Acid or alkali - which is healthier for humans? Acid and alkali are the eternal struggle of opposites.

The word "acid" comes from the Latin word for "sour." Some products from our table, for example, vinegar or lemon juice, are acids. A base is a compound that is chemically opposite to an acid and, when reacted with an acid, produces a neutral compound - . Bases soluble in water are called alkalis. Citrus fruits - grapefruits, oranges and lemons - contain citric and ascorbic acids. Bee venom is acidic. It can be neutralized with a base. Citrus fruits - grapefruits, oranges, lemons - contain citric and ascorbic acids.

Acids

Acids are compounds that contain and produce hydrogen ions (H+) when dissolved in. Ions are particles with an electrical charge (see article “”). It is the ions that give acids their properties, but they can only exist in solution. Consequently, the properties of acids appear exclusively in solutions. The sulfuric acid molecule (H 2 SO 4) consists of hydrogen, sulfur and oxygen. Hydrochloric acid (HCl) contains hydrogen and chlorine. An acid is considered strong if most of its molecules disintegrate in solution, releasing hydrogen ions. Hydrochloric, sulfuric, and nitric acids are strong. The strength of an acid is measured by the pH number - pH value. Strong acids are very aggressive; Once on the surface of an object or on the skin, they burn through it. Containers containing strong acids are labeled with internationally accepted symbols meaning “dangerous” and “high potency.”

Acids such as citric or acetic, i.e. produced by living organisms are called organic. Acids are widely used in the chemical and medical industries, in the production of food and synthetic fibers. Grape vinegar contains a weak acid called acetic acid. Tomatoes contain organic salicylic acid. The colored spots on the skin of sea snails contain an unpleasant-tasting acid that repels predators. All acids exhibit similar behavior in . For example, when acids react with bases, a neutral compound is formed - salt and water. Reactions of acids with most produce salt and hydrogen. Reacting with carbonates, acids produce salt, carbon dioxide and water. Baking powder known to culinary experts contains sodium bicarbonate and tartaric acid. When water is added to flour containing baking powder, the acid and carbonate in the powder react, causing carbon dioxide to bubble up and help the dough rise.

Bases and alkalis

A base is a compound that is the chemical opposite of an acid. An alkali is a base that is soluble in water. When mixed with an acid, the base neutralizes its properties, and the reaction product is a salt. Toothpaste is a base that neutralizes the acid remaining in the mouth after eating. Household liquid cleaners contain alkalis that dissolve dirt. Stomach tablets contain alkalis that neutralize the acid that circulates during indigestion. From a chemistry point of view, bases are substances that can add hydrogen ions (H+) from an acid. Oxide ion (O 2-) and hydroxide ion (OH -) can combine with hydrogen ions in an acid. This means that metal oxides, such as magnesium oxide, and metal hydroxides, such as sodium hydroxide (caustic soda), are bases. Sodium hydroxide (NaOH) consists of sodium, oxygen and hydrogen. Magnesium hydroxide (Mg(OH) 2) consists of magnesium, oxygen and hydrogen.

Many bases and alkalis are very caustic substances and therefore dangerous: they corrode living things. Liquid cleaners contain alkalis that dissolve dirt. In the paper industry, sodium hydroxide dissolves tree resin and releases the cellulose fibers from which paper is made. Sodium hydroxide (caustic soda) is used in cleaning fluids and (like potassium hydroxide) to make soap. Soap is a salt formed by the reaction of alkalis with acids of vegetable fats. The wasp's sting releases an alkali that can be neutralized with an acid such as vinegar.

pH and indicators

The strength of acids and bases is determined by the pH number. It is a measure of the concentration of hydrogen ions in a solution. The pH number varies from 0 to 14. The lower the pH, the higher the concentration of hydrogen ions. A solution whose pH is less than 7 is an acid. Orange juice has a pH of 4, which means it is acidic. Substances with pH = 7 are neutral, and substances with pH greater than 7 are bases or alkalis. The pH of an acid or alkali can be determined using an indicator. An indicator is a substance that changes color when in contact with an acid or alkali. So litmus turns red in acid and blue in alkali. Acid turns blue litmus paper red, and red litmus paper in alkali turns blue or purple. Litmus is obtained from primitive plants called lichens. Other plants, such as hydrangea and red cabbage, are also natural indicators.

The so-called universal indicator is a mixture of several colors. It changes color depending on the pH of the substance. It turns red, orange or yellow in acids, green or yellow in neutral solutions and blue or purple in alkalis.

Sulfuric acid

Sulfuric acid plays an important role in industry, primarily in the production of fertilizers based on superphosphates and ammonium sulfate. It is also used in the production of synthetic fibers, dyes, plastics, drugs, explosives, detergents, and car batteries. Sulfuric acid was once called mineral acid, since it was obtained from sulfur, a substance found in the earth’s crust in the form of a mineral. Sulfuric acid is very active and aggressive. When dissolved in water, it releases a lot of heat, so it must be poured into water, but not vice versa - then the acid will dissolve and the water will absorb the heat. It is a powerful oxidizing agent, i.e. During oxidation reactions, it gives oxygen to other substances. Sulfuric acid is also a desiccant, i.e. takes up water bound to another substance. When sugar (C 12 H 22 O 11) is dissolved in concentrated sulfuric acid, the acid takes away the water from the sugar, leaving the sugar as a foaming mass of black coal.

Acids in soil

The acidity of the soil depends on the nature of the rocks that formed it and on the plants growing on it. On chalk and limestone rocks the soil is usually alkaline, while on meadows, sandy and wooded areas it is more acidic. Acidity is also increased by acid rain. Neutral or slightly acidic soils with a pH of 6.5 to 7 are best suited for farming. As dead leaves decompose, they form organic humic acid and increase the acidity of the soil. Where the soils are too acidic, crushed limestone or slaked lime (calcium hydroxide) is added to them, i.e. bases that neutralize soil acids. Plants such as rhododendrons and azaleas grow well in acidic soils. Hydrangea flowers are blue in acidic soil, and pink in alkaline soil. Hydrangea is a natural indicator. On acidic soils its flowers are blue, and on alkaline soils they are pink.

Acid and alkali - the eternal struggle of opposites

Few people know, but the predominance of acid or alkali in the human body will determine what diseases a person will be predisposed to. The pH of the blood of a healthy person, according to the latest medical research, is 7.8, which indicates the predominance of alkali in the body. Such a person will avoid colds. Why? Yes, because colds and inflammatory processes are always an acidic environment. Bacteria that cause colds can multiply exclusively in an acidic environment, and when they get into an alkaline environment, they die safely. For example, laundry soap has been the number one enemy for all types of bacteria for many years and is used to “alkalize” the surface of the hands before eating. Or during a cold we drink hot milk with honey - milk and honey are alkaline products; when they enter the body, they increase alkalinity and promote recovery. Lemon tea is also an alkaline solution (especially if not sweetened), which is also used during colds.

But then what about acid? Maybe we don’t need it at all? We need acid for healthy digestion. If a person does not have an acidic environment in his stomach, then the process of digesting food will turn into flour. Intestinal dysbiosis is the result of a violation of acidity in the stomach, which entails serious digestive problems and is fraught with the development of chronic intestinal diseases.

So, we have found out that for health a person needs not only alkali, but also acid. Now let's look at the results of the predominance of acid and alkali in the body and methods for eliminating such deviations. The main factor in the formation of a person’s internal environment is diet. There are “sour” foods, that is, those whose consumption increases the acidity of the body, and “alkaline” foods, which increase the alkalinity of the internal environment of the body. Sour foods include: meat and meat products, fermented milk products, fish, sugar, eggs, baked goods, beer. A human diet constantly consisting of the above products will ultimately lead to a decrease in immunity and the development of chronic inflammatory diseases, such as bronchitis, pancreatitis, gastritis with high acidity, prostatitis, sinusitis, cystitis, pyelonephritis, and other diseases associated with inflammatory processes. Such a person often catches a cold, “all the drafts are his.” The body does not have time to cope with the huge amount of incoming lactic and other types of acids; it accumulates in the organs, and chronic inflammatory diseases begin to develop there. In men, the predominance of acid leads to infertility and impotence, since sperm can only survive in an alkaline environment. Increased acidity of the body reduces the activity of living creatures, which leads to male infertility, and subsequently to impotence. In women, increased acidity of the body also threatens the development of inflammatory processes, excess weight and leads to infertility. In this case, the acidity of the vagina increases (in the normal state it is slightly acidic), and sperm entering the woman die before reaching the uterus. And if sperm motility is reduced by the increased acidity of a man’s body, then conception is out of the question. Of course, the reason described is not the only one why currently reproductive function decreases in men and women. The demographic problems of modern Russia and the world as a whole need to be considered holistically, but close attention should be paid to the issue of healthy nutrition for the nation.

However, if a person eats exclusively alkaline foods, and these include vegetables (fresh and in salads seasoned with vegetable oils), fruits, cereals, whole milk, honey, red and white dry wine, canned vegetables, then this leads to excess calcium in the body and the development of joint diseases, salt deposition, which, in turn, can cause diseases of the cardiovascular system, urolithiasis, the appearance of stones in the liver, kidneys, and gall bladder. As we see, a balanced diet is necessary for human health.

To summarize: for human health, the diet must contain both animal products of “sour” origin and plant products. Throughout the year, it is necessary to change the diet so that excess acid or alkali does not accumulate in the body. A person’s daily menu must change constantly; constancy and maximalism in the diet must be avoided. Constantly eating the same foods leads to the development of chronic diseases.

In conclusion, I would like to draw special attention to men who consider meat and meat products to be real “male” food. Excess lactic acid, which meat is rich in, in a man’s body leads to infertility and impotence. Therefore, next time, before telling your wife: “What am I, a rabbit, or something, to eat your carrot salad! Meat is the food of a real man!” – remember the fertility of the latter and the fact that an exclusively meat diet is a direct path to infertility and impotence. If you want to be healthy, maintain your acid-base balance.

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Alkali (synonym - alkali) is the name of any of the soluble hydroxides of alkali metals, that is, lithium, sodium, potassium, rubidium and cesium. Alkalis are strong bases and react with acids to produce neutral salts. They are caustic and, in concentrated form, are corrosive to organic tissue. The term alkali is also applied to soluble hydroxides of the alkaline earth metals such as calcium, strontium and barium, as well as ammonium hydroxide. The name of the substance, alkali, was originally applied to the ashes of burned plants containing sodium or potassium, from which oxides of sodium or potassium could be leached.

Among all alkalis produced by industry, the largest share of such production is accounted for by the production of soda ash (Na2CO3 - sodium carbonate) and caustic soda (NaOH - sodium hydroxide). The next alkalis in terms of production volume are potassium hydroxide (KOH-caustic potash) and magnesium hydroxide (Mg(OH)2-magnesium hydrate).

The production of a wide range of consumer products depends on the use of alkalis at some stage. Soda ash and caustic soda are important in the production of glass, soap, rayon, cellophane, paper, cellulose, detergents, textiles, water softeners, some metals (especially aluminum), bicarbonate of soda, gasoline and many other petroleum products and chemicals. .

A few historical moments from the history of alkali production.

People have been using alkali for centuries, obtaining it first from leaching (aqueous solutions) of certain desert lands. Until the late 18th century, leaching from wood ash or seaweed was the main source of alkalis. In 1775, the French Academy of Sciences offered cash prizes for new production methods alkalis. The Soda Ash Prize was awarded to the Frenchman Nicolas Leblanc, who in 1791 patented a process for converting sodium chloride into sodium carbonate.

The Leblanc method of production dominated world production until the end of the 19th century, but after the First World War it was completely replaced by another method of salt conversion, which was improved in the 1860s by Ernest Solvay of Belgium. At the end of the 19th century, electrolytic methods for the production of caustic soda appeared, the volumes of which grew rapidly.

According to the Solvay method, the ammonia-soda process for the production of soda ash proceeded as follows: table salt in the form of a strong brine was chemically treated to eliminate calcium and magnesium impurities and then saturated with recirculating ammonia gas in towers. The ammonia brine was then gassed using carbon dioxide gas at moderate pressure in another type of tower. These two processes produce ammonium bicarbonate and sodium chloride, the double decomposition of which produces the desired sodium bicarbonate as well as ammonium chloride. The sodium bicarbonate is then heated until it decomposes into the desired sodium carbonate. The ammonia involved in the process is almost completely reduced by treatment with ammonium chloride and lime to produce ammonia and calcium chloride. The recovered ammonia is then reused in the processes described above.

The electrolytic production of caustic soda involves the electrolysis of a strong saline solution in an electrolytic cell. (Electrolysis is the breaking down of a compound in solution into its constituents using an electric current to produce a chemical change.) Electrolysis of sodium chloride produces chlorine, sodium hydroxide, or sodium metal. Sodium hydroxide in some cases competes with sodium carbonate in the same application processes. And in any case, both are interconvertible through fairly simple processes. Sodium chloride can be

converted into an alkali by one of two processes, the difference between them being only that the ammonia-soda reaction process produces chlorine in the form of calcium chloride, a compound of little economic importance, while electrolytic processes produce elemental chlorine, which has innumerable uses in the chemical industry industry.

Significant mineral reserves exist in several places in the worldform of soda ash, known as natural lye. Such deposits produce most of the world's natural alkali from vast deposits in underground mines.

Natural sodium metal.

Read the article Alkalis (source: Chemist's Encyclopedic Dictionary) and get a better idea of what alkali is, or watch a video about this chemical reagent.

Use of alkali in our environment

Alkali has found widespread use in our lives. Alkali can provide some form of water softening and remove impurities such as manganese, fluorides and organic tannins. Heavy industries use alkali in the form of lime to absorb and neutralize sulfur oxides in air emissions, thereby reducing the likelihood of acid precipitation. Sulfur dioxide produced by industrial plants and released into the atmosphere returns to the earth in the form of acid rain or sulfuric acid. Such areas exposed to acid rain are treated by aircraft with preparations that contain alkali. This makes it possible to control and neutralize the critical pH level of water and soil in areas where such man-made emissions occurred. Adding alkali to waste and wastewater, maintaining the correct pH level in oxidative processes during their decomposition. Stabilizes sediment formation in wastewater and reduces odor or formation of pathogenic bacteria. Sludge from wastewater bodies treated with quicklime complies with environmental standards, which makes it suitable for further use as fertilizer on agricultural lands.

Industrial applications of alkali

In industrial and mining operations, the use of alkalis in wastewater helps to neutralize harmful compounds and purify them. Treatment with excess alkali increases the pH of the water to 10.5-11 and can disinfect the water and remove heavy metals. Alkalis such as lime are key in the chemical production of calcium carbide, citric acid, petrochemicals and magnesia. In the paper industry, calcium carbonate is a causticizing agent for bleaching. The steel industry depends on lime as a component to remove impurities such as carbon monoxide gas, silicon, manganese and phosphorus.

Detergents formed by alkali

Alkaline detergents help in cleaning heavily soiled surfaces. These economical, water-soluble alkalis with a pH range of 9 to 12.5 can neutralize acids in a variety of types of dirt and deposits.

Alkali in glass and ceramics production

Alkali is the main raw material in glass production. Limestone, as well as sand, soda ash, lime and other chemicals, are fired at extremely high temperatures and turned into a molten mass. Glassblowers and potters use alkalis for glazes and fluxes, which react with acids to form silicates (glass) when heated. Concentrated alkalis create richer color in the glaze.

Literature about alkali

In the book by I. Nechaev "Stories about the Elements", published in 1940, in accessible and understandable language for the average person talks about what alkali is and how it differs from another caustic substance - acid. Excerpt from the text:

“Among the numerous substances that chemists have used in their laboratories since ancient times, caustic alkalis have always occupied a place of honor - caustic potassium and caustic soda. Hundreds of different chemical reactions are carried out in laboratories, factories and in everyday life with the participation of alkalis. With the help of caustic potassium and sodium can, for example, make most insoluble substances soluble, and the strongest acids and suffocating vapors can, thanks to alkalis, be deprived of all their pungency and toxicity.

Caustic alkalis are very peculiar substances. In appearance, these are whitish, rather hard stones, seemingly unremarkable in anything. But try taking caustic potassium or soda and holding it in your hand. You will feel a slight burning sensation, almost like touching nettles. Holding caustic alkalis in your hand for a long time would be unbearably painful: they can eat away the skin and meat to the bone. That is why they are called “caustic”, in contrast to other, less “evil” alkalis - the well-known soda and potash. By the way, caustic soda and potassium were almost always obtained from soda and potash.

Caustic alkalis have a strong attraction to water. Leave a piece of completely dry caustic potassium or soda in the air. After a short time, liquid will appear on its surface from nowhere, then it will all become wet and loose, and in the end it will spread out into a shapeless mass, like jelly. It is the alkali from the air that attracts water vapor and forms a thick solution with moisture. Whoever has to immerse his fingers in a solution of caustic alkali for the first time declares in surprise: “Like soap!” And this is absolutely correct. Lye is slippery, like soap. Moreover, soap feels “soapy” to the touch because it is made using alkalis. The solution is a caustic alkali and tastes like soap.

But a chemist recognizes caustic alkali not by its taste, but by how this substance behaves with litmus paint and acids. A piece of paper soaked in blue litmus dye instantly turns red when it is dipped into acid; and if you touch the alkali with this reddened piece of paper, it immediately turns blue again. Caustic alkali and acid cannot exist peacefully side by side for even a single second. They immediately enter into a violent reaction, hissing and heating up, and destroy each other until there is not a grain of alkali or a drop of acid left in the solution. Only then does calm come. The alkali and acid “neutralized” each other, they say in such cases. By combining them together, a “neutral” salt is obtained - neither sour nor caustic. So, for example, from the combination of hot hydrochloric acid with caustic soda, ordinary table salt is obtained."

Distinctive features of alkali.

From what we have read above, we already know that the opposite of alkali is acid. Instead of bitter taste inherent in alkalis, acids tend to have a sour taste. An example would be foods such as lemons or fruit vinegar (diluted), which are inherently acidic foods and contain acid in their composition. We can determine whether a substance is alkali or acid by knowing its pH. pH levels are measured using a pH scale; this scale ranges from 0-14, and these numbers tell us whether a substance is an alkali or an acid. Pure distilled water has a pH level of 7 and is called neutral (right in the middle of the scale). Any substance that has a pH above 7 is an alkaline substance, which may also be called an alkali. And, any other substance that has a pH below 7 is an acid.

Why is the substance alkaline?

So we already know that the pH level is a scale whose values range from 0-14 and indicate whether a substance is alkaline or acidic. However, we don't really know why. Let's look at this issue in more detail.

The pH level of a substance depends on how the atoms are arranged and combined in the substance. Pure water sits right in the middle of the scale and has a pH of 7. This means it contains equal amounts of hydrogen atoms (H+) and hydroxide atoms (OH-). When a substance has more hydrogen atoms (H+), it is an acid. When a substance has more hydroxide atoms (OH-), it is alkaline.

Where to buy lye?

You can buy alkali in Novosibirsk with a purity grade of analytical grade (pure for analysis) in the “For Business” store on the orders page: or. For non-resident buyers, goods can be sent by Russian Post or transport companies.

Alkalis are caustic, solid and easily soluble bases. Acids are generally acidic liquids.

Definition

Acids– complex substances containing hydrogen atoms and acidic residues.

Alkalis– complex substances containing hydroxyl groups and alkali metals.

Comparison

Alkalis and acids are antipodes. Acids create an acidic environment, and alkalis create an alkaline environment. They enter into a neutralization reaction, as a result of which water is formed, and the pH environment is converted from acidic and alkaline to neutral.

Acids have a sour taste, while alkalis have a soapy taste. Acids, when dissolved in water, form hydrogen ions, which determine their properties. All acids exhibit similar behavior when entering into chemical reactions.

When dissolved, alkalis form hydroxide ions, which give them their characteristic properties. Alkalis attract hydrogen ions from acids. Alkalies have characteristic features that appear during chemical reactions.

The strength of alkalis and acids is determined by pH. Solutions with a pH less than 7 are acids, and solutions with a pH greater than 7 are alkalis. Alkalies and acids are distinguished using indicators - substances that change color when in contact with them. For example, litmus turns blue in alkalis and red in acids.

To make the experiment more reliable, another indicator is added to the alkalis - colorless phenolphthalein. It colors alkalis in a characteristic crimson color, and remains unchanged with acids. Traditionally, alkalis are determined using phenolphthalein.

At home, acid and alkali are recognized using simple experiment. Add liquid to baking soda and observe the reaction. If the reaction is accompanied by the rapid release of gas bubbles, it means that there is acid in the bottle. Alkali and soda, which by its nature are the same as alkali, do not react.

Conclusions website

Acids and alkalis are unable to coexist peacefully even for one second when in contact. Having mixed, they instantly begin a stormy interaction. The chemical reaction with them is accompanied by hissing and heating and lasts until these ardent antagonists destroy each other.
Acids tend to form an acidic environment, and alkalis tend to form an alkaline environment.
Chemists distinguish an alkali from an acid by its behavior with litmus paper or phenolphthalein.

Alkalis are water-soluble strong bases. Currently, the Brønsted-Lowry and Lewis theory is accepted in chemistry, which determines acids and bases. According to this theory, acids are substances capable of removing a proton, and bases are capable of donating an electron pair OH−. We can say that bases mean compounds that, when dissociated in water, form only anions of the OH − type. To put it simply, alkalis are compounds consisting of a metal and the hydroxide ion OH − .

Alkalies usually include hydroxides of alkali and alkaline earth metals.

All alkalis are bases, but not vice versa; the definitions “base” and “alkali” cannot be considered synonymous.

The correct chemical name for alkalis is hydroxide (hydroxide), for example, sodium hydroxide, potassium hydroxide. Names that have developed historically are also often used. Due to the fact that alkalis destroy materials of organic origin - leather, fabrics, paper, wood, they are called caustic: for example, caustic soda, caustic barium. However, chemists use the term “caustic alkalis” to define hydroxides of alkali metals - lithium, sodium, potassium, rubidium, cesium.

Properties of alkalis

Alkalis are white solids; hygroscopic, water soluble. Dissolution in water is accompanied by active release of heat. They react with acids to form salt and water. This neutralization reaction is the most important of all the properties of alkalis. In addition, hydroxides react with acidic oxides (forming oxygen-containing acids), with transition metals and their oxides, and with salt solutions.

Alkali metal hydroxides are soluble in methyl and ethyl alcohols and can withstand temperatures up to +1000 °C (with the exception of lithium hydroxide).

Alkalis are active chemical reagents that absorb from the air not only water vapor, but also molecules of carbon dioxide and sulfur dioxide, hydrogen sulfide, and nitrogen dioxide. Therefore, hydroxides should be stored in a sealed container or, for example, air access to a vessel with alkali should be organized through a calcium chloride tube. Otherwise, the chemical reagent after storage in air will be contaminated with carbonates, sulfates, sulfides, nitrates and nitrites.

If we compare alkalis by chemical activity, it increases as we move along the column of the periodic table from top to bottom.

Concentrated alkalis destroy glass, and molten alkalis even destroy porcelain and platinum, so it is not recommended to store alkali solutions in vessels with ground glass stoppers and taps, as the plugs and taps may jam. Alkalies are usually stored in plastic containers.

It is alkalis, not acids, that cause more severe burns, since they are more difficult to wash off the skin and penetrate deep into the tissue. The alkali should be washed off with a non-concentrated solution of acetic acid. It is necessary to work with them wearing protective equipment. An alkaline burn requires immediate medical attention!

Application of alkalis

- As electrolytes.
— For the production of fertilizers.
— In medicine, chemical, cosmetic production.
— In fish farming for sterilization of ponds.

In the Prime Chemicals Group store you will find the most popular alkalis at competitive prices.

Sodium hydroxide

The most popular and in demand alkali in the world.

It is used for saponification of fats in the production of cosmetics and detergents, for the production of oils during oil refining, as a catalyst and reagent in chemical reactions; in the food industry.

Caustic potassium

It is used for the production of soap, potash fertilizers, electrolytes for batteries and accumulators, and synthetic rubber. Also - as a food additive; for professional cleaning of stainless steel products.

Aluminum hydroxide

Demanded in medicine as an excellent adsorbent, antacid, enveloping agent; vaccine ingredient in pharmaceuticals. In addition, the substance is used in wastewater treatment plants and in processes for producing pure aluminum.

Calcium hydroxide

A popular alkali with a very wide range of applications, which is known in everyday life as “slaked lime”. Used for disinfection, water softening, in the production of fertilizers, caustic soda, bleach, and building materials. Used to protect trees and wooden structures from pests and fire; in the food industry as a food additive and reagent in the production of sugar.