, which helps increase the level of stomach acidity.
Using drugs containing hydrochloric acid, you can prevent stomach cancer, reduce the risk of hepatitis, as well as diseases such as diabetes mellitus, psoriasis, rheumatoid arthritis, eczema, cholelithiasis, rosacea, urticaria, asthma and many others.
How to prepare a solution of hydrochloric acid and application.
In order not to wonder how to prepare a solution of hydrochloric acid, we suggest studying the following information that will be useful to you. The prepared solution with hydrochloric acid is sometimes called aqua regia. This cooking recipe was invented by Bolotov and to prepare it we will need the following substances. IN liter jar add 0.5 cups of grape vinegar to water, then 1-2 teaspoons of sulfuric acid and 1 tablespoon of 38 percent hydrochloric acid, without disturbing this sequence. At the end you need to add 4 tablets of nitroglycerin. Using the resulting solution of hydrochloric acid and other ingredients, it is possible to break down cancer cells that provoke the appearance of a disease such as cancer. As for use, you need to use such a solution three times a day, 1-2 teaspoons, which are diluted in 0.5 glasses of liquid (this can be plain water, tea or coffee) before or after meals. If the disease has taken an acute form, the dose can be increased to 1 tablespoon per half glass of water.
Treatment of hemorrhoids with hydrochloric acid solution.
Due to a sedentary lifestyle, a disease such as hemorrhoids can develop. To treat this disease, they most often resort to folk medicine. The use of such a recipe is considered very effective. Take half a glass of water and add 1-2 tablespoons of a 3-5% hydrochloric acid solution. It is recommended to consume the resulting solution half a glass before meals.
Thus, knowing how to prepare a solution of hydrochloric acid, and having information about what it is used for, you have a chance, at home, to be cured of many diseases.
Hydrochloric acid is a clear, colorless or yellowish liquid without suspended or emulsified particles.
Hydrochloric acid is a solution of hydrogen chloride gas HCl in water. The latter is a hygroscopic, colorless gas with a pungent odor. Typically used concentrated hydrochloric acid contains 36–38% hydrogen chloride and has a density of 1.19 g/cm3. Such an acid smokes in air because gaseous HCl is released from it; When combined with air moisture, tiny droplets of hydrochloric acid are formed. It is a strong acid and reacts vigorously with most metals. However, metals such as gold, platinum, silver, tungsten and lead are practically not etched by hydrochloric acid. Many base metals, when dissolved in acid, form chlorides, for example zinc:
Zn + 2HCl = ZnCl 2 + H 2
Pure acid is colorless, but technical acid has a yellowish tint caused by traces of compounds of iron, chlorine and other elements (FeCl3). Dilute acid containing 10% or less hydrogen chloride is often used. Dilute solutions do not emit HCl gas and do not smoke in either dry or humid air.
Application of hydrochloric acid
Hydrochloric acid is widely used in industry for extracting metals from ores, etching metals, etc. It is also used in the manufacture of soldering fluid, in the deposition of silver, and as a component of aqua regia.
The scale of use of hydrochloric acid in industry is less than that of nitric acid. 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 rubberized tanks and barrels, i.e. in vessels inner surface which are covered with acid-resistant rubber, as well as in glass bottles and polyethylene containers.
Hydrochloric acid is used to produce chlorides of zinc, manganese, iron and other metals, as well as ammonium chloride. Hydrochloric acid is used to clean the surfaces of metals, vessels, and wells from carbonates, oxides and other sediments and contaminants. In this case, special additives are used - inhibitors, which protect the metal from dissolution and corrosion, but do not delay the dissolution of oxides, carbonates and other similar compounds.
HCl is used in the industrial production of synthetic resins and rubbers. It is used as a raw material in the production of methyl chloride from methyl alcohol, ethyl chloride from ethylene, vinyl chloride from acetylene.
Hydrochloric acid poisoning
HCl is poisonous. Poisoning usually occurs through fog formed when gas interacts with water vapor in the air. HCl is also absorbed on the mucous membranes with the formation of acid, causing severe irritation. With prolonged work in an HCl atmosphere, catarrh of the respiratory tract, tooth decay, ulceration of the nasal mucosa, and gastrointestinal disorders are observed. The permissible content of HCl in the air of working premises is no more than 0.005 mg/l. For protection, use a gas mask, safety glasses, rubber gloves, shoes, and an 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 low, then digestion is impaired, and doctors prescribe such patients to take hydrochloric acid before eating.
Household use of hydrochloric acid
Concentrated “hodgepodge” is mixed with water in any proportion for household needs. A strong solution of this inorganic acid It easily cleans earthenware plumbing fixtures from limescale and rust, and weaker ones can remove stains of rust, ink, and berry juice from fabrics.
If you look closely, the “Toilet Duck” toilet bowl cleaner says that it contains hydrochloric acid, so you need to work with it in rubber gloves and protect your eyes from splashes.
In addition, the life of no one is unthinkable without this acid - it is contained in the stomach and it is thanks to it that food that enters the stomach dissolves (digests).
In addition, this acid serves as the first barrier against pathogenic bacteria that enter the stomach - they die in an acidic environment.
Well, people suffering from gastritis with high acidity are also very familiar with this acid. They even reduce its effect so that it does not destroy the walls of the stomach, using special drugs that interact with it and reduce its concentration.
The most popular are preparations containing magnesium and aluminum oxides, for example, Maalox. However, there are also extreme sports people who drink baking soda, although it has already been proven that this only leads to temporary relief.
Hydrochloric acid is one of the most powerful and dangerous substances for humans on the list of hazardous substances. However, what is surprising is that it exists in the body of every person: hydrochloric acid is an integral part of gastric juice and plays an important role in the digestive process. In an amount of 0.2%, it promotes the transition of food masses from the stomach to the duodenum and neutralizes microbes entering the stomach from external environment. It also activates the enzyme pepsinogen, participates in the formation of secretin and some other hormones that stimulate the activity of the pancreas. For this purpose, it is used in medicine, prescribing its solution to patients to increase the acidity of gastric juice. In general, hydrochloric acid has wide applications in our lives. For example, in heavy industry - for the production of chlorides of various metals, in the textile industry - for the production of synthetic dyes; For food industry acetic acid is made from it, for pharmaceutical - activated carbon. It is also a component of various adhesives and hydrolytic alcohol. It is used for etching metals, cleaning various vessels, casing pipes of boreholes from carbonates, oxides and other sediments and contaminants. In metallurgy, hydrochloric acid is used to treat ores, and in the leather industry, leather is used before tanning and dyeing. Hydrochloric acid is transported in glass bottles or rubberized (rubber-coated) metal vessels, as well as in plastic containers.
What is it as a chemical?
Hydrochloric acid, or hydrochloric acid, is an aqueous solution of hydrogen chloride HCl, which is a clear, colorless liquid with a pungent odor of hydrogen chloride. The technical variety of acid has a yellowish-green color due to impurities of chlorine and iron salts. The maximum concentration of hydrochloric acid is about 36% HCl; such a solution has a density of 1.18 g/cm3. Concentrated acid “smoke” in air, since the released gaseous HCl forms tiny droplets of hydrochloric acid with water vapor.
Despite this characteristic, when in contact with air, hydrochloric acid is not flammable or explosive. But at the same time, it is one of the strongest acids and dissolves (with the release of hydrogen and the formation of salts - chlorides) all metals in the voltage series up to hydrogen. Chlorides are also formed when hydrochloric acid reacts with metal oxides and hydroxides. It behaves as a reducing agent with strong oxidizing agents.
Salts of hydrochloric acid are chlorides and, with the exception of AgCl, Hg2Cl2, are highly soluble in water. Materials such as glass, ceramics, porcelain, graphite, and fluoroplastic are resistant to hydrochloric acid.
Hydrochloric acid is obtained from hydrogen chloride in water, which, in turn, is either directly synthesized from hydrogen and chlorine, or obtained by the action of sulfuric acid on sodium chloride.
Industrially produced (technical) hydrochloric acid has a strength of at least 31% HCl (synthetic) and 27.5% HCl (from NaCI). A commercial acid is called concentrated if it contains 24% or more HCl; if the HCl content is less, then the acid is called dilute.
AlexBr 07-02-2010 09:30
There are two blades from our blacksmiths, shx 15 (bearing), I want to etch them with hydrochloric acid, I heard about the interesting results of this process.
They brought me acid, they said it was concentrated.
Now the question is how can I bring it up to 5-10% as needed for etching. Those. should I pour water there or into water and how much if the acid is 100 ml?
I understand the question is a loser, but I finished school and college a long time ago, and I don’t want to learn from my mistakes.
serber 07-02-2010 10:09
Only acid in water! In 1 liter of water 100 ml of HCl, we get a 10% solution
chief 07-02-2010 10:19
quote: Originally posted by serber:
Only acid in water! In 1 liter of water 100 ml of HCl, we get a 10% solution
We won’t get 10%!
Concentrated hydrochloric acid is not sulfuric acid; by definition it cannot be 100 percent, because hydrogen chloride is a gas.
Concentrated HCl - about 35-38 percent. Therefore, it is necessary to dilute approximately three times, and not ten times. If you need to be precise - by density:
http://ru.wikipedia.org/wiki/Hydrochloric acid
hunter1957 07-02-2010 10:29
The maximum achievable concentration of hydrochloric acid is 38-39%; then do the math yourself to get 5% acid. Regarding the etching of steel, there is such a thing that concentrated acids passivate the surface of the steel and the oxide film does not allow further etching.
pereira71 07-02-2010 11:41
Hello!
Now I’ll try to post a table with which you can calculate the percentage dilution of acids. Thanks to our Estonian colleagues.
Damn, it doesn't work...
If possible, let me send it to someone for soap, and you can attach it. Excel file.
Nestor74 07-02-2010 12:55
pereira71
so put it somewhere on any file hosting service, and here it is, using cntrl-C cntrl-V, and that’s fine.
Kerogen 07-02-2010 13:32
quote: Originally posted by AleksBr:
Now the question is how can I bring it up to 5-10% as needed for etching. Those. should I pour water there or into water and how much if the acid is 100 ml?
Dilution calculator
pereira71 07-02-2010 13:54
While I was calving it was already done)))
Thanks Kerogen!
07-02-2010 16:28
Dilute 3-4 times, you will get what you need. What about
quote: Only acid in water!
I beg to differ, SALT can be stirred in any way you like. And SULFURIC acid is really only added to the water in a thin stream while stirring, and certainly in a container that will not crack due to strong heating of the mixture.
And to prepare solutions of other concentrations, I advise you to use the rule of the cross, look here for example