Soda as a chemical compound. What are the chemical properties of baking soda?
Sodium bicarbonate, sodium bicarbonate, sodium bicarbonate, baking soda are the names of the same chemical compound, known to every person as " baking soda". It is a good baking powder for dough. Can be removed with saline solution toothache. But this is not the whole range of applications of this "miracle" substance. In fact, it is difficult to do without sodium bicarbonate in everyday life, in cooking, in medicine, and in many other areas of activity.
History of creation
Baking soda has been used in baking since antiquity. It was found by archaeologists during excavations of caves of the 1st-2nd centuries BC. Then it was mined from the sea or found in the form of a mineral. it chemical compound actively used in ancient Egypt.
First chemical formula compounds - NaHCO3- was established by the French scientist Henri de Monceau. Thanks to this discovery, baking soda began to be obtained synthetically, which significantly reduced its cost and expanded the range of uses. Since the discovery of the formula, the methods of its synthesis have constantly changed, improved, and become more cost-effective.
How to get
The first method for the industrial production of sodium carbonate was to dissolve rock in, mix the solution with limestone and charcoal and subsequent heating in an oven. However, as it turned out, the output was not food, but soda ash. In addition, as a result of such activities, a lot of toxic waste remained (calcium sulfide and hydrogen chloride), so it was quickly abandoned.
Today, baking soda is produced in two ways - “dry” and “wet”, each of which is based on the carbonization reaction (enrichment of the solution with carbon dioxide).
Types of soda
From a chemical point of view and scope, there are several types of soda: food (drinking), calcined (linen) and caustic (sodium hydroxide).
Chemical properties
Sodium bicarbonate is a weak acid salt of carbonic acid. It is a small colorless crystals, which, when the temperature rises to 50-60 ° C, begin to “give up” a carbon dioxide molecule, gradually decomposing to sodium carbonate (soda ash).
Reacts with acids to form salts (chloride, acetate, sodium sulfate) and carbonic acid, which instantly breaks down to water and carbon dioxide. The powder dissolves poorly in water and is easily separated by filtration.
Beneficial features
The benefits of sodium bicarbonate are due to its alkaline pH. It is the ability to react with acids and alkalinize the environment that underlies such useful properties baking soda like:
- acid-neutralizing;
- antiseptic;
- anti-inflammatory;
- antipruritic;
- drying;
- antifungal;
- thinning sputum;
- softening and whitening the skin.
Such a variety of useful properties allows you to use this compound in folk and traditional medicine for the treatment of many diseases and the normalization of human well-being in various pathological and physiological conditions.
Possible harm
Baking soda should be consumed internally in limited quantities and under strict indications. Bicarbonate crystals in large quantities are toxic to the digestive mucosa and can cause severe irritation and allergic responses.
With regular inhalation of carbon dioxide vapors or bicarbonate crystals, for example, in the production of soda, irritation of the respiratory mucosa may occur.
Frequent use of soda solution threatens with persistent organic disorders work digestive system. alkalization occurs gastric juice, as well as a shift to the strongly alkaline side of the intestinal contents.
medical application
Sodium bicarbonate is widely used in medicine. At the same time, soda is used in its various areas: dermatology, gastroenterology, cardiology, pulmonology, dentistry, toxicology, and ENT pathologies. Helps sodium bicarbonate from heartburn, nausea, motion sickness.
This substance is used internally in the form of a soda drink and externally in dry form, in the form of a paste or aqueous solution for rubdowns, lotions, baths.
In dentistry
Rinse with sodium bicarbonate solution oral cavity relieves local inflammation, relieves toothache, strengthens gums, eliminates unpleasant odors. Baking soda can be used as a substitute for toothpaste to whiten teeth.
In gastroenterology
For nausea, make a strong soda solution (1 tablespoon per glass of water) and drink it slowly. With severe heartburn, it is recommended to dissolve a teaspoon of soda in a glass of water and drink. Thus, for some time the condition of patients improves. However, it should be noted that with frequent heartburn, you should consult a doctor, and not be treated with soda at home. The habitual intake of an alkaline solution causes a neutralization reaction between hydrochloric acid and soda, which releases a lot of carbon dioxide, which causes bloating. The resulting carbon dioxide irritates the chemoreceptors of the stomach, thereby stimulating a reflex increase in the formation of gastric juice.
In cardiology
Hydrocarbon baths contribute to the normalization blood pressure and heartbeat, which is useful for interruptions in the work of the heart and blood vessels. Soda increases urination, which reduces the total volume of circulating blood. As a result, the pressure of the blood column on the walls of the vessels decreases and blood pressure drops slightly.
Oral sodium bicarbonate solution sharp rise blood pressure is a first aid for hypertensive crisis at home. If you drink a soda drink along with antihypertensive drugs, this potentiates their effect.
In dermatology
Soap and soda baths and applications help get rid of fungal nail infections, as well as corns and corns. A paste of baking soda and water should be used to treat skin burns when exposed to acids, as well as skin areas with sunburn. Moisten with water with soda dissolved in it, you need to place mosquito bites and other insects on the skin. With severe itching, you can sprinkle the skin with dry powder.
If there are problems with the smell of sweat, the armpits should be treated with a soda solution. Bacteria and fungi that grow in sweat produce acids that cause bad breath. Sodium bicarbonate neutralizes these acids and exhibits a moderate antiseptic effect.
Bicarbonate-based foot baths are made for fungal diseases of the feet and nails. They also help soften rough heel skin before a pedicure. hot tubs from strong solution baking soda help with panaritium ( purulent inflammation under the nail).
With ENT pathologies
Sodium bicarbonate when ingested viscous sputum, reacts with the acids contained in it. The formed bubbles of carbon dioxide and water dilute the sputum, increase its quantity and facilitate coughing.
For the preparation of an expectorant for tracheitis, laryngitis, bronchitis, as well as for strong cough a teaspoon of baking soda is diluted in 200 ml of warm. This elixir is drunk before going to bed. Instead of such a drink, you can do steam inhalation with soda. A tablespoon of powder is diluted in a liter hot water and breathe over it. To enhance the effect, you can add a few drops to the solution. essential oils eucalyptus, pine or. Gargling with a solution of salt and soda relieve inflammation of the tonsils with tonsillitis.
Intravenous administration of a sterile aqueous solution of sodium bicarbonate is often used in intensive care, infectious diseases and toxicology for poisoning, intoxication. metabolic acidosis.
Use in cooking
The use of sodium bicarbonate is also multifaceted in cooking. The ability of soda to release carbon dioxide when quenched with vinegar allows it to be used as a baking powder. Slaked soda gives splendor to omelet, dough. You can extinguish soda with vinegar or add powder to sour cream or kefir dough. In the second case, lactic acid will play the role of vinegar.
Adding it to bean dishes can reduce the cooking time. Using baking soda in a meat marinade can soften tough muscle fibers. Berry and fruit mousses, when a pinch of soda is added to them, become sweeter, and more transparent and fragrant.
In order to get rid of nitrates in vegetables, they need to be soaked in a soda solution. Darkened can be lightened in the same way.
Application in the economy
The substance is indispensable in everyday life. It is an excellent cleanser. To restore their shine, chrome-plated items and silverware are rubbed with dry soda, washed with soapy water, and then wiped dry with a soft cloth.
Sodium bicarbonate powder applied to a moistened sponge removes scratches and scuffs from vinyl flooring. Tiles, stoves, sinks and plumbing can be cleaned of dirt by treating with a thick mixture of soda and water. The same mixture helps to get rid of the specific cat smell in places where there were “marks”.
To remove odors
The good hygroscopicity of sodium bicarbonate is the reason why it quickly absorbs odors, so it can be used to eliminate various odors. To get rid of unpleasant odors in the refrigerator, you need to pour dry powder into a glass and put it in the refrigerator door. By changing the contents of the glass as needed (every 1-2 months), you can permanently get rid of the specific "refrigeration" smell.
With persistent odor sour milk"Smelling" containers should be cleaned with a dry powder. Do the same with dishes that have the smell of fish.
If you pour a few tablespoons of powder into the drain hole, and turn on warm water after a few minutes, you can eliminate the unpleasant smell from the siphon under the sink.
Baking soda will also help to deal with the unpleasant smell from the carpet. To do this, the carpet is sprinkled with powder, left for 20-30 minutes, and then thoroughly vacuumed. However, this method is only suitable for non-shedding carpets.
Baking soda can also be used to prevent unpleasant odors from, for example, washing or dishwasher during their long periods of inactivity. Leaving for long time from home, rub with dry bicarbonate inner surface machines and leave their doors ajar, and after returning, start them in rinsing mode.
For clothes care
During machine washing, it will be good to add to washing powder soda. This will help get rid of the unpleasant smell in the washing machine, improve the quality of washing and the aroma of the washed laundry. Unpleasantly smelling clothes can be washed in the washing machine, sprinkled liberally with baking soda.
A wet swimsuit will not get moldy and will not smell unpleasant if, after swimming in a pool or in a natural reservoir, it is folded into a bag with soda, and rinsed and dried thoroughly at home.
Use in cosmetology
soda is great cosmetic product. A good cleansing and whitening effect has a scrub made from crushed oatmeal and dry sodium bicarbonate. The skin after such a scrub becomes soft, and its regular use eliminates acne. To add shine to the hair after washing the head, they must be treated with a solution of soda and.
For weight loss
Sodium bicarbonate is also used for weight loss. To lose up to 2 kg in one procedure, you can fill the bath with warm water and dissolve 0.5 kg and 0.3 kg of ordinary baking soda in it. Losing weight need to immerse yourself in such a bath for 20 minutes. In this case, the water temperature should be about 40 ° C. Soda-salt solution relaxes muscles, relieves fatigue and nervous tension, cleans lymphatic vessels, reduces tissue swelling. After the bath, you should not wipe yourself: just put on a warm bathrobe. Do such water procedures better before bed.
Other uses
Irreplaceable soda in campaigns. She can:
- wash dishes without harming the environment;
- replace toothpaste;
- put out the fire;
- lubricate the skin in places of insect bites.
You can get rid of the unpleasant smell from shoes if you rub it from the inside with dry soda or moisten it with a soda solution. A mixture of sodium bicarbonate and sugar kills cockroaches.
Industrial use
Baking soda as a food additive E500 is used by the food industry in the manufacture of bakery, flour, confectionery, sausage products, carbonated drinks, as well as for cleaning industrial equipment.
The chemical industry uses sodium bicarbonate in the production of dyes, reagents, household chemicals, foam plastics. Powder fire extinguishers are filled with bicarbonate.
In light industry, soda is used in the leather industry, for the manufacture of artificial leather, silk and cotton fabrics.
How to choose and store
Sodium bicarbonate should be stored in closed packs so as not to accumulate odors. Before buying, you must shake the pack of soda. If fine dust falls out of it, this is a sign of staleness of the product and partial decomposition of the compound inside the pack. At home, immediately pour the powder into an airtight container.
Soda should be stored in dry, ventilated areas, away from strong-smelling products. The storage temperature is not limited, however, it must be remembered that the higher it is, the faster product loses its properties. The guaranteed shelf life is 12 months, but if soda has been stored correctly and has not lost its reactivity, its shelf life is not limited.
You can check the reactivity of bicarbonate in a simple way: when extinguishing a pinch of soda with vinegar, foam will form from gas bubbles.
Expanding the range of application of soda in household, every housewife can save her budget and discover many environmentally friendly and hypoallergenic products for cleaning, washing and much more.
For many years, crystal soda has attracted increased attention of scientists. Specialists involved in the study of this component are finding more and more new areas of its application. However, it is not a secret for anyone that such discoveries require certain knowledge, and, first of all, from the field of chemistry. Let's talk a little more about the chemical properties that characterize this natural substance.
Crystalline soda is nothing more than the same baking soda that we use in cooking - most of the people probably have such an idea. However, this is not entirely true. In fact, the concept of "crystal soda" serves to refer to sodium salts of carbonic acid and is their common name. Depending on the type of connection, 3 main varieties are distinguished.
- Drinking or baking soda, which is a white fine crystalline powder that is practically odorless. The main name of this component is bicarbonate or sodium bicarbonate.
- Soda ash is a crystalline substance that is characterized by a white color or does not have it at all.
- Caustic soda is the most common type of alkali, represented by white granules that are odorless, but are characterized by the ability to dissolve perfectly in water and release heat at the same time.
Crystalline soda is a mineral, its deposits can be found in lakes, the waters of which are so rich in this raw material that the substance accumulates on the banks and forms real snowdrifts. A prime example such unusual reservoirs are lakes in Western Siberia and Transbaikalia, in Tanzania and California. Mining of the mineral is also carried out in mines, and in ancient times, crystalline soda was obtained from seaweed Solyanka sodoniferous - it was from these words that the name of the substance came from. In 1961, thanks to the scientific developments of the Belgian chemist Ernest Gaston Solvay, this natural component began to be obtained industrially, by the way, the principles and technologies of this method are still used today.
Chemical formula
Sodium salts of carbonic acid are expressed by different chemical formulas and are characterized by a set of properties that differ from each other depending on the type of substance.
So, baking soda has the designation NaHCO3, it dissolves perfectly in water, but it does not have the ability to burn. During the heating process, when the temperature exceeds 70 C, the powder begins to decompose into sodium carbonate, carbon dioxide and water.
The formula Na2CO3 is used to fix soda ash. Just like sodium bicarbonate, this type of salt is characterized by its insolubility in ethanol and acetone, however, this substance is completely soluble in water, while the higher the temperature of the liquid, the greater the concentration formed. As a result of this process, the hydroxyl group of the compound begins to interact with sodium, which leads to the production of caustic soda, caustic soda (NaOH), which is used as a cleaning agent. A distinctive property of soda ash is the ability to absorb water vapor, which explains its caking in the open air into dense lumps.
Crystalline soda is generally inherent general formula- Na2CO3, but a more accurate notation is as follows: Na2CO3-10H2O.
Substance use
Thanks to scientific research, many ways of using crystalline soda were discovered, in connection with which this substance can rightly be called universal remedy. Most wide application soda received in the industrial sphere, in everyday life and cooking, in medicine and cosmetology.
The industrial branch gives its preference to caustic soda, it is there that this substance is used for the following purposes:
- to give purity to tissues;
- for the production of paper and cardboard;
- for the purification of petroleum products and the manufacture of oil products;
- to neutralize toxic gases;
- to strengthen the foundation of buildings under construction;
- for cleaning equipment of industrial enterprises;
- for degreasing tools;
- to create cosmetics.
Any type of crystalline soda is traditional means used at home as a cleaner from various kinds of pollution. So, with the help of this substance, you can remove stains from tiles, sinks, plumbing, dishes or carpets. Some modern powders can destroy the surface of linoleum, marble, shells made of artificial stone with their aggressive effect, but this phenomenon does not apply to crystalline soda. In addition, you can easily get rid of scale on the heating elements of the washing machine, and in this case, soda ash is most suitable. Eliminate blockages in sewer pipes, get rid of unpleasant odors in the refrigerator, bleach bed linen - all these are problems that crystal soda, which is a real helper for every housewife, can also solve.
In the field of cosmetology, drinking soda is mainly used, its use allows solving the following problems:
- lose extra pounds;
- eliminate dead skin cells;
- eliminate acne and acne;
- get rid of puffiness under the eyes:
- remove oily sheen from the face, reduce oily hair.
In addition, you can treat makeup or manicure tools with a soda solution - this will not only clean them of dirt, but also remove germs from surfaces.
Due to its ability to destroy bacteria and pathogenic microorganisms, soda is used in medicine for the treatment various diseases caused by similar pathogens, however, the use of powder is also known in the treatment of certain independent diseases, as well as their concomitant symptoms.
In this area, crystal soda and, in particular, food performs a number of specific tasks:
- relieves fungal diseases: thrush, onychomycosis;
- eliminates heartburn;
- reduces swelling and itching from insect bites or when an allergic reaction occurs;
- removes pain syndrome with burns and promotes rapid tissue regeneration;
- restores the fluid lost by the body in case of poisoning, prevents dehydration;
- relieves infections localized in the oral cavity;
- fights with urolithiasis;
- prevents caries;
- whitens tooth enamel.
And, of course, the most famous use of crystal soda is still its use in cooking. However, only baking soda, that is, sodium bicarbonate, can be involved in this area, since it is this substance that is characterized by a weak alkaline reaction. Due to the origin of the reaction of sodium bicarbonate with an acidic environment, carbon dioxide is released, giving confectionery products or, for example, scrambled eggs a loose, porous structure and a magnificent appearance.
Molar mass
Crystalline soda, formed by a sodium cation and an anion of carbonic acid, has a molecular weight of 106 atomic units. This indicator is calculated from the sum of the masses chemical elements- sodium, oxygen and carbon atoms. The molar mass of the substance is 105.99 g / mol, which is almost identical to the molecular weight.
Sodium salts of carbonic acid occupy an important place in human life. Due to the chemical properties, due to which the process of hydrolysis and the formation of an alkaline reaction of water, crystalline soda finds its application in various fields, which makes it a very unique tool.
Sometimes a completely ordinary and familiar substance from childhood turns out to be almost a panacea for many diseases and ailments. Just not everyone knows it. One of these compounds is the usual one stored in everyone's kitchen cabinet. It turns out that it serves not only as a means to improve the quality of baking, but also as a medicine, degreaser, bleach, and even a disinfectant. Let's get acquainted with this substance in more detail.
The chemical base of soda
The correct name for this compound in terms of chemistry is sodium bicarbonate. There are a number of names that are used in everyday life and chemistry to refer to this substance:
- bicarbonate of soda;
- baking soda;
- drinking soda;
- sodium bicarbonate;
- additive E 500.
However, any of them reflects the only true essence - this is soda.
Empirical formula
The formula for baking soda is NaHCO 3 . That is, by its nature, this substance is related to the category of acidic. Since the compound is formed by a strong alkali and a weak acid, during hydrolysis (in aqueous solution) will be an alkaline reaction of the medium. A solution of baking soda in water has a pH of 8.1. is easily formed by the interaction of carbonic acid, the process is expressed by the following reaction equation:
NaOH + H 2 CO 3 \u003d NaHCO 3 + H 2 O
The empirical formula of baking soda shows the quantitative and qualitative composition of the compound, on the basis of which it is possible to draw a conclusion about the spatial structure of the molecule: a positively charged Na + cation in the outer sphere and a negatively charged HCO 3 hydrocarbonate ion in the inner one.
The carbon atom coordinates around itself three oxygen atoms, with one of which it forms a double bond. Also, one of the oxygen atoms combines with a hydrogen cation, forming a hydroxo group. The third oxygen atom in the form of an ion is associated near the sodium cation. Thus, the valencies of each element that is part of this compound are compensated.
Physical properties
Whatever name we give this substance - baking soda, drinking, carbonate, sodium bicarbonate - its formula is still the same and gives an idea of So, appearance soda - fine powder. Its coloration is white. Let's well dissolve in water and it is practically insoluble in organic solvents (alcohol, for example). Does not decompose in the open air. Starts to disintegrate at high humidity environment. The products of complete decomposition with increasing temperature are sodium carbonate (medium salt), carbon dioxide and water:
NaHCO 3 \u003d Na 2 CO 3 + CO 2 + H 2 O
Sodium bicarbonate is odorless, tastes slightly salty, with a touch of alkali. When dissolved in water, it gives alkaline solutions of various concentrations.
Brief information about the history of the discovery and use of soda
The first information about sodium bicarbonate appeared in ancient civilization Egypt. It was in those parts that several lakes containing natural sources of soda were distributed. When these lakes dried up, they gave out soda in the form of a white powder, and people collected it. It was used by the Egyptians as one of the components in the manufacture of mummification tools. The formula for baking soda was not yet known at that time.
Specifically, as a chemical compound, the substance was studied much later, around the 18th century. It was then that scientists became interested in this powder, formed naturally. A thorough analysis of the composition made it possible to determine the qualitative and quantitative components of the compound. This is how the modern baking soda formula was born.
A great contribution to the development of ideas about the substance and its properties was made by the Italian physician Tullio Simoncini. He owns experiments, according to the results of which soda - possible variant cancer treatment. However, to date, there is no exact data confirming this.
Areas of use
Due to its ability to dissolve well in water, as well as interact with acids, forming carbon dioxide as a result of the reaction, soda is used in several areas of industry and everyday life. Namely, such as:
- pharmaceuticals and medicine;
- chemical industry;
- light industry;
- food industry.
Let's consider in more detail each of the directions.
Application in medicine
The main thing on which the use of a substance in medicine is based is its ability to restore the water-alkaline balance in the gastrointestinal tract. The NaHCO 3 compound belongs to antacids treatment. The baking soda formula indicates the presence of hydroxide ions, which perform the function of neutralizing hyperacidity in the body. Therefore, most often a solution of sodium bicarbonate in water is used to eliminate the symptoms of heartburn. However, this is not the only area of diseases where the substance can be used.
- During treatment colds baking soda relieves cough, as it helps to thin and remove sputum from the lungs and bronchi. Also with it you can do inhalation with SARS.
- Baking soda is also used as a bactericidal and anti-inflammatory agent. Its formula reflects the presence of hydrogen cations H + , which provide this effect.
- For treatment cardiovascular diseases(arrhythmias and hypertension) a weak solution of sodium bicarbonate in water is used.
- With diarrhea and vomiting, the use of soda together with salt allows you to replenish the body's water supply and restore the necessary balance.
- The substance is capable of destroying fungal diseases, therefore, it is used to eliminate the fungus of the foot, douching with a solution for thrush, and washing the eyes for inflammation of the conjunctiva.
- Due to its whitening properties, baking soda is used for brushing teeth.
- A weak solution allows you to get rid of itching when skin rashes(or insect bites).
- Treatment of primary burns.
- Exemption of the body from salts of heavy metals.
- Fatigue occurs, as well as getting rid of excess weight when using a warm bath with NaHCO 3 and essential oils.
About the benefits and harms of baking soda when used in medical purposes, including in cosmetology, you can say a lot. The main rule of application this tool, like any other medicine - do not neglect the dosage recommendations. Improper use may be harmful to health.
Baking soda: formula and use in the chemical industry
The main area in which sodium bicarbonate is used is household chemicals. Baking soda can act as a mild abrasive for cleaning and degreasing surfaces. It is also used as a raw material in the production of dyes, foams and fluorine compounds. In addition, fire extinguishing agents are made on the basis of NaHCO 3.
It is impossible to imagine how household chemicals would develop without sodium bicarbonate. Baking soda is an important and necessary component for many chemical syntheses.
Light industry
Baking soda is used for surface treatment in the manufacture of rubber, rubber soles and products. The formula, application, harm and benefits of sodium bicarbonate in light industry is a separate topic for study. In short, the role of NaHCO 3 is reduced to use in the production of textiles and artificial leather. In this case, the harm manifests itself in the appearance of burns if contact with the substance occurred for too long and the hands were not protected. The benefit is that soda is an excellent additive and degreaser in leather tanning and production, as well as a good fabric bleach in the textile business.
food industry
The formula of baking soda in chemistry reflects the essence of the processes in reactions with acids. For example, with acetic acid interaction will be described by the following equation:
NaHCO 3 + CH 3 COOH \u003d CH 3 COONa + H 2 CO 3
In this case, the formed carbonic acid, being very unstable, immediately decomposes into CO 2 and H 2 O. It is on this feature of the course of reactions that the use of sodium bicarbonate in Food Industry. Indeed, for the manufacture of baking, it is necessary to extinguish the soda with vinegar, add the resulting mixture to the dough for its porosity and better structure. The soda quenching reaction is of the type and is accompanied by a spectacular effect of foaming and hissing.
The use of soda makes baking very soft, fragrant and beautiful, so the food industry is one of the main industries where this substance is used on a large scale. Sodium bicarbonate is also used in baking, in the manufacture of various confectionery products. In addition, it is also used to form gas bubbles in fizzy drinks (carbonated water, champagne and sparkling wines, mineral water).
Baking soda: properties and treatment. Harm and contraindications for use
In fact, the use of soda is quite wide in various industries and households, as we could see earlier. Its unusual healing, antibacterial, whitening, soothing and healing properties are used in the treatment various ailments. However, like any other medicine, soda also has an opposite side. It can be harmful and very dangerous to health. Its indications for use are obvious, but no less important are the contraindications, which we will consider in more detail.
Harm and contraindications for use
There are several main reasons why soda can become an enemy, and not a friend and helper.
Therefore, it is obvious that baking soda plays not only a positive role for a person. Benefit and harm, treatment are ambiguous aspects. Before using sodium bicarbonate everywhere to get rid of various ailments, you should consult your doctor. If soda is used in everyday life (cleaning surfaces, bleaching fabrics, and so on), then do not neglect the most simple means protection for non-contact use of the substance.
DEFINITION
sodium bicarbonate(baking soda, Bulrich's salt) is an acidic salt of carbonic acid.
Under normal conditions, sodium bicarbonate is a solid white color(Fig. 1), which decomposes upon weak heating. When wet, it begins to decompose at room temperature. Moderately soluble in water (hydrolyzed by the anion). It does not form crystalline hydrates.
Rice. 1. Sodium bicarbonate. Appearance.
Chemical formula of sodium bicarbonate
Chemical formula of sodium bicarbonate NaHCO 3 . It shows that this molecule contains one sodium atom (Ar = 23 a.m.u.), one hydrogen atom (Ar = 1 a.m.u.), one carbon atom (Ar = 12 a.u. m) and three oxygen atoms (Ar = 16 amu). According to the chemical formula, you can calculate the molecular weight of sodium bicarbonate:
Mr(NaHCO 3) = Ar(Na) + Ar(H) + Ar(C) + 3×Ar(O);
Mr(NaHCO 3) = 23 + 1 + 12+ 3×16= 44 + 48 = 92
Graphical (structural) formula of sodium bicarbonate
The structural (graphical) formula of sodium bicarbonate is more visual. It shows how atoms are connected to each other within a molecule:
Ionic formula
Sodium bicarbonate is an acid salt of carbonic acid, which undergoes dissociation in aqueous solution according to the following reaction equation:
NaHCO 3 ↔ Na + + HCO 3 -
Examples of problem solving
EXAMPLE 1
| Exercise | The mass fraction of chlorine in phosphorus chloride is 77.5%. Determine the simplest compound formula. |
| Solution | The mass fraction of the element X in the molecule of the HX composition is calculated by the following formula: ω (X) = n × Ar (X) / M (HX) × 100% Calculate the mass fraction of phosphorus in the compound: ω(P) = 100% - ω(Cl) = 100% - 77.5% = 22.5% Let us denote the number of moles of elements that make up the compound by "x" (phosphorus) and "y" (chlorine). Then, the molar ratio will look like this (values of relative atomic masses taken from the Periodic Table of D.I. Mendeleev, rounded up to integers): x:y = ω(P)/Ar(P) : ω(Cl)/Ar(Cl); x:y= 22.5/31: 77.5/35.5; x:y= 0.726: 2.183 = 1: 3 So the formula for the compound of phosphorus with chlorine will be PCl 3. It is phosphorus(III) chloride. |
| Answer | PCl 3 |
EXAMPLE 2
| Exercise | A sample of a compound of phosphorus and bromine weighing 81.3 g contains 0.3 mol of phosphorus. Find the empirical formula of the compound. |
| Solution | Calculate the mass of phosphorus in the compound (the relative atomic mass is 31 amu and numerically coincides with the values of the molecular and molar masses): m(P) = n(P) × M(P); m(P) = 0.3 × 31 = 9.3 g Determine the mass of bromine in the composition of the compound: m(Br) = m substance - m(P); m(Br) = 81.3 - 9.3 = 72 g Let us denote the number of moles of elements that make up the compound as "x" (phosphorus) and "y" (bromine). Then, the molar ratio will look like this (the values of relative atomic masses taken from the Periodic Table of D.I. Mendeleev will be rounded to integers): x:y = m(P)/Ar(P) : m(Br)/Ar(Br); x:y= 9.3/31: 72/80; x:y= 0.3: 0.9 = 1: 3 So the formula for the compound of phosphorus and bromine will look like PBr 3. |
| Answer | PBr 3 |
A distinctive feature is the mild alkaline properties that do not have a harmful effect on animal and plant tissues.
Density - 2.159 g / cm³. Boiling point - 851° C, melting point - 270° C.
In nature, soda is found in solid form in small deposits as part of the throne mineral, in the form of a solution in the water of some soda lakes and alkaline mineral springs, and in the ashes of some plants. In industry, baking soda is obtained as an intermediate product in the production of soda ash using the ammonia method (the so-called Solvay process).
Application of baking soda.
Baking soda is widely used in various industries, National economy and in everyday life. Used in chemical, food, light, medical, pharmaceutical industry, non-ferrous metallurgy, etc.
In the food industry, it is registered as food supplement E500. The main application is cooking, baking, confectionery production, where it is used mainly as the main or additional baking powder in baking, alone or as part of complex baking powder and in ready mixes for baking. It is also used in the production of carbonated drinks.
In medicine, a solution of baking soda is used as a weak antiseptic for rinsing, as well as a traditional acid-neutralizing remedy for heartburn and stomach pain.
In the chemical industry, it is used for the production of dyes, foams and other organic products, fluorine reagents, household chemicals, fillers in fire extinguishers, for separating carbon dioxide, hydrogen sulfide from gas mixtures. It is also included in the composition of the powder used in powder fire extinguishing systems, utilizing heat and displacing oxygen from the combustion source with the emitted carbon dioxide.
In light industry, sodium bicarbonate is used in the production of sole rubber and artificial leather, leather production (tanning and neutralization of leather), textile industry (finishing silk and cotton fabrics).
In everyday life it is used as an excellent tool for cleaning, washing and removing stains and scale. Baking soda is great for removing unpleasant odors, refreshes and cleans carpets, removes the musty smell of old books. AT medicinal purposes baking soda is used for burns, including sunburn. She is an ambulance and with a bee or wasp sting.
| Name of indicator | The norm for the variety | ||
| The first | Second | ||
| Appearance | White crystalline powder, odorless | ||
| Mass fraction of sodium bicarbonate (NaHCO 3), %, not less than** | 99,5 | 99,0 | |
| Mass fraction of sodium carbonate (Na 2 CO 3),%, not more than** | 0,4 | 0,7 | |
| Mass fraction of chlorides in terms of NaCl, %, not more than** | 0,02 | 0,04 | |
| Mass fraction of arsenic (As),%, no more | Withstands the test | ||
| Mass fraction of water-insoluble substances, %, no more | Withstands the test | ||
| Mass fraction of iron (Fe 2+),%, not more than** | 0,001 | 0,005 | |
| Mass fraction of calcium (Ca 2+),%, no more | 0,04 | 0,05 | |
| Mass fraction of sulfates in terms of SO 4 2-,%, no more | 0,02 | 0,02 | |
| Mass fraction of moisture, %, no more | 0,1 | 0,2 | |
Safety requirements for baking soda.
Baking soda is non-toxic, fire and explosion-proof, according to the degree of impact on the body, it belongs to substances of the 3rd hazard class. The maximum allowable concentration of sodium bicarbonate in the air of the working area is 5 mg/m³.
| Degree of toxicity | - |
| Main properties and types of danger | |
| Basic properties | Fine-crystalline powder of white color, odorless. |
| Explosion and fire hazard | Fire and explosion proof. Non-combustible May decompose when heated to form toxic gases. Containers may explode when heated. |
| Human danger | Baking soda is dangerous in contact with skin and eyes. Causes irritation on contact with mucous membranes. Continuous operation in an atmosphere contaminated with sodium bicarbonate dust may cause irritation. respiratory tract. In case of fire, burns are possible. |
| Individual protection means | Protective overall suit L-1 or L-2 complete with industrial gas mask with cartridges A, B. Oil and gasoline resistant gloves, special footwear. In case of fire - fire-retardant suit complete with SPI-20 self-rescuer. Overalls, safety devices. |
| Necessary actions in emergency situations | |
| General | Take the wagon to a safe place. Isolate danger zone within a radius of at least 100 m. Adjust the indicated distance according to the results of chemical exploration. Remove strangers. Comply with measures fire safety. Do not smoke. Provide first aid to the injured. |
| In case of leakage, spill and placer | Report to CSEN. Do not touch spilled or spilled material. Do not allow the substance to enter waterways, basements, sewers. |
| In case of fire | Enter the accident zone in protective clothing and breathing apparatus. Extinguish with water mist, air-mechanical foam from a maximum distance. |
| Neutralization | Cover with sand or other inert material. Burn the area (individual outbreaks) if there is a threat of getting into groundwater. Call experts for neutralization. |
| First aid measures | summon ambulance. Fresh air, peace, warmth, clean clothes. Flush eyes and mucous membranes with water for at least 15 minutes. |
Packing, transportation and storage.
Baking soda is packed in four-layer or five-layer paper bags weighing up to 50 kg or in specialized disposable containers of the MKR-1.0 type with a polyethylene liner, weighing no more than 1 ton. Sodium bicarbonate (sodium bicarbonate), intended for retail, packed in consumer packaging - cardboard packs weighing 500 and 1000 g, plastic bags weighing 500 g.
Baking soda is transported by all modes of transport (except air) in covered vehicles in accordance with the rules for the carriage of goods in force on this type of transport. It is allowed to transport sodium bicarbonate by road in bulk using specialized transport (such as a flour truck) or in specially made stainless steel containers. Specialized flexible containers are transported by railway open rolling stock wagon shipments without transshipment, with loading and unloading on the consignor's (consignee's) sidings.
Baking soda is stored in closed warehouses. Filled specialized soft containers and transport packages are stored both in covered warehouses and in open areas, in 2-3 tiers in height.
Guaranteed shelf life of the product - 12 months from the date of manufacture.