Experiments with copper wire. Experiments with copper sulfate at home. How to make a crystal: stages of work

Interaction of metals with salts

Active metals displace less active metals from salts (metals are arranged in descending order of activity in the voltage series).

Let's conduct an experiment with a solution of divalent copper sulfate CuSO 4. In one flask with the solution we will put pieces of zinc Zn, in the other - steel buttons (steel is an alloy based on iron Fe). What will happen in a few hours? The solutions changed color, which means there is no more copper sulfate left there. Active metals - zinc and iron - replaced copper in the sulfate and formed salts. Zinc and iron were oxidized, and copper was reduced.

CuSO 4 + Zn = Zn SO 4 + Cu

CuSO 4 + Fe = Fe SO 4 + Cu

In one flask, copper was released on the buttons, in the other - on pieces of zinc. There were different metals in the flasks, so the copper deposit looks different. On zinc, copper separated out in the form of a loose brown mass. On iron buttons, the copper deposit is denser and pink in color.

Equipment: flasks.

Safety precautions. Careful handling of copper salts is necessary. Copper salts in high concentrations are poisonous. They require compliance with the rules for working with toxic substances. Beware of contact of copper salts with the skin and mucous membranes.

Setting up the experiment– Elena Makhinenko, text– Ph.D. Pavel Bespalov.

The interaction of tin chloride (II) with zinc (“Tin hedgehog”)

More active metals can replace less active metals from solutions of their salts. Pour a solution of tin (II) chloride into a glass and place a zinc plate into the solution. After some time, the plate becomes covered with a beautiful “fluffy” coating of tin. Tin was reduced from a solution of its salt by a more active metal - zinc:

SnCl 2 + Zn = Sn + ZnCl 2

Equipment: beaker, glass rod.

Safety precautions. The experience is safe.

Experiment setting and text– Ph.D. Pavel Bespalov.

Demonstration of the properties of Wood's alloy.

Wood's alloy consists of four components. It contains 50% bismuth, 25% lead, 12.5% tin and 12.5% cadmium. Place the alloy granules in hot water. It turns into a liquid state. This is a low-melting alloy. The melting point of the alloy is about +70 °C. Meanwhile, the melting point of tin is +232 °C, cadmium +321 °C, bismuth +271 °C, lead +327 °C. The melting point of the alloy differs from the melting temperatures of the metals included in its composition.

Equipment: beaker, tripod, burner, tweezers.

Safety precautions. Follow the rules for handling heating devices.

Experiment setting and text– Ph.D. Pavel Bespalov.

Platinum is a catalyst for hydrogen combustion

At ordinary temperatures, hydrogen very rarely enters into chemical reactions. Hydrogen does not react with oxygen either. But if you direct a stream of hydrogen at finely crushed platinum, the hydrogen ignites. This property of platinum was used in the so-called “Döbereiner hydrogen flint,” which was used to produce fire. Let's get hydrogen in the Kiryushkin apparatus, which is similar in principle to the Kipp apparatus. Let's check the hydrogen for purity. To do this, fill the test tube with the released hydrogen and bring the test tube to the burner flame. A quiet pop indicates the purity of the hydrogen being released. Using tweezers, take some platinized asbestos (asbestos with finely crushed platinum applied). Let's direct a stream of hydrogen at platinized asbestos. The asbestos becomes hot and the hydrogen ignites.

2H 2 + O 2 = 2H 2 O

Equipment: Kiryushkin apparatus, test tube, tweezers, burner.

Safety precautions. Follow the rules for working with flammable gases. Hydrogen can only be used after testing for purity.

Experiment setting and text– Ph.D. Pavel Bespalov.

Autoignition of nickel in air

Nickel is a durable, corrosion-resistant metal that does not change under the influence of atmospheric oxygen and moisture. Nickel is used to cover parts of devices and machines to give a decorative appearance and protect against corrosion. But crushed metals, including nickel, differ in their properties from metals in monolithic form. Let's isolate nickel from a nickel-aluminum alloy by placing the alloy powder in an alkali solution.

Aluminum reacts actively with alkali, dissolving in it, the reaction proceeds with the release of hydrogen. To increase the rate of aluminum dissolution, we heat the solution. When the reaction is over and all the aluminum has gone into solution, we rinse the resulting nickel crumbs first with water and then with ethyl alcohol to remove any remaining moisture. Let's extract some nickel chips from the alcohol onto filter paper. When the alcohol evaporates, the nickel begins to react with oxygen in the air, gradually heats up and burns to form nickel oxide.

2 Ni + O 2 = 2 NiO

Finely crushed iron also has similar properties. Crushed nickel and iron are pyrophores. Pyrophores are substances or mixtures of substances that ignite spontaneously in air.

Equipment: beaker, filter paper, tripod with mesh, glass rod.

Safety precautions. Follow the rules for working with alkalis and fire safety rules. Destroy all traces of pyrophoric nickel by dissolving them in dilute nitric acid.

Experiment setting and text– Ph.D. Pavel Bespalov.

Electrolysis of potassium iodide solution

Electrolysis is the decomposition of a substance under the influence of electric current. Electrolysis of potassium iodide occurs with the release of alkali, hydrogen and iodine:

2KI + 2 H 2 O = 2 KOH + H 2 + I 2

Let's prepare an electrolyzer filled with a solution of potassium iodide and two test tubes with the same solution. To detect alkali, add a phenolphthalein solution to one of the test tubes (this test tube is for the cathode), to detect iodine, add starch to the other test tube (test tube for the anode). Let's place the test tubes prepared in this way on the electrodes and turn on the current. In one of the test tubes at the cathode we observe the release of hydrogen, the solution in this test tube turns crimson: an alkali has formed in the test tube. A blue color appeared in the second test tube. In this test tube, iodine was released as a result of electrolysis. Iodine turns starch blue. We saw how, during the electrolysis of a solution of potassium iodide, iodine is formed, hydrogen gas and potassium hydroxide are released.

Equipment: test tubes, test tube rack, beakers, pipette, test tube holder, electrolysis device, beaker.

Safety precautions. Follow the rules for working with electrical appliances.

Setting up the experiment– Elena Makhinenko, text– Ph.D. Pavel Bespalov.

Electrochemical series of voltages - displacement of hydrogen by metals.

Metals differ in their chemical reactivity. Metals are arranged in descending order of activity in the voltage series:

Li, K, Ca, Na, Mg, Al, Mn, Zn, Fe, Co, Ni, Sn, Pb, H2, Cu, Hg, Ag, Au

Active metals (from lithium to lead) reduce hydrogen from acids, while inactive metals (from copper to gold) do not.

We will test four metals: magnesium Mg, aluminum Al, iron Fe and copper Cu. Let's prepare test tubes with a solution of hydrochloric acid (HCl) and immerse the metals in them. Copper does not react with hydrochloric acid solution. Iron slowly reduces hydrogen from an acid solution. Aluminum reacts more actively with hydrochloric acid solution, reducing hydrogen.

Magnesium most energetically reduces hydrogen from hydrochloric acid. We saw that metals that are in the electrochemical voltage series before hydrogen (iron, aluminum and magnesium) reduce it from acid solutions.

Metals in the row after hydrogen (copper in our experiment) do not reduce it from acids. The most active metal in our experiment was magnesium, the least active was copper.

2 HCl + Mg = MgC1 2 + H 2

2 HCl + Fe = FeC1 2 + H 2

6 HCl + 2Al = 2 A1C1 3 + 3H 2

Equipment:

Safety precautions. Follow the rules for working with acid solutions. Avoid contact of acids with skin and mucous membranes.

As a result of the reaction, a flammable gas is formed - hydrogen: there should be no open flame nearby.

Setting up the experiment– Elena Makhinenko, text– Ph.D. Pavel Bespalov.

Electrochemical voltage series of metals. Displacement of a metal from salt by other metals

Metals are arranged in descending order of activity in the voltage series:

Li, K, Ca, Na, Mg, Al, Mn, Zn, Fe, Co, Ni, Sn, Pb, H2, Cu, Hg, Ag, Au

Active metals displace less active metals from solutions of their salts. The first test tube contains copper (Cu) and a solution of a salt of a less active metal - silver (AgNO 3). The second pair is iron (Fe) and a solution of copper salt (CuSO 4). Iron is more active than copper. The third test tube contains zinc (Zn) and a solution of a salt of less active lead - Pb(NO 3) 2. Reactions begin in test tubes. After a while, we'll see what happens in the test tubes. The copper was covered with white silver crystals:

2 AgNO 3 + Cu = Cu(NO 3 ) 2 + 2 Ag

A pink coating of metallic copper appeared on the iron nail:

CuSO 4 + Fe = FeSO 4 + Cu

The zinc is covered with a loose layer of metallic lead:

Pb(NO 3) 2 + Zn = Pb + Zn (NO 3) 2

We are convinced that active metals displace less active metals from solutions of their salts.

Equipment: test tubes, test tube rack, funnel, tweezers.

Safety precautions. Lead salts and silver salts are poisonous; beware of contact with skin and mucous membranes. Silver nitrate solution leaves black stains on clothing and skin.

Setting up the experiment– Elena Makhinenko, text– Ph.D. Pavel Bespalov.

Experiments with copper wire

Several interesting experiments can be performed with copper, so we will devote a special chapter to it.

Make a small spiral from a piece of copper wire and secure it in a wooden holder (you can leave a free end of sufficient length and wrap it around a regular pencil). Heat the coil in a flame. Its surface will be covered with a black coating of copper oxide CuO. If a blackened wire is dipped into dilute hydrochloric acid, the liquid will turn blue, and the surface of the metal will again become red and shiny. The acid, if it is not heated, does not act on copper, but dissolves its oxide, turning it into the salt CuCl 2.

But here’s the question: if copper oxide is black, why are ancient copper and bronze objects covered not with black, but with a green coating, and what kind of coating is this?

Try finding an old copper object, say a candlestick. Scrape off some of the green residue and place it in a test tube. Close the neck of the test tube with a stopper with a gas outlet tube, the end of which is lowered into lime water (you already know how to prepare it). Heat the contents of the test tube. Drops of water will collect on its walls, and gas bubbles will be released from the gas outlet tube, causing the limewater to become cloudy. So it's carbon dioxide. What remains in the test tube is a black powder, which when dissolved in acid gives a blue solution. This powder, as you probably guess, is copper oxide.

So, we found out what components green plaque decomposes into. Its formula is written as follows: CuCO 3 * Cu(OH) 2 (basic copper carbonate). It forms on copper objects because there is always both carbon dioxide and water vapor in the air. The green coating is called patina. The same salt is found in nature - it is none other than the famous mineral malachite.

We will return to experiments with patina and malachite later - in the “Pleasant with useful” section. Now let's turn our attention again to the blackened copper wire. Is it possible to return it to its original shine without the help of acid?

Pour ammonia into a test tube, heat the copper wire red-hot and lower it into the vial. The spiral will hiss and again become red and shiny. In an instant, a reaction will occur resulting in the formation of copper, water and nitrogen. If the experiment is repeated several times, the ammonia in the test tube will turn blue. Simultaneously with this reaction, another, so-called complexation reaction occurs - the same copper complex compound is formed, which previously allowed us to accurately identify ammonia by the blue color of the reaction mixture.

By the way, the ability of copper compounds to react with ammonia has been used since very ancient times (even since those times when the science of chemistry was not even in sight). Copper and brass objects were cleaned with an ammonia solution, i.e., ammonia, to a shine. This, by the way, is what experienced housewives do now; for greater effect, ammonia is mixed with chalk, which mechanically scrubs away dirt and adsorbs contaminants from the solution.

Next experience. Pour a little ammonia-ammonium chloride NH 4 Cl into the test tube, which is used for soldering (do not confuse it with ammonia NH 4 OH, which is an aqueous solution of ammonia). Using a hot copper spiral, touch the layer of substance covering the bottom of the test tube. The hissing will be heard again, and white smoke will rise up - these are the particles of ammonia evaporating, and the spiral will again sparkle with its pristine copper shine. A reaction occurred, as a result of which the same products were formed as in the previous experiment, and in addition copper chloride CuCl 2.

It is precisely because of this ability - to restore metallic copper from the oxide - that ammonia is used in soldering. The soldering iron is usually made of copper, which conducts heat well; when its “tip” oxidizes, the copper loses its ability to hold tin solder on its surface. A little ammonia - and the oxide was gone.

And the last experiment with a copper spiral. Pour a little cologne into the test tube (even better - pure alcohol) and again introduce the hot copper wire. In all likelihood, you can already imagine the result of the experiment: the wire was again cleared of the oxide film. This time a complex organic reaction occurred: the copper was reduced, and the ethyl alcohol contained in the cologne was oxidized to acetaldehyde. This reaction is not used in everyday life, but sometimes it is used in the laboratory when an aldehyde needs to be obtained from alcohol.

Guys, we put our soul into the site. Thank you for that
that you are discovering this beauty. Thanks for the inspiration and goosebumps.
Join us on Facebook And In contact with

We take care of our children every day - we cook them porridge in the morning and iron their clothes. But in 20 years they will remember not our household chores, but the moments spent together.

website I have collected 16 experiments that will take adults away from their work and captivate children. They don’t require a lot of time or any special preparation, and you’ll have a lot of fun. And then you can cook the porridge. Together.

Solid liquid

You will need:

starch
Plastic container
food coloring, board, hammer and nails for additional experiments

Mix water and starch in a container until it reaches a creamy consistency. The result is a “non-Newtonian” liquid. You can easily sink your fingers into it, but if you hit the surface with your fist, you will feel that it is hard. Place a board on the surface of the liquid and you will easily drive a nail, but as soon as one corner of it is drowned in the liquid, the board will easily sink to the bottom. If desired, the “solid liquid” can be colored with food coloring.

DIY kinetic sand

You will need:

4 tsp. boric alcohol
2 tsp. office glue
1 tsp. dye
100 g sand for chinchillas
glass bowl

Pour all the liquid ingredients into a bowl, add sand and mix thoroughly. Done, you can create!

Pharaoh snake

You will need:

sand
alcohol
sugar
matches
plate for "snake"

Pour sand into a plate in a heap, soak it in alcohol, and put a mixture of sugar and soda on top. Set it on fire. The “snake” grows up instantly!

Electric train made of wire and batteries

You will need:

a roll of thick copper wire (the more wire, the longer the “tunnel”)
1 AA battery
2 round neodymium magnets, matching the diameter of the battery
ordinary pen

Wind the wire around the handle to create a long spring. Attach magnets to both ends of the battery. Start the "train". He will drive himself!

Swing made from a burning candle

You will need:

candle
thick needle
lighter
two glasses
pliers

Cut off the bottom end of the candle by a centimeter and a half to free the wick. Hold a needle in pliers and heat it with a lighter, then pierce the candle in the middle. Place it on the edges of two cups and light both sides. Rock it slightly, and then the candle will begin to rotate on its own.

Rainbow of paper towels

You will need:

food colorings
paper towels
5 glasses

Place the cups in a row and pour water into the 1st, 3rd and 5th. Add red food coloring to the 1st and 5th, yellow to the 3rd, and blue to the 5th. Fold 4 paper towels into quarters to create strips, then fold them in half. Insert the ends into different glasses - one between the 1st and 2nd glasses, the second between the 2nd and 3rd, etc. In a couple of hours you can admire the rainbow!

Elephant toothpaste

You will need:

3/4 cup water
1 tsp. potassium permanganate
1 tbsp. l. liquid soap
hydrogen peroxide
glass flask
disposable gloves

Dissolve potassium permanganate in water, add liquid soap and pour the mixture into a glass flask. Carefully but quickly pour in the peroxide. Violent foam will splash out of the flask upward - real toothpaste for an elephant!

Very slow ball

You will need:

steel ball
transparent plastic container ball made of two halves
liquid honey

Place the steel ball in a container, pour in honey and launch the entire structure down the slide. Hmm, what if you try it with shower gel?

Smoke rings

You will need:

plastic bottle (0.5 l)
balloon
incense stick
lighter
scissors

Cut off the bottom of the plastic bottle and half of the balloon. Place the wide part of the ball onto the cut of the bottle. Insert the stick into the bottle, cover its opening with your hand and wait until it fills with smoke. Make smoky rings by sharply tapping the tense ball with your finger.

Self-inflating balloons

You will need:

4 plastic bottles
table vinegar
3 tbsp. l. soda
3 balloons
liquid food coloring

Cut off the top of a plastic bottle, pull all the balls one by one over the hole and pour a spoonful of soda into each ball through the resulting funnel. Pour vinegar onto the bottoms of the bottles, add some food coloring there, and carefully, so that the soda does not spill into the bottle, pull the balls over the holes. All you have to do is lift them up - the soda will spill out, react with the vinegar, and the balls will inflate on their own.

Vinegar soda rocket

You will need:

plastic bottle (2 l)
3 simple pencils
2 tbsp. l. soda
200 ml vinegar 9%
wide tape
wine stopper
paper towel

Make sure in advance that the cork fits tightly to the neck of the bottle. Tape the pencils to the top of the bottle so that it can stand. Pour vinegar into the bottle. Wrap the baking soda tightly in a paper towel and twist the ends tightly. Go outside, put a package of soda in a bottle and plug it with a cork, pressing one end of the package to the neck. Flip the rocket over, place it on the ground and run! Takeoff must be observed from 15–20 meters, no less.

Copper sulfate has a bright and rich blue color. The crystals made from it are especially beautiful. They can be an original gift for friends and family or a very interesting activity to create. Copper sulfate crystals will become an original decor for the room. So how can you grow them yourself? The basic manufacturing principles are described in this article.

This product is sold in agricultural supply stores. But when using it at home, it is worth remembering that copper sulfate is a toxic drug. It is used to kill pests in fields. Therefore, when working with it, follow safety precautions: work only with rubber gloves, do not inhale the vapors of the solution with it, avoid contact with mucous membranes and eyes. Be sure to wash your hands after each handling of the product and only under running water.

Important! Do not use tap water for this procedure. It contains chlorine, which will react with the product and reduce the quality of the finished crystal. If you don't have distilled water, then use boiled water.

Advice. Since the crystal will be transparent in color, use a thin but strong thread to grow it. It will not be visible in the finished product, but it will support the weight of the decor.

When you place the thread in the container, make sure that it does not touch the sides of the container or the bottom. This will disrupt the crystal structure.
Since the glass will have to be heated, use it with a thick base or use heat-resistant dishes.

Today there are two ways to grow crystals from copper sulfate. Although the principle is the same: the gradual formation of growths, the result is crystals with different structures. It will also take different times to grow.
The fast method involves the formation of a crystal in a short time. It is suitable for those who do not like to wait and need quick results. The whole process will take about a week. You will grow an elongated crystal with many small branches.
If you want to grow a large crystal, then you will need a longer period of time and patience. But you will end up creating an item that looks like a large gemstone.

Prepare a container with a capacity of half a liter. Pour 200 grams of powder into it and pour 300 ml of warm water. It should be on a sand stove. Mix the mixture well until the grains are completely dissolved.

Remove the container from the sand and place it on the table. Let the mixture cool. Tie a piece of vitriol to the thread - this will be the seed. Dip it into the liquid.

Make sure that the seed and thread do not touch the walls and bottom of the dish. When the mixture cools, the released salts will settle on the prepared base. For convenience, fasten the thread to a pencil, which you place on the surface of the container. It will hold the thread in a vertical direction.

After a day, remove the base and heat the container again. In this case, the powder that has settled to the bottom should completely melt. Cool the mixture and place the thread inside the container again. Cover with a lid and leave for 12 hours. In a day, you will grow a brush of crystals on a thread. Repeat the procedure until the desired size of decoration is formed.

For a specific crystal shape, use wire instead of a base. Bend it into any shape, such as a drop, and drop it into the mixture. But it also should not touch the walls and bottom of the container. In a week you will grow such a bright crystal.

Advice. To shape the edges of the crystal, lubricate them with oil if they are not needed to grow in a certain place.

You will get large crystals with a smooth surface when growing it using a long method. But for this you will need not only a lot of time, but also attention. With this method, the seed is important and small crystals will have to be removed.

Mix 110 g of powder with 200 g of warm water. Stir the solution well and set aside. Then stir it periodically until the powder grains are completely dissolved. Filter the resulting mixture. Use a cotton pad or paper filter for this.

Wash the container and pour the filtered solution into it.
Among the powder crystals, find the largest one with smooth edges. Tie it on a thread and lower it into a container. It should be located strictly vertically inside, without touching the inner surface. Use a cloth to prevent dust and debris from getting into the solution.

In this method, you do not need to take out the thread and heat the mixture. After 10 days the crystal will double in size. Continue growing it until you reach the desired volume.

As you can see, growing a crystal from copper sulfate is not difficult, the main thing is patience and compliance with safety rules.

All rights to content and design reserved. Copying of materials is permitted only with indication of the original source in the form of an active hyperlink that is not blocked from indexing by search engines!

A selection of simple experiments with copper sulfate at home

In the last article I talked about copper sulfate, what it is, where it is used and even how some people are treated with it (I just don’t know if they are cured?), and today I propose to do experiments with copper sulfate at home.

I have already talked about all these experiments in the “Let’s Let’s Let’s Know” section, so now, in fact, I’m just collecting them all together, since they are scattered in different articles.

At the beginning, as usual, I warn you about following safety rules!

Let me remind you that we will do almost all experiments (except one) with a solution of copper sulfate. To get it, dissolve half a teaspoon in a glass of water - this is quite enough for all today's experiments. I suggest starting with the simplest thing and using a nail.

It’s all very simple – drop a clean (meaning without rust and oil) iron nail into the vitriol solution and wait. The chemical reaction will take place on its own, without your further participation. The first results will be visible within a few minutes. Well, I advise the most patient to “forget” about what is happening for a couple of weeks. It will be very interesting.

Drop a little ammonia into the light blue solution. Voila! A bright purple solution of copper ammonia is ready. Don't worry about the name, just enjoy the beautiful spectacle.

Add some sodium hydroxide. This produces a beautiful blue precipitate of copper hydroxide. Don't throw it away, we will need it in the next experiment.

You will need a pharmaceutical solution of pure glucose. We pour it onto the sediment obtained in the previous experiment and carefully heat it. The bright blue precipitate will gradually turn first into a yellow solution, then into a red one.

Everything needs to be done quite carefully and accurately, so look at how I did it.

Denaturation (destruction) of protein

Take a raw egg and separate the white from the yolk. Place the protein in a glass, add a little water, mix and divide into two parts, that is, into two experiments. Add a little copper sulfate to the first part. After mixing we get this incomprehensible mass:

To the second part of the protein add a little sodium hydroxide, and then a few drops of vitriol. We obtain a bright purple color of the solution.

Dilute a little ordinary table salt in a glass of water and mix with a solution of copper sulfate. We admire the emerald green color of the resulting solution.

It will require some preparation on your part (about five minutes), but it's worth it. All you need is an old frying pan and crystalline (not solution!) copper sulfate. We will use water to transform a white substance into a blue one. Detailed instructions here.

Even though it’s summer now, you can easily create real frosty patterns on glass.

Another very simple experiment. The only thing you will need is, as with the nail, patience. Well, a little ordinary stationery silicate glue. Details in the article “Chemical algae”.

Well, at the end of the day, a spectacular experience in obtaining foam. It can be done in two versions - with copper sulfate or potassium permanganate. In fact, the processes are the same and the result is also almost the same. True, you will have to run around pharmacies in search of hydroperite. If you are lucky and buy it, then carefully read this article and use it to your heart’s content!

That's all for today. I hope you find this collection of home experiments with copper sulfate useful. Maybe you have some ideas on what else can be done? Write in the comments and share your experience.

Good mood to you all!

P.S. I completely forgot about the most common experience - growing beautiful blue crystals. I promise to improve and show it to you soon

Svetlana Kalashnikova - chemistry teacher

Natalya, I came to the site by accident, for research work I am collecting information about table salt and sugar. I came in and stayed for a long time, I just couldn’t tear myself away, it was exactly what you needed, everything was interesting. We need to start a conversation, my email address is:

Nice to meet you, colleague!

You have successfully subscribed to the Kidschemistry.ru blog news

Entertaining experiments

Why do fruit knives turn black??!

Why do fruit knives turn black?

If you add an iron salt solution to some fruit juice (an iron salt solution can be easily obtained at home by dipping, for example, a nail or several buttons or paper clips in copper sulfate for half an hour), the liquid will immediately darken. We will get a solution of weak ink. Fruits contain tannic acid, which with iron salt forms ink. To obtain a solution of iron salts at home, dip a nail in a solution of copper sulfate and wait ten minutes. Then drain the greenish solution. The resulting solution of iron sulfate (FeSO 4) can be used in reactions.

Tea also contains tannic acid. A solution of iron salt added to a weak solution of tea will change the color of the tea to black. This is why it is not recommended to brew tea in a metal teapot!

Chemical reactions with table salt

Sometimes table salt is specially iodized, that is, sodium or potassium iodides are added to it. This is done because iodine is part of various enzymes in the body, and with its deficiency, the functioning of the thyroid gland worsens.

Solutions of copper sulfate with table salt (green)

The additive is quite easy to detect. You need to cook the starch paste: dilute a quarter teaspoon of starch in a glass of cold water, heat to a boil, boil for five minutes and cool. Paste is much more sensitive to iodine than dry starch. Next, a third of a teaspoon of salt is dissolved in a teaspoon of water, a few drops of vinegar essence (or half a teaspoon of vinegar), half a teaspoon of hydrogen peroxide and after two or three minutes - a few drops of paste are added to the resulting solution. If the salt has been iodized, then hydrogen peroxide will displace free iodine:

which will turn the starch blue. (The experiment will not work if KClO 3 was used instead of KI to iodize the salt). Can be carried out experiment with copper sulfate and table salt. None of the above reactions will occur here. But the reaction is beautiful. When mixing vitriol and salt, observe the formation of a beautiful green solution of sodium tetrachlorocuprate Na 2

Entertaining experiments with potassium permanganate:

Dissolve a few crystals of potassium permanganate in water and wait for a while. You will notice that the crimson color of the solution (explained by the presence of permanganate ions in the solution) will gradually become paler and then completely disappear, and a brown coating of manganese (IV) oxide will form on the walls of the vessel:

The dishes in which you conducted the experiment can be easily cleaned of deposits with a solution of citric or oxalic acid. These substances reduce manganese to the +2 oxidation state and convert it into water-soluble complex compounds. Solutions of potassium permanganate can be stored in dark bottles for years. Many people believe that potassium permanganate is highly soluble in water. In fact, the solubility of this salt at room temperature (20 °C) is only 6.4 g per 100 g of water. However, the solution is so intensely colored that it appears concentrated.

If you heat potassium permanganate to 200 0 C, then potassium permanganate will turn into dark green potassium manganate (K 2 MnO 4). This releases a large amount of pure oxygen, which can be collected and used for other chemical reactions. The potassium permanganate solution deteriorates (disintegrates) especially quickly in the presence of reducing agents. For example, the reducing agent is ethyl alcohol C 2 H 5 OH. Reaction of potassium permanganate with alcohol proceeds as follows:

Potassium permanganate detergent:

In order to get a homemade “detergent”, you need to mix potassium permanganate with acid. Of course, not with everyone. Some acids can themselves oxidize; in particular, if you take hydrochloric acid, toxic chlorine will be released from it:

This is how it is often obtained in laboratory conditions. Therefore, for our purposes, it is better to use diluted (about 5 percent) sulfuric acid. In extreme cases, it can be replaced with diluted acetic acid - table vinegar. Take approximately 50 ml (a quarter cup) of acid solution, add 1-2 g of potassium permanganate (at the tip of a knife) and mix thoroughly with a wooden stick. Then we rinse it under running water and tie a piece of foam sponge to the end. With this “brush” we quickly but carefully spread the oxidizing mixture over the contaminated area of the sink. Soon the liquid will begin to change color to dark cherry, and then to brown. This means that the oxidation reaction is in full swing. A few points need to be made here. You must work very carefully so that the mixture does not get on your hands and clothes; It would be nice to wear an oilcloth apron. And you should not hesitate, since the oxidizing mixture is very caustic and over time “eats” even foam rubber. After use, the foam “brush” should be immersed in a previously prepared jar of water, rinsed and discarded. During such cleaning of the sink, an unpleasant odor may appear, emitted by the products of incomplete oxidation of organic contaminants on the earthenware and acetic acid itself, so the room must be ventilated. After 15-20 minutes, wash off the browned mixture with a stream of water. And although the sink will appear in a terrible form - all covered in brown spots, there is no need to worry: the product of the reduction of potassium permanganate - manganese dioxide MnO 2 can be easily removed by reducing insoluble manganese (IV) to a manganese salt that is highly soluble in water.

But when potassium permanganate reacts with concentrated sulfuric acid, manganese oxide (VII) Mn 2 O 7 is formed - an oily dark green liquid. This is the only metal oxide that is liquid under normal conditions (tmelt=5.9°C). It is very unstable and easily explodes with slight heating (temperature=55°C) or with shock. Mn 2 O 7 is an even stronger oxidizing agent than KMnO 4. Upon contact with it, many organic substances, such as ethyl alcohol, ignite. By the way, this is one of the ways to light a spirit lamp without matches!

Entertaining experiments with hydrogen peroxide

Hydrogen peroxide can be both an oxidizing agent (this property is widely known) and a reducing agent! In the latter case, it reacts with oxidizing substances:

H 2 O 2 -2e → 2H + +O 2. Manganese dioxide is just such a substance. Chemists call such reactions “reductive decomposition of hydrogen peroxide.” Instead of pharmaceutical peroxide, you can use tablets of hydroperite - a compound of hydrogen peroxide with urea of the composition CO (NH 2) 2 H 2 O 2. It is not a chemical compound because there are no chemical bonds between the urea and hydrogen peroxide molecules; H 2 O 2 molecules are, as it were, included in long narrow channels in urea crystals and cannot leave there until the substance is dissolved in water. Therefore, such connections are called switch-on channel connections. One tablet of hydroperite corresponds to 15 ml (tablespoon) of a 3% solution of H 2 O 2. To obtain a 1% solution of H 2 O 2, take two tablets of hydroperite and 100 ml of water. When using manganese dioxide as an oxidizer for hydrogen peroxide, you need to know one subtlety. MnO 2 is a good catalyst for the decomposition of H 2 O 2 into water and oxygen:

And if you simply treat the sink with a solution of H 2 O 2, it will instantly “boil”, releasing oxygen, and the brown deposit will remain, because the catalyst should not be consumed during the reaction. To avoid catalytic decomposition of H 2 O 2, an acidic environment is needed. Vinegar will also work here. We strongly dilute the pharmacy peroxide with water, add a little vinegar and wipe the sink with this mixture. A real miracle will happen: the dirty brown surface will sparkle with whiteness and become like new. And the miracle happened in full accordance with the reaction

All that remains is to wash off the highly soluble manganese salt with a stream of water. In the same way, you can try to clean a dirty aluminum frying pan: in the presence of strong oxidizing agents, a strong protective oxide film is formed on the surface of this metal, which will protect it from dissolution in acid. But you shouldn’t clean enameled products (pots, bathtubs) using this method: the acidic environment slowly destroys the enamel. To remove MnO 2 deposits, you can also use aqueous solutions of organic acids: oxalic, citric, tartaric, etc. Moreover, there is no need to specially acidify them - the acids themselves create a fairly acidic environment in the aqueous solution.

Chemical reaction between potassium iodide and lead acetate

Of course, the gold is not real, but the experience is beautiful! For the Chemical reaction, we need a soluble lead salt (blue acetate (CH 3 COO) 2 Pb is suitable - a salt formed by dissolving lead in acetic acid) and an iodine salt (for example, potassium iodide KI). Lead acetate can also be obtained at home by dipping a piece of lead in acetic acid. Potassium iodide is sometimes used to etch electronic circuit boards

Potassium iodide and lead acetate are two transparent liquids that do not differ in appearance from water.

Let's start the reaction: add a solution of lead acetate to a solution of potassium iodide. By combining two transparent liquids, we observe the formation of a golden-yellow precipitate - lead iodide PbI 2 - spectacular! The reaction proceeds as follows:

Entertaining experiments with stationery glue

Stationery glue is nothing more than liquid glass or its chemical name is “sodium silicate” Na 2 SiO 3 You can also say it is a sodium salt of silicic acid. If you add a solution of acetic acid to silicate glue, insoluble silicic acid - hydrated silicon oxide - will precipitate:

The resulting H 2 SiO 3 precipitate can be dried in the oven and diluted with a diluted solution of water-soluble ink. As a result, the ink will settle on the surface of the silicon oxide and cannot be washed off. This phenomenon is called adsorption (from the Latin ad - “on” and sorbeo - “absorb”)

Another beautiful one fun experience with liquid glass. We will need copper sulfate CuSO 4, nickel sulfate NiS0 4, iron chloride FeCl 3. Let's make a chemical aquarium. Diluted aqueous solutions of nickel sulfate and ferric chloride are simultaneously poured from two glasses into a tall glass jar with silicate glue diluted in half with water. Silicate “algae” of yellow-green color gradually grow in the jar, which, intertwined, descend from top to bottom. Now let’s add a solution of copper sulfate drop by drop to the jar and populate the aquarium with “starfish”. The growth of algae is the result of the crystallization of hydroxides and silicates of iron, copper and nickel, which are formed as a result of exchange reactions.

Interesting experiments with iodine

Add a few drops of hydrogen peroxide H 2 O 2 to the iodine tincture and mix. After some time, a black shiny precipitate will separate from the solution. This crystalline iodine- a substance that is poorly soluble in water. Iodine precipitates faster if the solution is slightly warmed with hot water. Peroxide is needed to oxidize the potassium iodide KI contained in the tincture (it is added to increase the solubility of iodine). Another ability of iodine to be extracted from water by liquids consisting of non-polar molecules (oil, gasoline, etc.) is also associated with the poor solubility of iodine in water. Add a few drops of sunflower oil to a teaspoon of water. Stir and see that the oil and water do not mix. If you now drop two or three drops of iodine tincture into it and shake it vigorously, the oil layer will become dark brown in color, and the water layer will become pale yellow, i.e. Most of the iodine will go into the oil.

Iodine is a very caustic substance. To verify this, place a few drops of iodine tincture on a metal surface. After some time, the liquid will become discolored, and a stain will remain on the surface of the metal. The metal reacted with iodine to form a salt, iodide. One of the methods of applying inscriptions to metal is based on this property of iodine.

Colorful fun experience with ammonia

By “ammonia” we mean an aqueous solution of ammonia (ammonia). In fact, ammonia is a gas that, when dissolved in water, forms a new class of chemical compounds - “bases”. It is with the foundation that we will experiment. A spectacular experiment can be done with an ammonia solution (ammonia). Ammonia forms a colored compound with copper ions. Take a bronze or copper coin with a dark coating and fill it with ammonia. Immediately or after a few minutes the solution will turn blue. It was under the influence of atmospheric oxygen that copper formed a complex compound - ammonia:

Entertaining experiments: slaking lime

Lime slaking is a chemical reaction between calcium oxide (CaO - quicklime) and water. It proceeds as follows:

Calcium hydroxide (Ca(OH) 2) is also called lime milk. If you pass carbon dioxide through a solution of calcium hydroxide (or breathe into a tube through the solution), a white insoluble precipitate of calcium carbonate will form:

This reaction is also a qualitative reaction to calcium ions Ca+ in solution. The resulting substance - calcium carbonate - is the well-known chalk (lime, crayons)

Ignition temperature in air of some complex substances, 0 C:

Beginning of the reaction between magnesium and iodine. Release of iodine vapor

Iodine vapor and intense magnesium oxidation

The last stage of the reaction is the formation of magnesium iodide

Copper wire glows in the dark!

Complexity:

Danger:

Reagents

Safety

Before starting the experiment, put on protective gloves and goggles.
Conduct the experiment on a tray.

General safety rules

Do not allow chemicals to come into contact with your eyes or mouth.
Keep people away from the experiment site without protective glasses, as well as small children and animals.
Keep the experimental kit out of the reach of children under 12 years of age.
Wash or clean all equipment and fixtures after use.
Ensure that all reagent containers are tightly closed and stored properly after use.
Make sure all disposable containers are disposed of correctly.
Use only the equipment and reagents provided in the kit or recommended by current instructions.
If you have used a food container or glassware for experiments, throw it away immediately. They are no longer suitable for storing food.

First aid information

If reagents come into contact with your eyes, rinse thoroughly with water, keeping the eye open if necessary. Contact your doctor immediately.
If swallowed, rinse mouth with water and drink some clean water. Do not induce vomiting. Contact your doctor immediately.
If reagents are inhaled, remove the victim to fresh air.
In case of skin contact or burns, flush the affected area with plenty of water for 10 minutes or longer.
If in doubt, consult a doctor immediately. Take the chemical reagent and its container with you.
In case of injury, always seek medical attention.

Improper use of chemicals can cause injury and damage to health. Carry out only the experiments specified in the instructions.
This set of experiences is intended for children 12 years and older only.
Children's abilities vary significantly even within age groups. Therefore, parents conducting experiments with their children should use their own discretion to decide which experiments are appropriate and safe for their children.
Parents should discuss safety rules with their child or children before experimenting. Particular attention should be paid to the safe handling of acids, alkalis and flammable liquids.
Before starting experiments, clear the experiment site of objects that may interfere with you. Avoid storing food near the test site. The testing area should be well ventilated and close to a tap or other water source. To conduct experiments you will need a stable table.
Substances in disposable packaging must be used completely or disposed of after one experiment, i.e. after opening the package.

FAQ

The wire does not glow. What to do?

First, try waiting a little. The glow of the wire is not very bright, and perhaps your eyes simply did not have time to get used to the darkness. By the way, isn't it too bright around you? Remember that the darker it is, the more spectacular the experience!

Secondly, try dipping the wire into the solution again and rubbing it a little along the bottom of the glass. This will most likely help.

Thirdly, ignite the wire on a gas burner or turbo lighter. Copper, when interacting with oxygen, forms copper oxide CuO, which is necessary for our reaction to proceed.

Finally, add another 5 - 10 drops of luminol to the glass, stir and repeat step 6 of the instructions for the experiment.

Still not working? Perhaps the hydrogen peroxide H 2 O 2 has “fizzled out” a little and is no longer suitable for the experiment. You can buy a 3% medicinal solution of hydrogen peroxide at your local pharmacy.

Please contact our support team if you have any questions about this experiment.

Other experiments

Step-by-step instruction

Attention! For this experiment, you will need to ensure that the room is dark (starting from point 6 of these instructions). The darker it is around, the more impressive the “ghost” copper wire will look. Think in advance where it will be convenient for you to conduct the experiment.

Prepare a 3% solution of hydrogen peroxide H 2 O 2

Step-by-step instruction

Pour 5 ml of 2M sodium carbonate Na 2 CO 3 solution into the beaker from the starter kit.
Take an empty plastic test tube and fill it to the top with a 3% solution of hydrogen peroxide H 2 O 2.
Pour the contents of the test tube containing hydrogen peroxide into a beaker containing the sodium carbonate solution.
Add 10 drops of 1% luminol solution to a glass.
Bend a copper wire figurine as shown in the picture. You can make a free-form figurine, such as a treble clef. The main thing is that you feel comfortable holding the figurine by the long end of the wire. In addition, the experiment will be better if the figure is perpendicular to it.
Keep the room dark. Rub the wire along the bottom of the glass for 30 seconds.
Remove the wire from the glass and observe the glow. It may take a couple of minutes for your eyes to adjust to the darkness and for the glow to become bright.

Expected Result

Copper helps hydrogen peroxide H 2 O 2 oxidize luminol. As a result, the luminol solution remaining on the copper wire glows in the dark.

Disposal

Drain the solutions into the sink and rinse with excess water.

What happened

Why does the wire start to glow?

Luminol is a special compound. Under certain conditions, during its oxidation, light is released, that is, many very active particles called photons, which our eyes easily notice.

Why does the glow occur specifically on the wire? The fact is that one of the necessary conditions for the oxidation reaction of luminol to occur is the presence of a substance capable of taking electrons from luminol, and strictly one at a time. Copper is great for this. But since it is insoluble in water, the reaction can only occur in direct contact with this metal. So, the wire glows because the oxidation reaction of luminol occurs on its surface.

What happens to copper?

The copper wire glows both in the solution and outside (for some time). What explains this effect? All the necessary “actors” for the luminol oxidation reaction are able to approach the copper surface. If the wire remains in solution, an exchange is possible between the molecules that are on the surface of the copper and the molecules that float freely in the water. Therefore, the glow occurs for quite a long time. However, if you pull the wire out, this exchange will stop, the reaction will end along with it, and the glow will gradually fade away.

Copper itself is not consumed in this reaction, but it significantly contributes to its progress, or rather, accelerates it. Compounds that are not consumed in a reaction but increase its speed are called catalysts.

To learn more

How does electron exchange occur on the surface of copper? Please note: before the glow appears, you must rub the wire along the walls of the vessel. This is necessary in order to “expose” the surface of the copper, which in the initial state is covered with a thin layer of copper oxide CuO. The copper can then react with particles approaching it.

How does this happen? Let's imagine the surface of a copper wire: these are copper atoms connected to each other.

Next, some copper atom gets tired of the monotony of the metal lattice, he wants to explore his surroundings, get acquainted with new molecules, for example, water. Thus, the copper atom leaves the lattice in the form of a Cu + ion, leaving its electron inside.

But the copper ion cannot and does not want to go far from its “brothers”. Therefore, it actually travels in a thin (actually one atom thick) layer close to the surface of the wire. In fact, there are quite a lot of such “stray” ions on the surface of copper.

When there is a particle nearby that can donate electrons (for example, luminol), Cu + turns back into Cu 0 and returns to the metal lattice to its comrades. In total, luminol donates two electrons to copper ions. The “extra” electron is taken by hydrogen peroxide H 2 O 2. By doing this twice, it is converted into two hydroxyl anions OH -:

All these processes take place on the surface of the metal. Therefore, it is so important that the reacting substances, including luminol and hydrogen peroxide, have the opportunity to come into contact with copper.

Why is hydrogen peroxide needed?

Hydrogen peroxide H2O2, like water H2O, is a compound of hydrogen and oxygen. However, oxygen does not feel as comfortable in it as in water, and tries to get out of this state. Therefore, hydrogen peroxide can act as an oxidizing agent. It is she who ultimately oxidizes the luminol: it excites it so much that the luminol begins to glow.

Why is sodium carbonate needed?

Hydrogen peroxide H 2 O 2 may not be the weakest oxidizing agent, but it requires a special environment to perform its role. Everything must be carefully prepared, all the characters must be in place in order to take Luminol by surprise! And sodium carbonate is just another character thanks to which the reaction can proceed.

The oxidation of luminol with hydrogen peroxide, which ultimately leads to luminescence, occurs only in an alkaline environment, i.e. when there are quite a lot of OH - ions in the solution. This is exactly the environment that sodium carbonate Na 2 CO 3 creates.

To learn more

The appearance of an alkaline environment in a solution of sodium carbonate is due to the fact that carbonate ions CO 3 2–, which are obtained when this compound is dissolved, are able to interact with water. In this case, hydrocarbonate ions HCO 3 - and the same OH - ions are formed:

CO 3 2– + H 2 O<=>HCO 3 – +OH –

Why do we use copper?

Because copper is capable of removing electrons from luminol one at a time. Most metals prefer to go from metal to solution as a doubly charged cation, donating two electrons:

M → M 2+ + 2e –

However, copper is capable of donating one electron and stopping there, turning into the Cu+ form. All alkali metals, such as sodium Na or potassium K, also have this property. But they do this so actively that their reaction with water is accompanied by intense heating or even an explosion.

However, such one-electron exchange is also typical for silver:

Ag + + e – –> Ag

Ag – e – –> Ag +

Therefore, it can also be used in this experiment. It should be noted that other metals will also contribute to the glow, but it will be less intense than for copper or silver.

Development of the experiment

Glowing coin

Try the experiment with several different coins so you can compare the results. There is no need to prepare a new solution: all the necessary components are already in the beaker.

Take a coin and, using tweezers, a clamp or other convenient device, immerse it in the solution. You can rub it along the bottom of the glass. Don't forget to do the experiment in the dark!

Take a coin out of the glass. Does it glow? Compare different coins. Find out what metals were used in the minting (the process of making coins) for each coin.

Nail, paper clips and other candidates

Repeat the experiment (you can use the solution left over from the experiment with the glow of copper wire) with various small metal objects:

How else can you make copper glow?

In our case, the copper wire glowed due to a special oxidation reaction of luminol, in which copper acts as an accelerator, that is, a catalyst. However, there are other ways to make copper wire glow. True, it itself will serve exclusively as a metal base, without participating in the processes occurring on its surface. To do this, we can use special substances that glow not because of chemical reactions (such substances are called chemiluminescent), but because they are exposed to other light (photoluminescent substances). The phenomenon of a substance glowing under the influence of a light source is called photoluminescence. It comes in two types: fluorescence and phosphorescence.

You've probably come across bright poisonous green or orange clothes, which sometimes make your eyes dazzle. This effect occurs due to the fact that such tissues contain substances that can absorb visible light, enter a so-called excited state with increased energy, and then “calm down,” releasing the light back.

This light is in most cases bright and warm: orange, green, less often blue. This phenomenon is called fluorescence. The release of light occurs almost immediately after it is absorbed by the substance. The corresponding substances are called fluorescent. We can paint copper wire using a solution of this substance and it will glow.

If you place a fluorescent substance under the light of an ultraviolet lamp, the glow becomes much brighter. The fact is that the energy that a substance receives from a lamp is greater than from a conventional light source. Although fluorescent substances are very interesting because of their properties, they have an important drawback: unless light hits them, they cannot glow themselves.

You can recall popular children's toys that can glow in the dark. Such toys also contain substances that can absorb light and then release it. Moreover, the output is light of a certain color (most often it is green). An important difference between such substances and luminescent ones is that they are able to “charge” from light and gradually release the energy thus accumulated, rather than doing it all at once. They are called phosphorescent substances. They can also be applied to wire and it will glow.

Finally, many have probably heard about white phosphorus - a waxy substance that is also capable of glowing in the dark, as if by itself. In the 19th century, the properties of white phosphorus were actively used for various hoaxes and “frightening” effects. Remember, for example, the denouement of the brilliant Sherlock Holmes' investigation into the mystery of the Hound of the Baskervilles from the story of the same name by Sir Arthur Conan Doyle. The villain used white phosphorus!

However, white phosphorus does not glow on its own, but because of the oxidation reaction that occurs. Air oxygen acts as a substance that takes away electrons from it. That’s why it seems to us that white phosphorus glows on its own, without any external influence. The phenomenon of luminescence, which occurs due to the occurrence of a certain chemical reaction, is called chemiluminescence. We could also apply this substance to copper wire to make it glow in the dark, but we won't do that. White phosphorus extremely poisonous(poor dog of the Baskervilles!), and even professional chemists, equipped with all safety equipment, try to avoid working with it.