When we hear about biotechnology, images of sparkling reactors from of stainless steel, specialists in snow-white coats, pipettes, syringes and computer-controlled processes taking place in immaculately clean laboratories. It is unlikely that we think about shovels, rusty boilers the size of a man, urine and manure. Nevertheless, it was with these tools that saltpeter workers worked with their “reagents” - perhaps the first chemists in general and biotechnologists, in particular, whose wages came from the corresponding royal or republican treasury - that is, from state budget.

Saltpeter at work - 17th century engraving

Perhaps modern chemists may be dismayed by this comparison, but it was with saltpeter that the state-sponsored chemical industry began. Despised by employers and the nobility, but, nevertheless, well-organized gangs of saltpeter were the horror of the farms of the 16th-17th centuries - with the permission of the crown, they ransacked barns, stables, and sometimes latrines, collecting a wonderful substance that gave the name to their profession - saltpeter or potassium nitrate KNO 3 .

(In Russian, the word "saltpeter", in all likelihood, comes from the Latin sal nitrum- nitrogen salt; the English etymology of the same word - "saltpeter" is easier to trace - it comes from Greek words sal- salt and petre- a rock).

The appearance and increasing importance of firearms led to the dependence of the combat effectiveness of armies on imported raw materials, which could not but disturb the kings and parliaments of such countries as, for example, France, England and Sweden, and therefore the strategy of import substitution of saltpeter with its local sources soon became one of the priorities military-economic policy of European states.

Potassium nitrate is also used in the food industry. Potassium nitrate is known as food additive E252, used to preserve meat, for example in raw smoked sausages, while the practice of using saltpeter to extend the shelf life of meat products is very ancient - it goes back to the Middle Ages. However, at present, preservatives based on potassium nitrate are being replaced by preservatives such as sodium nitrate and nitrite.

There is a strong legend in the armies of Britain and the United States that potassium nitrate is an antiaphrodisiac, and it is added to the food of military personnel to suppress their sexual activity, but there is no scientific basis for this legend. She went, most likely, from those times when, before long-distance sailing trips in the Navy of His (well, or Her) Majesty, corned beef was preserved again with the help of saltpeter. If you read novels and stories about the harsh everyday life of the sailors of the sailing fleet (say, the cycle about the path of Horatio Hornblower from midshipman to admiral), it becomes clear that the work that the sailors of the sailing fleet did was the most guaranteed anti-aphrodisiac.

Such is our today's wonderful substance - Indian saltpeter or simply saltpeter. I will only add that the history of its mining and industrial production of saltpeter refutes the well-known maxim, known as the third law of experimental chemistry: “If you add a spoonful of shit to a barrel of jam, you get a barrel of shit”. True, in fairness, this law is more often applied to organic chemistry and organic syntheses, and potassium nitrate, despite the possibility of obtaining using biotechnology, is still an inorganic substance.

Well, I remind you that this address is the vote of the readers of the competition of scientific blogs -2013 from SRTF, for which this cycle about the life of wonderful substances is nominated, and therefore, if you, the readers, want to express gratitude (or loud fu) to the biographer of these wonderful substances, you you can go there and vote.

This entry was originally posted at

Introduction

You wanted to conduct your own chemical experiment. Not a bad desire, but for this you need to have a specific goal, and most importantly - the ingredients. So you sit down at the computer and look for interesting recipes. Oh, it seems that they found what they need - "Making a smoke bomb." We read the list of ingredients: "Sugar, soda, so-and-so ... Potassium nitrate? What kind of animal is this?" - the standard train of thought for those who read this recipe. Usually in this way they learn about the existence of potassium nitrate. Naturally, immediately there is a desire to find more information about it. Today I will try to satisfy your interest.

origin of name

First, let's talk about its name. Saltpeter is any salt that has an acidic NO3 residue taken from nitric acid, i.e. is a nitrate. The chemical formula of the saltpeter being discussed now is KNO3, which means that the adjective "potassium" must be added to its name. But there are other spellings as well. In various sources, it can be called potassium / Indian nitrate, potassium nitrate, potassium nitrate, etc. All of these names will be correct.

Properties

This saltpeter under normal conditions is colorless crystals, but crushed it resembles a white powder. It also has an ionic structure and a hexagonal or rhombic crystal lattice. Potassium nitrate is slightly hygroscopic, tending to caking slightly over time. It is also non-volatile and odorless. It dissolves well in water, to an average degree - in liquid ammonia, glycerin, hydrazine, does not dissolve in pure ether and ethanol (it can dissolve poorly in them only if the latter are diluted with water). Acicular and very long crystals can grow from potassium nitrate during its slow crystallization. At a temperature of 400-520 ° C, it decomposes, at which potassium nitrite and oxygen are formed.

It is also a strong oxidizing agent that reacts with reducing agents and combustible materials, and if it is crushed in addition, the reaction is very active and often accompanied by an explosion (photo). Potassium nitrate can independently ignite some organic materials if they are mixed with it. A melt of potassium nitrate can be used to obtain potassium through electrolysis, but, as she has high oxidizing abilities in this state, for this experiment it is better to take potassium hydroxide.

Receipt

In the Middle Ages and the New Age (that is, in the period when gunpowder was in frequent use), potassium nitrate was mined from saltpeter - heaps consisting of limestone materials, manure and other rotting components, which had layers of brushwood or straw. They were covered with turf to contain the resulting gases. Ammonia, which was formed due to rotting manure, accumulated in the layers, nitrified and became first nitrous, and then nitric acid. The latter, when interacting with limestone, formed calcium nitrate, then it was leached with water. When wood ash was added to this mixture, the calcium carbonate in the first one settled. And the result was a solution of potassium nitrate. The interaction of potash and calcium nitrate is the oldest way to obtain potassium nitrate, which is still popular. Although potash can be replaced with potassium sulfate. Potassium nitrate can be obtained in the laboratory with the following reactions:

• Potassium chloride and sodium nitrate.
• Ammonium nitrate and potassium chloride.
• Potassium hydroxide and nitric acid.
• Potassium and nitric acid.
• The corresponding alkaline potassium oxide (K2O) and the corresponding acid (nitric).
• Potassium hydroxide and nitric oxide (5).
• Ammonium nitrate and potassium hydroxide.
• Potassium carbonate and nitric acid.

Being in nature

In nature, potassium nitrate is known as the mineral nitrokalite. The places of its largest deposits are Chile and the East Indies (which is why potassium nitrate is often called Indian). Natural potassium nitrate is azotobacteria associated with ammonia, which is released during the decomposition of nitrogenous substances. Moisture and heat contribute to this connection, therefore the largest deposits of potassium nitrate are located in hot countries. It is also present in very small amounts in animals and plants.

Potassium nitrate: application

It is mainly used as a valuable fertilizer for plants (photo). It is also a very important ingredient in the composition of black powder ("smoke guns", smoke bombs). This saltpeter is also useful in optical glassmaking, discoloring and brightening technical crystal glasses and giving strength to glass products. In the food industry, this saltpeter is known as preservative E252.

Conclusion

Potassium nitrate (formula KNO3) can be used not only in chemistry, but also in many other industries. It can be both useful and very harmful to a person.

Potassium nitrate or KNO3 is very often used in the field of pyrotechnics and as a potassium - nitrogen fertilizer. Potassium nitrate is used as a fertilizer for various crops. Of course, you can buy it in specialized stores, but it will be easier and better for you to make it yourself. It is easy to recognize potassium nitrate - these are most often colorless or white crystals of an oblong shape and odorless. Potassium nitrate, according to its physical properties, dissolves well in water. So let's try to make them ourselves.

How to make potassium nitrate with your own hands?

To create, we will use the following materials:

NH4NO3 - Ammonium nitrate.
. KCl - Potassium chloride.

1. The first step is to take ammonium nitrate and potassium chloride in a 1:1 ratio. Separately, we dilute ammonium nitrate with water in a ratio of 1: 3, and dilute potassium chloride in a separate vessel in proportions of 1: 2. Do not forget and be sure to mix everything separately!

2. Two solutions must be mixed and boiled over low heat. Attention: ammonium nitrate begins to release ammonia during the reaction, so ventilate the room well to avoid unpleasant odors and possible headache and nausea.

3. After the ammonia smoke ceases to stand out, put the solution in the refrigerator until long white crystalline needles form in the sediment. After cooling, the crystals should be thoroughly rinsed and allowed to dry. That's all, potassium nitrate is ready!

There is nothing difficult in creating saltpeter, you just need to follow the safety rules and repeat the chemistry.

VIDEO. How to make potassium nitrate at home?

AT recent times you will not find potassium nitrate "in the afternoon with fire" in any garden store. About fire, by the way, this is not a metaphor, since this substance is not only fertilizer, but also one of the components for the manufacture of pyrotechnics. Let's not despair, because you can cook potassium nitrate at home. This method is very simple, and even if you are not a third-generation chemist, you will be able to figure out how to make potassium nitrate.

Preparation for work

• First of all, you need to buy some reagents, namely: ammonium nitrate (ammonium nitrate) and potassium chloride. These substances are fertilizers, so they can be found in the garden store and are quite affordable.
• Potassium chloride is produced in two types, which differ in color and price: red - unrefined, white - purified. Naturally, the purified composition will be somewhat more expensive, but the unpurified one is also suitable for our business.
• It is even easier with ammonium nitrate, it is produced in the form of whitish granules with a slight yellowness. It differs only in the mass of the packaged package: from 1 to 5 kg. Accordingly, the larger the package, the cheaper the cost of fertilizer.

When everything you need is purchased, you can proceed to the main part: the recipe for how to make potassium nitrate.

Recipe for potassium nitrate

1. Measure out 100 g of potassium chloride (crude) and add hot water 300-350 g. Use distilled water whenever possible, as you will get a cleaner product. For a more convenient mixing process, use a half-liter glass or plastic bottle. Shake the bottle vigorously to dissolve the chloride completely.
2. Next, the solution should be filtered through a cotton cloth. Moisten it with warm water beforehand, so the process will go faster. The filtered liquid should be clear or light pink in color.
3. Pour this solution into an enamel pan and heat until the first signs of boiling, then pour 95 g of ammonium nitrate in small portions, remembering to constantly stir the solution.
4. Boil the liquid on a high heat, about 3 minutes, stirring again.
5. After the appointed time, remove the pan from the heat and leave it for a few minutes until the liquid stops steaming.
6. Pour the solution into a plastic container and place in a cool place until it cools completely. This process will take about 2-3 hours. plastic utensils good in that it is a poor conductor of heat, which means that the solution will cool gradually. As a result, you will receive a quality product field
7. When the substance has completely cooled, it should be put in the refrigerator for an hour.
8. Next, move the container to the freezer for 3 hours.
9. We waited due time? The crucial moment has come, pull the solution out of the freezer and carefully drain the water. Elongated crystals of potassium nitrate should remain at the bottom.
10. Put potassium nitrate on a newspaper and leave to dry in a warm place for 3-4 days.

And finally, if all the work is carried out according to the recipe, how to make potassium nitrate, you are guaranteed an excellent result.

If you need it, then watch the video - how to cook potassium nitrate at home

Most workers in the agricultural and gardening sector are well aware of such a concept as potassium nitrate. This is a compound of a chemical nature, which is a fertilizer with two components at its core. Its manufacture is carried out in full compliance with GOST. Potassium nitrate should be used for different types soils. But especially for those where there is a high sensitivity to chlorine.

The composition of ammonium-potassium nitrate includes two main components - nitrogen and potassium. The content of the latter is almost 50%. To date, this complex fertilizer widely used for feeding various crops. Appearance potassium nitrate is quite characteristic - these are white granules with a slightly yellowish tint. Sometimes available as a white powder.

It has acquired particular value for plants in connection with the following properties:

Thanks to this number useful properties, as a fertilizer, potassium nitrate is in great demand. It is used for soils of different composition. These can be soils with various vineyards, beds with flax, carrots, beets, raspberries, grapes and tobacco. But especially it has proven itself when used in soils sensitive to chlorine.

Correct Application

The simple purchase of fertilizer does not necessarily guarantee that there will be a rich harvest later. For the best result, you need to follow certain rules for the use of fertilizer. Ammonium-potassium nitrate in the form of a dry mixture should be diluted with water in the correct ratio and carry out a complete top dressing.

You can perform it in the root or non-root way.

In the first case, for 10 liters of water, depending on the type of plants, dry fertilizer will be required in the following quantities:

• flowers and vegetable crops- 30g;
• fruit trees - 40 g;
• ornamental plantings and berry bushes - 30g.

The multiplicity of such dressings can be once every couple of weeks.

Foliar top dressing is carried out no more than four times during the growing season and consists in a simple spraying of plants. Potassium nitrate is mainly used in a 2% solution. At the same time, for one square meter for vegetables and flowers, 1 liter of such a solution is required, for bushes with berries 1.5 liters, and for fruit trees- from 1.5 to 8 liters, depending on their age.

The first application of fertilizer should be carried out in April, the next in May, when seeds will be sown in the soil. It is also useful to fertilize fruit trees in the autumn months. This will allow them to endure the approaching cold. But it is important not to overdo it with fertilizer, since its excess is fraught with a deterioration in the condition of crops and a reduction in yield.

home cooking

Many experienced gardeners have long adapted to cook ammonium-potassium nitrate right at home. And beginners often wonder how to make potassium nitrate under conditions home furnishings. In fact, the cooking process is quite fast and understandable. First you need to stock up on potassium chloride, ammonium nitrate, distilled water and absolutely clean and dry dishes.

And then follow the following instructions:

• potassium chloride weighing 100 g diluted in distilled hot water(300 g), using a glass container for this purpose (best of all, a regular bottle);
• carefully filter the resulting solution through several layers of gauze until an almost transparent solution is obtained;
• heat the solution in an enameled container until the first bubbles form, then pour 95 g of ammonium nitrate into it and mix;
• leave the solution to boil for three minutes, stirring occasionally; then remove from the heat, place in another container and leave to cool in a cool place;
• after three hours, send the container with the solution for one hour inside the refrigerator;
• move the solution to freezer for three hours (at 0°C);
• remove the container from the refrigerator and carefully drain upper layer liquids;
• dry the resulting precipitate for three or four days on paper.

It is this precipitate that is ammonium-potassium nitrate. If you follow all the above steps strictly according to the instructions, you can get up to 60 g of dry matter at the exit. From all of the above, it becomes clear that self-fertilization is not very difficult. Therefore, the question of how to make potassium nitrate correctly should not subsequently arise.

Security measures

Not everyone knows, but potassium nitrate is widely used in pyrotechnics, since it actively reacts with various combustible substances and reducing agents. Therefore, it should be stored in compliance with all safety measures: in sealed packaging, away from flammable and combustible substances.

Fertilizer should not be kept near any heating devices, even near a working light bulb. Protective equipment in the form of rubber gloves should always be used when preparing solutions. The airways must be closed with a respirator. And most the best option will use all the powder immediately after purchase.

Potassium nitrate, the use of which was carried out correctly, will have an amazing effect on the properties of the soil, which in turn will have a beneficial effect on vegetable, fruit crops and plants. This will allow you to get a decent harvest and protect plants from the effects of adverse conditions.