Alkalis are caustic, solid and easily soluble bases. Acids are generally acidic liquids.
What are acid and alkali
Acids– complex substances containing hydrogen atoms and acidic residues.
Alkalis– complex substances containing hydroxyl groups and alkali metals.
Comparison of acid and alkali
What is the difference between an acid and an alkali? 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.
TheDifference.ru determined that the difference between acid and alkali is as follows:
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.
The acid-base table of foods will help you in creating the optimal diet. The acid-base balance should consist of 70-80% alkaline foods and 20-30% acid-forming foods. There are good and bad acid-forming foods out there, it's important to know the difference. Because bad acids should be avoided consistently. It is not always easy to correctly correlate the basic and acid-forming properties of food products in everyday life.
Content:
Acid-base balance
The blood needs the right balance of acidic and basic (alkaline) compounds to function properly. This is called acid-base balance. Your kidneys and lungs work to maintain acid-base balance. Even small deviations from the normal range can have a significant impact on your vital organs.
Acid and alkaline levels are measured on the pH scale. An increase in acidity causes the pH level to drop. An increase in alkalinity causes an increase in pH levels.
When the level of acid in the blood is too high, it is called acidosis. When your blood is too alkaline, it is called alkalosis.
And alkalosis is caused by a problem with the lungs. Metabolic acidosis and alkalosis are caused by a kidney problem.
Each of these acid-base imbalances is caused by an underlying disease or disorder. Treatment depends on the cause.
How to check the acid-base balance of the body
It is not easy to tell what the acid-base balance is at any given time. The only real external signs there may be are weak bones, receding gums, weak or broken teeth and muscle loss, and even these signs are not necessarily indicative.
This is why checking your acid-base balance is so important for your health. Testing your body's pH will give you an idea of whether your body is tending toward metabolic acidity or being in the balanced, slightly alkaline state that it needs. This test is relatively simple and can be done in your own home.
Acid-base balance of urine
It is better to test the second urine of the day. Your first urine will be overly acidic as it dumps waste from the night before. When you are ready, simply tear off a small piece of litmus paper and place it in the urine stream for a few seconds. Or, you can pee in a small cup and dip the paper in your urine that way.
Look at the color of your paper and compare it to the color chart on the litmus paper. You want to target a urine pH level of 6.0-6.5. Although many alkalizing diets and websites will claim that 7.0-7.5 is needed, I don't think this is ideal based on science and my research. If you check later in the day and your urine is more like 6.5-7.0, this is normal as we become more alkaline during the day.
Acid-base balance measurement First, our kidneys need to eliminate acids, so we want our urine to do acid work. If the urine is too alkaline, it could mean that the kidneys are not working properly or there is something going on in the metabolic state. Keep in mind that some supplements, such as vitamin D, calcium, and magnesium, may throw off your pH balance a little in some cases. If you want to know your "true" pH, go a few days without supplements and then test again.
Acid-base balance of saliva
This measures your body's enzyme stores and the function of digestive organs such as the stomach, pancreas and liver. You need to check first in the morning before brushing your teeth or even drinking water. The ideal range is 6.5-7.0. This shows that you have a good supply of minerals, but it also shows that you are digesting your food well. If it's more than 7.0, your digestive system may be a little sluggish and you may have problems with gas, constipation and fungus/mold.
Our acid-base chart lists virtually all alkaline and all acid-forming foods.
You may be wondering why we keep talking about the alkaline diet and not the basal diet. This is simply because we do not recommend an alkaline diet as a permanent diet:
A purely basal diet is excellent for detoxification and also accompanies a colon cleanse. Thus, the main diet is more for short-term actions.
-Basic nutrition consists not only of alkaline foods, but also acidic foods. After all, not all acid-forming foods are bad and unhealthy.
What does alkaline mean?
Don't think that the designation is alkaline, it's like alkaline soap.
Rather, it is about how food acts in the body and what substances are produced when it is metabolized in the body.
Please note that there are currently many different acid-base tables on the Internet or in the literature - and they are all different more or less from each other.
Alkaline Fruit Chart
Apples Mango
A pineapple
Apricots Nectarines
Avocado Olives (green, black) Grapefruit
Bananas Oranges
Clementine Papaya
fresh dates Peaches
Strawberry Prunes
Figs Lingonberries
Grapefruit Quince
Blueberries Currants (red, white, black)
Raspberry Gooseberry
Melons Dried Fruits
Cherries (sour, sweet;) Watermelons
Kiwi Grapes (white, red)
Limes Lemons
Tangerines Prunes
Alkaline Vegetables Chart
Algae (Nori, Wakame, Hijiki, Chlorella, Spirulina) Okra
Artichokes Pepper
Eggplant Parsnips
Whitening Celery Parsley Root
Cauliflower Radish
Green beans Radishes (white, black)
Broccoli Romanesco (Flowers)
Chicory Brussels sprouts
Chinese cabbage Beetroot
Peas, fresh cabbage leaf
Fennel Shallot
Green onion Black root
Cabbage Asparagus
Cucumbers Cabbage Spitz (Sugar Loaf)
Carrot
Potato Tomato (raw)
Garlic White cabbage
Kohlrabi Savoy
Pumpkin types Zucchini
Leek (Leek) Onion
Chard Celery
(white turnips)
Tables of alkaline mushrooms
Oyster mushrooms Shiitake
Champignons White mushrooms
Rings Truffles
Chanterelles...and many others
Table of Alkaline Herbs and Alkaline Salads
Basil
Batavia salad Lollo-Salads (Biondo/Rosso)
Savory Marjoram
Borage Horseradish
Spanish Salad
Cress Melissa
Chinese cabbage Nutmeg
Chicory Carnations
Pepper Oregano
Dill Parsley
Watercress salad Pepper (all types)
Iceberg lettuce
Chicory Allspice
Field salad Rosemary
Fennel seeds Arugula (Arugula)
Friseesalat Saffron
Garden Cress
Ginger Sorrel
Capers Green onions
Cardamom Black Cumin
Chervil celery leaves
Coriander Thyme
Salad Vanilla
Cress Wild Herbs
Cumin Hyssop
Cumin Cinnamon
Melissa
Pan di Azucar Bitter winter salad
Lovage...and many others
Alkaline Sprouts Table
Alfalfa-Sprouts Radishes-Cabbage
Fenugreek Sprouts Radish Sprouts
Brown Millet Sprouts Rye Shoots
Broccoli-Cabbage Cabbage-Cabbage
Spelled sprouts Arugula Sprouts
Barley sprouts Mustard sprouts
Millet-Sprouts Seeds-Sprouts
Flax Seeds Wheat Sprouts Shoots
Lentil Sprouts...and many others
Table of Alkaline Nuts and Seeds
Forest Almond
Walnut Maroni (Chestnuts)
Alkaline protein
Lupine Protein Tablets Lupine flour
Alkaline Drinks
Fruit smoothie
Green Smoothie
Herbal teas
Protein shake with Lupine protein
Water
Water with 1 tsp. apple cider vinegar
Lemon water (200 ml water with the juice of half a lemon)
Acid-Forming Products
Sour or acid-forming foods should be combined with main foods as much as possible.
Acid-forming foods are not automatically bad or unhealthy in any way. On the contrary, there are foods that can act acid-forming, but at the same time are very healthy, such as nuts or legumes.
Unlike the bad ones, they only act on a few levels of acidification.
The so-called good acidic foods should definitely be included in the nutritional base, while you abstain from the bad ones.
Good acid-forming foods
- Organic grains (such as spelt, Kamut or barley in small quantities - much like wheat germ or sprouts)
- Grain products such as bulgur and couscous, but from spelt, from wheat
- Oats/oat flakes (BIO-quality)
- Millet rice and whole grains (brown rice)
- Legumes (e.g. bean kernels, lentils, chickpeas, peas, etc.)
- High quality cocoa powder, as well as homemade chocolate
- Corn (eg polenta, corn pasta)
- Nuts (such as walnuts, hazelnuts, macadamia nuts, Brazil nuts, frosted coconut flakes (also coconut), etc.)
- Oilseeds (e.g. sesame, hemp seed, sunflower seeds, pumpkin seeds, poppy seeds, chia seeds, etc.; the seeds are sprouted, they become more alkaline depending on the sprout)
- Plant-based protein powders (if protein deficient), such as hemp protein, rice protein, and pea protein
- Pseudo-grains (eg quinoa, amaranth, buckwheat)
- Animal products from organic agriculture in moderation (such as organic eggs or fish from organic aquaculture)
- Tofu (organic only) and quality fermented organic soy products such as miso and tempeh
Good acid-forming drinks
- Green tea (properly prepared - at low temperatures and short brewing)
- Lupine coffee
- Drinking chocolate (homemade, such as almond milk and raw cocoa powder)
- High-quality plant drinks: rice drink, oat drink, soy drink – respectively without Süssungsmittel, flavourings, thickeners, etc.
Bad acid-forming foods (animals)
- Eggs from traditional farming
- Fish and seafood from conventional aquaculture or from contaminated regions
- Meat from traditional agriculture
- Meat Broth, Sausages, Ham
- Dairy products (for example, cottage cheese, yogurt, kefir, whey and all cheeses, also sheep and goat; and low-fat dairy products)
Exception: butter, ghee and cream (bio-quality), which can be classified neutrally
Bad acid-forming foods (plant-based)
- Vinegar (wine vinegar, exception: unclarified apple cider vinegar)
- Finished products of all types
- Cereal products made from flour (Bread and pasta products, such as bread, rolls, pretzels, cakes, cookies, sweet particles, pasta, etc., some breakfast products, such as corn flakes, ready-made corn flakes, crunchies, etc. )
- Gluten containing products (for example, seitan products such as vegetarian sausages, bolognese, etc.)
- Ketchup (exception: homemade, such as tomato and date ketchup)
- Sour canned food
- Mustard (exception: high quality organic mustard)
- Soy products (if highly processed, particularly textured soy proteins
- Ice cream (water, soy and frozen yogurt - exception: Alkaline ice)
- Sugar (all products that contain sugar) – coconut sugar.
Bad Acid Forming Drinks
Alcohol and caffeinated drinks
Carbonated drinks (such as lemonade, cola, etc.), soft drinks such as juice from concentrate, protein drinks, sweetened milkshakes, weight loss drinks.
Coffee, beans, instant and decaffeinated coffee
Milk
Mineral water and generally carbonated drinks
Tea (black tea, fruit tea, iced tea, etc., only herbal tea is alkaline)
Don't forget to drink clean water!
Before distinguishing acids from alkalis, you need to understand the concepts of acid, alkali and base, after which we will move on to the so-called indicators, with the help of which you can easily distinguish between these substances.
What is an acid?
Acid is a chemical compound. Typically, solutions of acids (those that can be tasted) taste sour; examples include acetic, malic, ascorbic and citric acids. The acid contains hydrogen and oxygen, as well as additional elements (or a complex of elements), which usually give the acid its name - nitric, sulfuric, carbonic, ethyl-sulfuric, etc.
Acid is a complex substance whose molecule contains one or more hydrogen atoms and an acid residue.
Features of acids
The characteristic chemical properties of the acid are:
- sour taste
- the ability to convert blue plant matter—litmus—to red
- the presence in an acid molecule of one or more hydrogen atoms that can be exchanged for the metal to form a salt.
The properties of acids are determined by the fact that they are able to replace hydrogen atoms in their molecules with metal atoms. For example:
Basic properties of acids
Effect of acid solutions on indicators. Almost all acids (except silicic acid) are highly soluble in water. Solutions of acids in water change the color of special substances - indicators. It is by the color of the indicators that the presence of acid is determined. The litmus indicator is colored red by acid solutions, and the methyl orange indicator is also red.
Interaction of acids with bases. This reaction is called a neutralization reaction. An acid reacts with a base to form a salt, in which the acidic residue is always found unchanged. The second product of the neutralization reaction is necessarily water.
Interaction of acids with basic oxides. Since basic oxides are the closest relatives of bases, acids also enter into neutralization reactions with them. As in the case of reactions with bases, acids form salt and water with basic oxides. The salt contains the acid residue of the acid that was used in the neutralization reaction. In reaction with basic oxides, acids form salt and water. The salt contains the acid residue of the acid that was used in the neutralization reaction.
For example, phosphoric acid is used to clean iron from rust (iron oxides). Phosphoric acid, removing its oxide from the surface of the metal, reacts very slowly with the iron itself. Iron oxide turns into a soluble salt, FePO4, which is washed off with water along with acid residues.
Interaction of acids with metals. The metal must be sufficiently active (reactive) with respect to acids. For example, gold, silver, copper, mercury and some other metals do not react with acids to release hydrogen. Metals such as sodium, calcium, zinc, on the contrary, react very actively, releasing hydrogen gas and a large amount of heat.
What is lye?
Alkalis are called strong bases that are soluble in water. If a substance contains hydroxy groups (OH) that can be broken off (like a single "atom") in reactions with other substances, then the substance is a base.
Reasons are substances in which metal atoms are bonded to hydroxy groups. That is, alkali is a substance consisting of a metal and an OH group (hydroxy group). The alkali neutralizes the cyst to produce water and salt.
Physical properties: solutions of alkalis in water are soapy to the touch, they corrode skin, fabrics, paper - caustic alkalis(caustic soda NaOH, caustic potassium KOH). On the skin they cause long-lasting wounds. Very hygroscopic.
How to distinguish an acid from an alkali?
You can distinguish an acid from an alkali using indicators. Now there are quite a lot of indicators - substances that help determine the composition of the environment. The indicators change color depending on the composition of the medium. This happens because in acidic and alkaline environments, indicator molecules have different structures.
For example indicator phenolphthalein in an acidic environment it is in the form of undissociated molecules, and the solution is colorless, and in an alkaline environment, it is in the form of singly charged anions, and the solution has a crimson color. Litmus turns red in an acidic environment, and blue in an alkaline environment.
Tea this is also an indicator. Probably many have noticed that if you put lemon in strong black tea and even drop a few drops (add acid), the tea will lighten. And if you dissolve baking soda (lye) in it, it will darken.
The color of the indicator will change in acid and alkali solutions
It’s not for nothing that there is a common expression “litmus test”. For the litmus indicator, they even came up with mnemonics with which you can remember the connection between the color of the indicator and the substance being determined:
- Red litmus indicator - acid will indicate clearly
- Blue litmus indicator. The alkali is here - don’t be so open!
Of the inorganic medicinal substances, acids, alkalis, and salts of alkali and alkaline earth metals are of greatest importance for the body. These compounds are electrolytes, i.e. in solutions dissociate into ions.
Acids
(diluted hydrochloric acid and 0.1 N solution, boric acid, salicylic acid, etc.)
The biological action of acids depends mainly on hydrogen ions; therefore, their activity is determined by the degree of dissociation. During the dissociation of most acids, the anion does not play a significant role in the action of the acid. An exception is hydrocyanic acid (HC), the toxic properties of which depend on the C anion.
Local action.
Acids, interacting with the whites of the skin and mucous membranes, form dense, water-insoluble albuminates that do not penetrate deep into the tissue.
In low concentrations, the acid has an astringent effect (anti-inflammatory), and in higher concentrations it has an irritating and cauterizing effect. The astringent effect is more pronounced with weak acids; cauterizing - for the strong. For example, boric and salicylic acids dissociate weakly, they have an anti-inflammatory effect, antibacterial, antifungal effect, are used as antiseptics, depending on the concentration, salicylic acid has keratoplastic (stimulates epithelization) 1-2%, or keratolytic (peeling) 10-20% action.
The local action of acids is accompanied by reflex reactions, their magnitude and nature depend on the intensity of the action of the acid.
Strong inorganic acids (sulfuric, hydrochloric, nitric) cause coagulative necrosis; they take away water and form a dense albuminate on the surface of the tissue - a dry scab.
Of particular interest is the effect of acids on the secretion and motility of the gastrointestinal tract. This action was studied by the school of I.P. Pavlov. Acids are necessary for digestion (for example, diluted hydrochloric acid), they promote the action of pepsin, increase the secretion of gastric and pancreatic juices, delay the transfer of stomach contents to the duodenum, since when they enter it they cause contraction of the pyloric part of the stomach, which only relaxes after neutralizing the incoming acid.
Resorptive action.
After absorption into the blood or parenteral administration, acids are immediately neutralized by buffer systems and do not have a resorptive effect.
When a large amount of acid enters the blood, alkaline reserves are depleted and first compensated, then uncompensated acidosis develops (pH<7,35).
Thus, the clinical picture of acid poisoning consists of the symptoms of their local action and the phenomena of uncompensated acidosis (coma, depressed breathing, drop in blood pressure).
Help measures: Remove acid from the surface of the skin with water or a weak solution of alkali (soda-bicarbonate Na). If the acid is taken internally, it is neutralized with a weak alkali - magnesium oxide. To prevent shock, narcotic analgesics (promedol, omnopon) and antispasmodics (atropine, no-spa) are administered. Means of specific therapy for acidosis (Na bicarbonate, trisamine), carry out symptomatic and dosintoxication therapy.
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.