By the way, almost every store that sells household items has a department of chemical goods. It's scary to think how our distant ancestors, who did not know either soap or washing powders, washed their dirty clothes in river water...

No, I'm not going to teach you how to wash properly. But since washing and many other things are directly related to chemical miracles, let's set up experiments that will help you understand what happens in this case. And maybe, having gained new knowledge, you will do something better and faster. Put a small piece of laundry soap in a bottle of warm water, close the bottle with your finger and shake it well. Add a few drops of phenolphthalein solution to the soap solution. The crimson color, as you remember, indicates that we have a foundation in front of us. Or, as chemists often say, this solution has an alkaline reaction (alkalis are the most common and very active bases; we try not to deal directly with them, because they are very caustic).

It has long been known that soap, when dissolved, interacts with water and forms, albeit weak, but alkali. And they thought that this is why soap removes dirt from hands and linen. And washing soda also gives an alkaline solution, and it also washes clothes well, especially if you boil it properly ...

But everything turned out to be wrong. Moreover, everything turned out to be the opposite. Soda erases because, when combined with dirt (and this is most often some kind of fat), it forms substances like soap.

So come on and you and I will get soap from soda, but not in a basin during washing, but in advance, in a test tube or in a glass.

Heat some water in a saucepan and pour washing (soda ash) into it in portions, stirring constantly. When the soda ceases to dissolve, you will have at your disposal a strong, as they say, concentrated solution of it. When hot, carefully pour it into a small, but always thin-walled flask, preferably in a test tube. With a pipette, drop by drop, add vegetable oil until it no longer dissolves. Oil can be replaced with melted wax, but then, of course, you can’t drip it with a pipette.

Soap was formed in the flask, but so far it is in liquid form. At a soap factory, such soap is salted out, that is, salt (the most common, table salt) is added to the solution. Do exactly the same. One or two pinches of salt and solid soap will float to the surface. Carefully remove it and test it - how it lathers, whether it forms foam, what kind of reaction it has with phenolphthalein.

Unfortunately, from the substances that we have at our disposal, good soap that can be washed and washed cannot be made. Now, if only from stearin ...

Take some fragments from a stearin candle (there are also paraffin candles, they are not suitable for this experiment). Heat the fragments in a thin glass placed in very hot water. When the stearin is melted, add a strong solution of washing soda. This is where the white mass will appear. This is soap. Let it stand for a few more minutes in hot water, and then carefully so as not to burn yourself (put on gloves), pour it into a matchbox. When the mass hardens, you will have a bar of soap that can be used for washing.

And you can put the experiment "on the contrary": make a candle from a bar of soap. Sliced ​​with a laundry soap knife, put the chips in a well-washed tin can, pour in water and heat, preferably in a water bath, not forgetting to stir all the time with a wooden stick. As soon as the soap dissolves, add vinegar to it - and a white mass will float to the surface. It's stearin. When the jar cools, it will collect on the surface. Scoop it up with a spoon, put it in a clean bowl, rinse with water and wrap it in a tissue or filter paper to dry the stearin. Now make a candle out of it.

Take a thick thread (for example, from a kerosene wick) and lower it into the heated and melted stearin. Take out the wick, let the stearin harden, and lower it back into the molten mass. Do this until the candle grows on the wick. And for simplicity, you can coat the wick once with a freshly prepared, still warm mass - and the soap candle is ready.

But back to soap. Why does it wash anyway? The trick is that the "head" and "tail" of the soap molecule are very different from each other. One end of the molecule (let it be the "head") easily combines with fats and other similar substances. And the other end (that is, the "tail") has the same love for water. Having run into a particle of dirt, the soap molecules are attached to it with their "heads", forming something like hedgehog needles. And the water, grabbing the "tails", pulls the particles of dirt in different directions and takes them away with it. So dirty becomes clean.

Alas, molecules cannot be seen with the eye, so you'll have to take my word for it. But we will still see something.

For example, here's what. Fill three identical bubbles halfway with water, but different: the first bubble - rain or from melted snow (you can scrape frost from the freezer), the second - ordinary, tap water, the third - mineral, from a bottle. If there is no mineral water, then add a tablespoon of calcium chloride solution or half a teaspoon of bitter salt to ordinary water - depending on what you have left in stock from old experiments. Separately, in a thin-walled glass, dissolve a little soap in hot water. It is more convenient to take soap flakes (about a tablespoon without top in half a glass of water); if there are no ready-made flakes, cut with a knife from a bar of laundry soap. Stir well so that the solution is clear.

Now the experience itself. Drop by drop into the first bottle of soapy water. Shake well after each drop and watch for foam. Don't forget to count the drops. As soon as the foam becomes lush and stable, stop dripping. Write down the number of drops and move on to the next bubble. You will see that tap water needs more soap than rain water to foam, and mineral water even more.

This is why it happens. There are almost no dissolved impurities in rain (or snow) water, but they are in tap and mineral water, and there are especially many of them in mineral water: they give it healing properties. The impurities of interest to us are salts, but not sodium, like table salt, but calcium and magnesium. Water with such salts is called hard, without them - soft.

By counting the drops of the same soap solution spent to produce foam, you can compare the hardness of water from different sources: for example, from a well, a pond, a river. Compare also boiled water with raw water: when boiled, the hardness of water decreases, but, unfortunately, does not disappear.

Hardness salts can be seen with your own eyes. To do this, all the water must be evaporated, at least on a candle flame. Carefully hold an old teaspoon filled with water over the flame (take water in turn from different sources), and compare how much sediment remains in different cases. Do not forget after each evaporation to properly wash the spoon from sediment.

Soap in hard water reacts with calcium and magnesium salts - the same ones that remained in the spoon - and loses all its cleaning ability. Dissolve in a bowl of water a few tablespoons of bitter salt or dry sea salt (also sold in pharmacies). Now try to wash some dirty patch in such water with soap and see if there will be any sense from this undertaking.

And now, in exactly the same water, pour a little washing powder - any that is found at home. And immediately there will be a good foam. The patch will instantly become clean, you just need to rub it lightly. Because washing powders, unlike soap, are not afraid of hard water. Salts do not harm them, they wash off dirt even in sea water.

However, not every washing powder is suitable for all washing occasions. A powder solution, like a soap solution, is also alkaline, and in this case it is good for cotton and linen, but not for wool and silk. And if doubts suddenly arise whether it is possible to wash, say, a woolen sweater with some kind of powder, then you can resolve this issue without outside help. Dissolve some powder in water and drop phenolphthalein. The solution turned red - it means that it contains alkali, and it is dangerous for wool; did not turn red or become slightly pink - there is no danger.

In the old days, there were no laundry detergents, and ordinary soap was considered a luxury item. Then various other substances were taken for washing: the same soda, the ashes of some trees, vegetable decoctions. They are far from soap, but still they washed.

The roots of some plants contain substances that act like soap (there was even such an expression - "soap root"). Try a decoction of cyclamen or primrose roots, common indoor plants, as well as crow's eye and cockle, growing in the middle lane. However, for the sake of simplicity, you can take a decoction of beans or mustard powder. Needless to say, mustard does not compete with washing, but still lathers ...

From washing it is just a step to another chemical procedure - cleaning.

There will be no long explanations for these experiments: although the goal is new (stain removal), the means are old and already familiar - extraction and oxidation. Let's say fat spots. They can be removed by extraction, choosing a good solvent - gasoline or turpentine. But please remember: such solvents are flammable! There must be no fire nearby!

With a greasy stain, you need to do this: moisten a cotton swab with a solvent, wipe it several times, and the fat will go into solution. Which is what we needed. However, a blurred mark may remain on the fabric. Wipe it with a solution of washing powder, rinse with water and let dry.

I hope you will guess for yourself that for the sake of such experiments it is not necessary to put stains on clothes. In general, it’s better not to immediately clean your suit or coat (it doesn’t matter if it’s yours or someone else’s). Prepare a few scraps of fabric, put spots on them and practice. The experiments will end successfully - move on to more serious matters. But keep in mind that some fabrics can be destroyed or change color under the influence of certain solvents. Therefore, somewhere from the inside, first check whether the fabric deteriorates during such cleaning. Miracles are miracles, but caution, you know, does not hurt.

It is difficult to remove oil paint with one solvent (although it is possible if the stain is very fresh). Moisten the stain with turpentine until softened, and then remove with gasoline. And in this case, do not forget to pre-check the fabric.

With ink on clothes, things are more complicated. Here you will need a little (a few drops) of alcohol - it dissolves the dyes that are part of the ink. But one extraction is still not enough. Adsorption will also have to be involved. Pour a little crushed chalk or tooth powder on the stain, drop a little alcohol, and when the chalk absorbs, adsorbs the ink, remove it with a dull knife. If you repeat the procedure several times, the chalk will eventually stop staining, which means that it has completely absorbed the ink. Shake off the remains of the dried chalk with a brush - and that's it.

And what about the promised oxidation? At least this way: if juice was spilled on a white cloth or a crushed berry got on it, then hydrogen peroxide with the addition of a few drops of ammonia will help. Moisten a cotton swab with the solution, wipe the stain, rinse with clean water - and the stain will most likely disappear. But do not try to smear colored fabrics with hydrogen peroxide! This is a very strong oxidizing agent, and, quite possibly, along with the stain, the peroxide will also remove the paint from the fabric.

If iodine, which was used to lubricate the wound, got on the clothes, then let me remind you: you have already experimented with iodine and sodium hyposulfite. Then the hyposulfite decolorized the iodine in the vial; now he will take it out of the fabric without a trace. In this reaction, oxidation also occurs, only the role of the oxidizing agent was taken over by iodine from the stain.

Since we are talking about iodine, let's use it to perform one very useful miracle: draw with iodine tincture on the gland. Rather, we will make indentations in the gland, as if scratching it. This process is called pickling and is often used in factories; only they take for this purpose not iodine, but other substances that act even more strongly.

Let, for example, you decide to write your name on your own penknife. Please! The place where the inscription will be, wipe it properly with sandpaper so that the surface shines. Light a candle and tilt it so that a few drops fall on the surface of the metal. Slightly heat the knife, then the stearin or paraffin from which the candle is made will spread in a thin layer. When it hardens, scratch a name (or a drawing, if you want) on it with a needle, be sure to go all the way to the metal. Drop a pharmacy iodine tincture into the grooves from a pipette. A few minutes later, the solution will noticeably turn pale, then drop another portion of iodine. Do not touch the knife for about an hour, then erase the traces of the candle and wash it properly. Scratch marks will remain on the iron surface.

Of course, for this experience it is not necessary to take a knife, you can take, say, a bicycle wrench or any other iron object. But why a candle?

Then, that she prevented iodine from reacting with iron. And in the scratches where the reaction took place, a new substance was formed - iron iodide, a loose powder that is easily removed from the surface.

By the way, iodine poisons not only iron, but also copper and copper alloys, such as brass, from which door handles are made. Good things should not be poisoned, but obsolete ...

If a copper or brass thing (quite good) has darkened over time and covered with a greenish coating - how to clean it? Housewives know: you need to rub it with ammonia or a gruel of ammonia and copper. But why?

Wrap a piece of red copper wire around a pencil or clamp it in a clothespin, make a small spiral at the other end of the wire. Hold this spiral in the flame. Pretty soon the surface will be covered with a black coating. It is the oxygen in the air that, when heated, oxidizes the copper, and it turns into copper oxide. Immerse another hot wire into a bottle of ammonia. There will be a hiss, and the spiral will again become shiny and red. The copper oxide decomposed, re-forming pure copper. It is clear why housewives use ammonia for cleaning? And they add tooth powder so that it absorbs dirt. You remember, this is called adsorption.

Repeat this experiment several times, and the liquid in the bottle will gradually turn blue. A very complex substance is formed there, like the one that helped us distinguish ammonia from other substances.

Blackened copper wire can be cleaned in another way. Immerse the heated coil in pharmaceutical hydrochloric acid (it is not dangerous because it is highly diluted). Copper will again become shiny, and the liquid will become blue. Another option: touch the ammonia (ammonium chloride) poured onto the bottom of the vial with a hot spiral. A cloud of white smoke will rise - this is ammonia evaporating - and the spiral will once again sparkle like new. Try lowering a blackened spiral into a bottle with a little cologne poured into the bottom. The alcohol contained in the cologne will also return her former red color.

But why do housewives prefer ammonia? Yes, because it works without heating. Although slower.

A little more about cleaning. But not door handles, but a washbasin in the bathroom. Or some earthenware. It happens that you can’t wash it right away, and then you rub, rub the old dirt, but it doesn’t leave.

However, the washbasin can be cleaned without any effort. But before you take on it, practice on an old plate or on an enameled bowl. The dirtier the better.

Potassium permanganate ("potassium permanganate") pour a small amount of vinegar and smear dirty places with this mixture. If you think that vinegar smells unpleasant, replace it with citric acid - mix it with permanganate equally and add water.

Leave the object that you smeared with the mixture for half an hour, and then wash it with water. The dirt has indeed gone somewhere (you and I know - it was oxidized by "potassium permanganate"). But how dirty everything is now with some kind of brown coating! Perhaps even scarier than before the experience.

Trivia. You already know how to deal with this dirt. Do you remember how you removed the stains from "potassium permanganate"? Do the same now. Pour a little citric acid into hydrogen peroxide and stir (you can add it to peroxide and vinegar). Take this liquid on a cotton swab or rag and calmly, without effort, swipe it over the soiled places. They will shine again, as if there were no brown spots. And most importantly, pay attention: you don’t need to rub or peel ...

In fact, in this way you can clean not only faience washbasins and plates, but also bathtubs and enameled pots. However, with frequent use, acid can damage the enamel. So, if the pan is very dirty, you can sometimes clean it with "potassium permanganate". But in other cases, it is better to take those cleaning products that are sold in stores.

I don’t know if you noticed or not, but during some chemical reactions - including those accompanied by oxidation - heat is released. Sometimes this is only beneficial, since when heated, many reactions go much faster. Sometimes to the detriment, since the reaction at an elevated temperature can go completely wrong, as intended, and then the mixture of substances has to be cooled. And there are cases when the reaction is carried out specifically in order to release heat. The most obvious and understandable example is burning: firewood in a stove, gas in a boiler room, gasoline in a car engine, fuel oil in a furnace of a thermal power plant.

Come on and we'll get heat through a chemical reaction. And we will not throw this heat into the wind, but we will try to use it. I propose to build a chemical heating pad.

In fact, there are many different chemical heating pads. Some of them are sold in stores that sell goods for hunters and fishermen. But to make such devices, we, perhaps, are beyond our power - and the design is complex, and not all substances can be bought. So let's do something faster.

Take a small glass jar, for example from under mayonnaise, and put an aluminum wire bent into a spiral into it. The wire should fit well against the walls, and then it should be bent so that more aluminum enters the glass jar.

Prepare a mixture that will react with aluminum. Three teaspoons of blue vitriol mix well with two teaspoons of table salt; I remind you that you need to use a spoon specially allocated for experiments, and not the one that is eaten. It may happen that large grains, several millimeters in size, will fall into the mixture. Rub them with a spoon, otherwise the future reaction may slow down.

Add about 30 g of sawdust to a mixture of salt and vitriol. Since sawdust is light, it takes a long time to measure them with a teaspoon. The required amount is about five tablespoons, or two handfuls. Stir the substances properly and fill the jar with aluminum wire with the mixture, but not to the very top, but a centimeter or two below. Because we still need to pour water into the jar - without it, the heating pad will not start working.

Now the main operation: pour a quarter cup of water into the jar (if this turns out to be too much, and part of the water is not absorbed by the sawdust, immediately drain the excess water). Wait a little, literally a minute or two, and the heating pad will begin to radiate heat. Very soon the temperature will reach about 50°C. And for another two hours after that, the chemical heating pad will be warm.

In a glass jar filled with a mixture, several chemical reactions take place at once. When you know chemistry better, you can easily figure out what happens to aluminum there. In the meantime, we will be satisfied with the result: the heating pad warms, and this is the main thing.

Before we finish the chapter and move on to other chemical marvels, perhaps not so useful, but no less interesting, let's set up one more experiment, which, probably, will come in handy someday. Let's make a frosty pattern on the glass. Even in summer.

Pour warm water into a bottle, not very much, not more than a tablespoon. In small portions, each time stirring well, pour ammonia (ammonium chloride). As soon as it stops dissolving, apply the solution with a brush on a piece of glass or on a mirror (watch out, don't cut yourself!). Now you have to wait until all the water has evaporated. And when there is no water left, a pattern will appear on the glass, very similar to frosty. Only instead of ice - crystals of ammonium chloride. They are not afraid of heat, but make sure that water does not get on them. A few drops - and the end of the miracle.

Author: Olgin O.M.

 We recommend interesting experiments in physics:

▪ Soap bubble electrification

▪ Pendulum and tricycle

▪ The glass is creeping!

 We recommend interesting experiments in chemistry:

▪ Extraction

▪ Getting carbon dioxide from lemonade or mineral water

▪ Summer wonders

See other articles Section Entertaining experiences at home.

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