Interesting chemical experiments can be carried out using household items that are usually stored in a medicine cabinet at home. In this article we will talk about experiments with potassium permanganate and hydrogen peroxide.
What are peroxide and potassium permanganate?
These two reagents can be purchased at almost every pharmacy.
Hydrogen peroxide is the simplest peroxide with the formula H₂O₂. It is a colorless liquid with a faint odor that is soluble in water and some organic liquids. The substance is used in all spheres of life: in medicine, beauty and industry.
Hydrogen peroxide is usually sold in glass or plastic jars with a dispenser, and this substance has different concentrations: from 1-6 to 98 percent. Hydrogen peroxide produced in tablets is called hydroperite (in the tablet the peroxide is mixed with urea).
The same experiment can be repeated with hydroperite. To do this, you need to crush the tablets into powder and prepare a highly concentrated solution by mixing hydroperite with warm water. However, in this case the foam will not be so thick. The density of the foam and the intensity of the reaction depend on the soap used and the proportions, as well as on the concentration of peroxide (you can even use three percent, but instead of a snake you will just see abundant foam).
To make the experiment exciting, use food coloring and mix it with the soap.
When manganese and hydrogen peroxide are mixed, a large release of oxygen begins. Only in this case is it released into the detergent, thereby provoking an abundance of foam.
Hydrogen peroxide itself decomposes into oxygen, and potassium permanganate is only a catalyst that accelerates the process.
A drop of blood and hydrogen peroxide
Also, oxygen is released abundantly from peroxide when it comes into contact with blood, so when treating wounds you can see the rapid release of bubbles and hear hissing.
Hi all!
With this article I want to complete the “potassium permanganate” cycle and talk about several experiments that you can conduct yourself and show to your children, for example, when you tell them about this wonderful substance.
Experiments with potassium permanganate are, for the most part, simple and do not require any exotic reagents. Let me remind you that I originally created my blog in order to try out and publish experiments on it that are easy to do at home.
I have already described almost all of these experiments in various articles, now I will gather them together and generalize them.
Acid discoloration
You will need:
- Potassium permanganate,
- Vinegar essence,
- Hydrogen peroxide 3%
We make a pink permanganate solution, add 2-3 tablespoons of vinegar to it, and then 3-4 tablespoons of peroxide. The solution gradually brightens.
The reactions that occur are based on the properties of permanganate to discolor when interacting with acids. Therefore, it is recommended to scrub soiled items with various acids.
Discoloration with alkalis
You will need:
- Pink permanganate solution, as in the previous experiment,
- Concentrated solution of "Mole", that is, sodium hydroxide (what is it and how to make it).
We mix these two solutions and after a few minutes we observe how the color changes from pink to green. This, as in the previous experience, is associated with chemical properties potassium permanganate. In an alkaline environment (and sodium hydroxide solution is an alkali), manganese compounds have a green color.
A note slightly off topic. If you want to learn more about what acidic and alkaline environments are and how you can determine them yourself at home, here are articles about homemade indicators.
Change in color when interacting with components of tobacco smoke
One of my favorite experiences. They showed it to us back at the university on a subject like “ Environmental education“I don’t remember exactly.
I thought for a long time about how to replace the instruments and dishes that are in the university laboratory, but which are not at home, and finally came up with an idea. In my opinion, it turned out well and, most importantly, it was easy and clear.
Here are photographs of a solution of potassium permanganate before and after interaction with the “lungs” of a smoker:
The color change is due to the fact that tobacco smoke contains various substances: nitrogen oxides, pyridine, ammonia, aromatic amines, nicotine, tar (tobacco tar). They react with permanganate, changing its color.
Thermal decomposition of potassium permanganate
I don't really like this experiment. I have a bad attitude towards experiments with fire, flashes, etc., I can’t help it. 🙂
You will need:
- Dry potassium permanganate,
- Pharmacy glycerin,
- Heat-resistant stand.
Everything is described in detail in this article. General meaning– mix permanganate crystals with glycerin in the required proportions, and they will flare up.
Hydroperite decomposes under the influence of potassium permanganate
You will need:
- Hydroperite tablets.
- Potassium permanganate,
- Dishwashing liquid.
The experience is described in detail in this article, so I won’t repeat it. Let me just say that it is simple and effective. You just need to practice, choose the right concentrations - and you will get even more foam than you expected.
That's all for today. How did you like the experiments? Can you do them yourself?
I wish everyone a successful chemistry!
See you in the next article!
Natalia Bryantseva
Chemical experience - experiment - mix potassium permanganate and hydrogen peroxide. For this fun experiment you will need: 1. Potassium permanganate (potassium permanganate) - potassium permanganate, potassium salt of permanganate acid. Chemical formula - KMnO4. It is a dark purple, almost black crystal, which when dissolved in water forms a brightly colored solution of crimson color. 2. Hydrogen peroxide (hydrogen peroxide), H2O2 - 30%. Careful, don't touch! 3. Dishwashing liquid, or any well-foaming liquid (shampoo, liquid soap, bath foam, etc.). 4. Water, dyes. Reaction: when a solution of potassium permanganate and hydrogen peroxide interact, a lot of oxygen is released, which, together with the dishwashing liquid, produces a lot of foam! Use gloves! Don't touch with your hands! Conduct the experiment only in the presence of adults! More interesting experiments: Rubber egg = Egg + Vinegar https://www.youtube.com/watch?v=T9qLuSEsxNc Fire ball - how to make "non-burning, blessed fire" - https://www.youtube.com/watch?v=OMjmmt9SEzs Egg + Vinegar = Rubber Egg - https://www.youtube.com/watch?v=d0O7VWRHmUE Exploding an aluminum can from the inside https://www.youtube.com/watch?v=E7uNOlVArh4 Chemical investigation - experiment - mixing potassium permanganate and water peroxide. For this fun fact you will need: 1. Potassium permanganate (potassium permanganate) - potassium permanganate, potassium permanganate. Chemical formula - KMnO4. They are dark violet or even black crystals, which, when crushed in water, create a bright, raspberry-colored color. 2. Water peroxide (water peroxide), H2O2 - 30%. Be careful, don’t scratch! 3. A place to wash dishes, or maybe it would be nice to take a bath (shampoo, rare soap, bath soap, etc.). 4. Water, barnacles. Reaction: with the interaction of potassium permanganate and water peroxide, a lot of sourness is seen, which at the same time gives a lot of foam to the dishes! Vikorist mittens! Don't touch with your hands! Conduct investigations only in the presence of adults! Chemical experience - experiment - mix potassium permanganate and peroxide. For the purpose of this experiment, I will give you the following: Reactions: the use of solutions of manganese and peroxide will produce a lot of oxygen, which will result in a lot of foam! Get your fingers out! Be careful with your hands! The truth is that the experience is only for the gifted! Chemical experiment - a mixture of potassium permanganate and hydrogen peroxide. Reaction: interaction with a solution of potassium permanganate and hydrogen peroxide - all distributing a lot of oxygen, which also leads to a lot of heat! crawl away! Don't finish it! Punish the honey servant yourself in the presence of adults! music
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. In order to get a solution of iron salts at home, dip a nail in a solution of copper sulfate and wait about 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 colour)
The additive is quite easy to detect. You need to cook the starch paste: dilute a quarter teaspoon of starch in a glass 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:
2I - + H 2 O 2 +2CH 3 COOH→ I 2 +2H 2 O+2CH 3 COO - ,
which will color the starch Blue colour. (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:
4KMnO 4 +2H 2 O→ 4MnO 2 +4KOH+3O 2
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:
2КMnO 4 +3C 2 H 5 OH→ 2KOH+2MnO 2 +3CH 3 CHO+2H 2 O.
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:
2KMnO 4 +16HCl → 2MnCl 2 +5Cl 2 +2KCl+8H 2 O.
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 to the end foam sponge. 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 products of incomplete oxidation organic pollution on 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. Many will ignite upon contact with it. organic matter, for example ethyl alcohol. 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 is no hydrogen peroxide between the urea and hydrogen peroxide molecules. chemical bonds; 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 reaction of H 2 O 2 into water and oxygen:
2H 2 O 2 → 2H 2 O+O 2.
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
MnO 2 +H 2 O 2 +2H + → Mn 2+ +2H 2 O+O 2.
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 to clean similar method Enameled products (pots, bathtubs) should not be used: 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.
Entertaining experiments
"Gold" in a flask
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 acetic acid in lead are two transparent liquids, each appearance no different 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:
(CH 3 COO) 2 Pb+KI→ CH 3 COOK+PbI 2
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:
Na 2 SiO 3 + 2CH 3 COOH → 2CH 3 COONa + H 2 SiO 3 .
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. Yellow-green silicate “algae” gradually grow in the jar, which, intertwined, descend from top to bottom. Now let’s add a solution of copper sulfate to the jar drop by drop 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 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 new class 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 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:
2Cu+8NH 3 +3H 2 O+O 2 → 2(OH)
Entertaining experiments: slaking lime
Lime slaking is chemical reaction between calcium oxide (CaO - quicklime) and water. It proceeds as follows:
