Did you know that May 29 is Chemist's Day? Which of us in childhood did not dream of creating peculiar magic, amazing chemical experiments? It's time to turn your dreams into reality! Read on and we will tell you how to have fun Chemist Day 2017, as well as what chemistry experiments for kids are easy to do at home.
home volcano
If you are no longer attracted, then ... Want to see a volcanic eruption? Try making it at home! To arrange a chemical experiment "volcano" you will need soda, vinegar, food coloring, a plastic glass, a glass warm water.
Pour 2-3 tablespoons of table soda into a plastic cup, add ¼ cup of warm water and a little food coloring, preferably red. Then add ¼ of vinegar and watch the "eruption" of the volcano.
Rose and ammonia
A very interesting and original chemical experiment with plants can be viewed on a video from YouTube:
self-inflating balloon
Do you want to conduct safe chemistry experiments for children? Then you will definitely like the balloon experiment. Prepare in advance: a plastic bottle, baking soda, a balloon and vinegar.
Pour 1 teaspoon of baking soda inside the ball. Pour ½ cup of vinegar into the bottle, then put the ball on the neck of the bottle and make sure that the soda gets into the vinegar. As a result of a violent chemical reaction, which is accompanied by the active release of carbon dioxide, the balloon will begin to inflate.
pharaoh snake
For the experiment you will need: calcium gluconate tablets, dry fuel, matches or gas-burner. See the YouTube video for the steps:
color magic
Do you want to surprise a child? Rather, conduct chemical experiments with color! You will need the following available ingredients: starch, iodine, a transparent container.
Mix white starch and brown iodine in a container. As a result, you will get an amazing mixture of blue.
We grow a snake
The most interesting home chemistry experiments can be done using available ingredients. To create a snake, you will need: a plate, river sand, powdered sugar, ethyl alcohol, a lighter or burner, baking soda.
Pour a sand slide onto a plate and soak it with alcohol. In the top of the slide, make a recess where you carefully add powdered sugar and soda. Now we set fire to the sand hill and observe. After a couple of minutes, a dark wriggling ribbon will begin to grow from the top of the hill, which resembles a snake.
How to conduct chemical experiments with an explosion, see the following video from Youtube:
Home chemists-scientists believe that the most useful property detergents is the content of surfactants (surfactants). Surfactants significantly reduce the electrostatic voltage between the particles of substances and break down conglomerates. This feature makes it easier to clean clothes. In this article, chemical reactions that you can repeat with household chemicals, because with the help of surfactants you can not only remove dirt, but also conduct spectacular experiments.
Experience one: a foamy volcano in a jar
Spend this interesting experiment very easy at home. For him you will need:
hydroperite, or (the higher the concentration of the solution, the more intense the reaction and the more effective the eruption of the "volcano"; therefore, it is better to buy tablets at a pharmacy and dilute them in a small volume in a ratio of 1/1 immediately before use (you will get a 50% solution - this is an excellent concentration);
gel detergent for dishes (prepare approximately 50 ml of an aqueous solution);
dye.
Now you need to get an effective catalyst - ammonia. Carefully and drop by drop add the ammonia liquid until completely dissolved.
copper sulfate crystals
Consider the formula:
CuSO₄ + 6NH₃ + 2H₂O = (OH)₂ (copper ammonia) + (NH₄)₂SO₄
Peroxide decomposition reaction:
2H₂O₂ → 2H₂O + O₂
We make a volcano: mix ammonia with a washing solution in a jar or wide-necked flask. Then quickly pour in the hydroperite solution. The "eruption" can be very strong - for safety reasons, it is better to substitute some kind of container under the volcano flask.
Experience two: the reaction of acid and sodium salts
Perhaps the most common compound that is in every home is baking soda. It reacts with acid, and the result is new salt, water and carbon dioxide. The latter can be detected by hissing and bubbles at the reaction site.
Experience three: "floating" soap bubbles
This is a very simple experience with baking soda. You will need:
- aquarium with a wide bottom;
- baking soda (150-200 grams);
- (6-9% solution);
- soap bubbles (to make your own, mix water, dish soap and glycerin)
On the bottom of the aquarium you need to evenly sprinkle soda and pour it with acetic acid. The result is carbon dioxide. It is heavier than air and therefore settles at the bottom of the glass box. To determine if there is CO₂ there, lower a lit match to the bottom - it will instantly go out in carbon dioxide.
NaHCO₃ + CH₃COOH → CH₃COONa + H₂O + CO₂
Now you need to blow bubbles into the container. They will slowly move along a horizontal line (the boundary of contact between carbon dioxide and air invisible to the eye, as if swimming in an aquarium).
Experience four: the reaction of soda and acid 2.0
For experience you will need:
- different types of non-hygroscopic food products(e.g. gummies).
- a glass of diluted baking soda (one tablespoon);
- a glass with a solution of acetic or any other available acid (malic,).
Cut pieces of marmalade sharp knife into strips 1-3 cm long and place for processing in a glass of soda solution. Wait 10 minutes and then transfer the pieces to another beaker (with an acid solution).
Ribbons will be overgrown with bubbles of the resulting carbon dioxide and float to the top. On the surface, the bubbles will disappear, the lifting force of the gas will disappear, and the marmalade ribbons will sink, again overgrown with bubbles, and so on until the reagents in the container run out.
Experience five: properties of alkali and litmus paper
Most detergents contain sodium hydroxide, the most common alkali. It is possible to reveal its presence in a solution of a detergent in this elementary experiment. At home, a young enthusiast can easily conduct it on his own:
- take a strip of litmus paper;
- dissolve some liquid soap in water;
- dip the litmus into the soapy liquid;
- wait for the indicator to turn blue, which will indicate an alkaline reaction of the solution.
Click to find out what other experiments to determine the acidity of the environment can be carried out from improvised substances.
Experience six: colored explosions-stains in milk
The experience is based on the properties of the interaction of fats and surfactants. Fat molecules have a special, dual, structure: hydrophilic (interacting, dissociating with water) and hydrophobic (water-insoluble "tail" of a polyatomic compound) end of the molecule.
- Pour milk into a wide container of small depth (“canvas”, on which a color explosion will be visible). Milk is a suspension, a suspension of fatty molecules in water.
- With a pipette, add a few drops of water-soluble liquid dye to the milk container. You can add different dyes to different places of the container and make a multi-color explosion.
- Then you need to moisten a cotton swab in liquid detergent and touch the surface of the milk. The white "canvas" of milk turns into a moving palette with paints that move in the liquid like spirals and twist into bizarre curves.
This phenomenon is based on the ability of surfactants to fragment (divide into sections) a film of fat molecules on the surface of a liquid. Fat molecules, repelled by their hydrophobic "tails", migrate in the milk suspension, and with them the partially undissolved paint.
My personal experience of teaching chemistry has shown that such a science as chemistry is very difficult to study without any initial knowledge and practice. Schoolchildren very often run this subject. I personally observed how a student of the 8th grade at the word "chemistry" began to frown, as if he had eaten a lemon.
Later it turned out that because of dislike and misunderstanding of the subject, he skipped school in secret from his parents. Of course, the school curriculum is designed in such a way that the teacher must give a lot of theory at the first chemistry lessons. Practice, as it were, fades into the background precisely at the moment when the student cannot yet independently realize whether he needs this subject in the future. This is primarily due to the laboratory equipment of schools. AT big cities at present, things are better with reagents and instruments. As for the province, as well as 10 years ago, and at present, many schools do not have the opportunity to conduct laboratory classes. But the process of studying and fascination with chemistry, as well as with other natural sciences, usually begins with experiments. And it is no coincidence. Many famous chemists, such as Lomonosov, Mendeleev, Paracelsus, Robert Boyle, Pierre Curie and Maria Sklodowska-Curie (schoolchildren also study all these researchers in physics classes) have already started experimenting since childhood. The great discoveries of these great people were made in home chemical laboratories, since chemistry classes at institutes were available only to wealthy people.
And, of course, the most important thing is to interest the child and convey to him that chemistry surrounds us everywhere, so the process of studying it can be very exciting. This is where home chemistry experiments come in handy. Observing such experiments, one can further look for an explanation of why things happen this way and not otherwise. And when a young researcher encounters similar concepts at school lessons, the teacher’s explanations will be more understandable to him, since he will already have his own experience in conducting home chemical experiments and the knowledge gained.
It is very important to start science studies with the usual observations and real life examples that you think will be the best for your child. Here are some of them. Water is Chemical substance, consisting of two elements, as well as gases dissolved in it. Man also contains water. We know that where there is no water, there is no life. A person can live without food for about a month, and without water - only a few days.
River sand is nothing but silicon oxide, and also the main raw material for glass production.
A person himself does not suspect it and carries out chemical reactions every second. The air we breathe is a mixture of gases - chemicals. In the process of exhalation, another complex substance is released - carbon dioxide. We can say that we ourselves are a chemical laboratory. You can explain to the child that washing hands with soap is also a chemical process of water and soap.
An older child who, for example, has already begun to study chemistry at school, can be explained that almost all elements can be found in the human body. periodic system D. I. Mendeleev. In a living organism, not only all chemical elements are present, but each of them performs some biological function.
Chemistry is also medicines, without which at present many people cannot live even a day.
Plants also contain the chemical chlorophyll, which gives the leaf its green color.
Cooking is hard chemical processes. Here you can give an example of how the dough rises when yeast is added.
One of the options for getting a child interested in chemistry is to take an individual outstanding researcher and read the story of his life or watch an educational film about him (films about D.I. Mendeleev, Paracelsus, M.V. Lomonosov, Butlerov are now available).
Many believe that real chemistry is harmful substances, experimenting with them is dangerous, especially at home. There are many very exciting experiences that you can spend with your child without harming your health. And these home chemical experiments will be no less exciting and instructive than those that come with explosions, pungent odors and puffs of smoke.
Some parents are also afraid to conduct chemical experiments at home due to their complexity or lack of necessary equipment and reagents. It turns out that you can get by with improvised means and those substances that every housewife has in the kitchen. You can buy them at your nearest household store or pharmacy. Test tubes for home chemical experiments can be replaced with pill bottles. Reagents can be stored in glass jars, e.g. baby food or mayonnaise.
It is worth remembering that the dishes with reagents must have a label with the inscription and be tightly closed. Sometimes the tubes need to be heated. In order not to hold it in your hands when heated and not get burned, you can build such a device using a clothespin or a piece of wire.
It is also necessary to allocate several steel and wooden spoons for mixing.
You can make a stand for holding test tubes yourself by drilling through holes in the bar.
To filter the resulting substances, you will need a paper filter. It is very easy to make it according to the diagram given here.
For children who do not yet go to school or are studying in elementary grades, setting up home chemical experiments with their parents will be a kind of game. Most likely, such a young researcher will not yet be able to explain some individual laws and reactions. However, perhaps just such an empirical way of discovering the surrounding world, nature, man, plants through experiments will lay the foundation for the study of natural sciences in the future. You can even arrange original competitions in the family - who will have the most successful experience and then demonstrate them at family holidays.
Regardless of the age of the child and his ability to read and write, I advise you to have a laboratory journal in which you can record experiments or sketch. A real chemist must write down a work plan, a list of reagents, sketches of instruments and describes the progress of work.
When you and your child just begin to study this science of substances and conduct home chemical experiments, the first thing to remember is safety.
For this you need to follow the following rules security:
2. It is better to allocate a separate table for conducting chemical experiments at home. If you do not have a separate table at home, then it is better to conduct experiments on a steel or iron tray or pallet.
3. It is necessary to get thin and thick gloves (they are sold in a pharmacy or hardware store).
4. For chemical experiments, it is best to buy a lab coat, but you can also use a thick apron instead of a dressing gown.
5. Laboratory glassware should not be used for food.
6. In home chemical experiments, there should be no cruelty to animals and violation of the ecological system. Acidic chemical waste should be neutralized with soda, and alkaline with acetic acid.
7. If you want to check the smell of a gas, liquid or reagent, never bring the vessel directly to your face, but, holding it at a certain distance, direct, waving your hand, the air above the vessel towards you and at the same time smell the air.
8. Always use small amounts of reagents in home experiments. Avoid leaving reagents in a container without an appropriate inscription (label) on the bottle, from which it should be clear what is in the bottle.
The study of chemistry should begin with simple chemical experiments at home, allowing the child to master the basic concepts. A series of experiments 1-3 allow you to get acquainted with the basic aggregate states of substances and the properties of water. To begin with, you can show a preschooler how sugar and salt dissolve in water, accompanying this with an explanation that water is a universal solvent and is a liquid. Sugar or salt are solids that dissolve in liquids.
Experience number 1 "Because - without water and neither here nor there"
Water is a liquid chemical substance composed of two elements as well as gases dissolved in it. Man also contains water. We know that where there is no water, there is no life. A person can live without food for about a month, and without water - only a few days.
Reagents and equipment: 2 test tubes, soda, citric acid, water
Experiment: Take two test tubes. Pour in equal amounts of soda and citric acid. Then pour water into one of the test tubes, and not into the other. In a test tube in which water was poured, carbon dioxide began to be released. In a test tube without water - nothing has changed
Discussion: This experiment explains the fact that many reactions and processes in living organisms are impossible without water, and water also accelerates many chemical reactions. Schoolchildren can be explained that an exchange reaction has taken place, as a result of which carbon dioxide has been released.
Experience number 2 "What is dissolved in tap water"
Reagents and equipment: clear glass, tap water
Experiment: Pour into a clear glass tap water and put it in a warm place for an hour. After an hour, you will see settled bubbles on the walls of the glass.
Discussion: Bubbles are nothing but gases dissolved in water. AT cold water gases dissolve better. As soon as the water becomes warm, the gases cease to dissolve and settle on the walls. A similar home chemical experiment also makes it possible to acquaint the child with the gaseous state of matter.
Experience No. 3 “What is dissolved in mineral water or water is a universal solvent”
Reagents and equipment: test tube, mineral water, candle, magnifying glass
Experiment: Pour mineral water into a test tube and slowly evaporate it over a candle flame (the experiment can be done on the stove in a saucepan, but the crystals will be less visible). As the water evaporates, small crystals will remain on the walls of the test tube, all of them of different shapes.
Discussion: Crystals are salts dissolved in mineral water. They have different shape and size, since each crystal wears its own chemical formula. With a child who has already begun to study chemistry at school, you can read the label on mineral water, where its composition is indicated and write the formulas of the compounds contained in mineral water.
Experiment No. 4 "Filtration of water mixed with sand"
Reagents and equipment: 2 test tubes, funnel, filter paper, water, river sand
Experiment: Pour water into a test tube and dip a little river sand into it, mix. Then, according to the scheme described above, make a filter out of paper. Insert a dry, clean test tube into a rack. Slowly pour the sand/water mixture through a filter paper funnel. River sand will remain on the filter, and you will get clean water in a tripod tube.
Discussion: Chemical experience allows us to show that there are substances that do not dissolve in water, for example, river sand. The experience also introduces one of the methods of cleaning mixtures of substances from impurities. Here you can introduce the concepts of pure substances and mixtures, which are given in the 8th grade chemistry textbook. In this case, the mixture is sand with water, the pure substance is the filtrate, and river sand is the sediment.
The filtration process (described in Grade 8) is used here to separate a mixture of water and sand. To diversify learning this process, you can go a little deeper into the cleaning history drinking water.
Filtration processes were used as early as the 8th and 7th centuries BC. in the state of Urartu (now it is the territory of Armenia) for the purification of drinking water. Its inhabitants built plumbing system using filters. Used as filters dense fabric and charcoal. Similar intertwined systems downpipes, clay channels equipped with filters were also on the territory of the ancient Nile among the ancient Egyptians, Greeks and Romans. Water was passed through such a filter several times through such a filter, eventually many times, eventually achieving best quality water.
One of the most interesting experiments is growing crystals. The experience is very clear and gives an idea of many chemical and physical concepts.
Experience number 5 "Grow sugar crystals"
Reagents and equipment: two glasses of water; sugar - five glasses; wooden skewers; thin paper; pot; transparent cups; food coloring (the proportions of sugar and water can be reduced).
Experiment: The experiment should begin with the preparation of sugar syrup. We take a pan, pour 2 cups of water and 2.5 cups of sugar into it. We put on medium heat and, stirring, dissolve all the sugar. Pour the remaining 2.5 cups of sugar into the resulting syrup and cook until completely dissolved.
Now let's prepare the embryos of crystals - sticks. Scatter a small amount of sugar on a piece of paper, then dip the stick in the resulting syrup, and roll it in sugar.
We take the pieces of paper and pierce a hole in the middle with a skewer so that the piece of paper fits snugly against the skewer.
Then we pour the hot syrup into transparent glasses (it is important that the glasses are transparent - this way the process of crystal ripening will be more exciting and visual). The syrup must be hot or the crystals will not grow.
You can make colored sugar crystals. To do this, add a little food coloring to the resulting hot syrup and stir it.
The crystals will grow in different ways, some quickly and some may take longer. At the end of the experiment, the child can eat the resulting lollipops if he is not allergic to sweets.
If you do not have wooden skewers, then you can experiment with ordinary threads.
Discussion: A crystal is a solid state of matter. It has a certain shape and a certain number of faces due to the arrangement of its atoms. Crystalline substances are substances whose atoms are arranged regularly, so that they form a regular three-dimensional lattice, called a crystal. Crystals of a number of chemical elements and their compounds have remarkable mechanical, electrical, magnetic and optical properties. For example, diamond is a natural crystal and the hardest and rarest mineral. Due to its exceptional hardness, diamond plays a huge role in technology. Diamond saws cut stones. There are three ways to form crystals: crystallization from a melt, from a solution, and from a gas phase. An example of crystallization from a melt is the formation of ice from water (after all, water is molten ice). An example of crystallization from solution in nature is the precipitation of hundreds of millions of tons of salt from sea water. In this case, when growing crystals at home, we are dealing with the most common methods of artificial growing - crystallization from a solution. Sugar crystals grow from a saturated solution by slowly evaporating the solvent - water, or by slowly lowering the temperature.
The following experience allows you to get at home one of the most useful crystalline products for humans - crystalline iodine. Before conducting the experiment, I advise you to watch with your child a short film “The life of wonderful ideas. Smart iodine. The film gives an insight into the benefits of iodine and unusual story his discovery, which will be remembered for a long time by the young researcher. And it is interesting because the discoverer of iodine was an ordinary cat.
French scientist Bernard Courtois Napoleonic Wars noticed that in the products obtained from the ashes of seaweed, which were thrown onto the coast of France, there is some substance that corrodes iron and copper vessels. But neither Courtois himself nor his assistants knew how to isolate this substance from the ashes of algae. Chance helped speed up the discovery.
At his small saltpeter plant in Dijon, Courtois was going to conduct several experiments. There were vessels on the table, one of which contained an alcoholic tincture of seaweed, and the other a mixture of sulfuric acid and iron. On the shoulders of the scientist sat his beloved cat.
There was a knock on the door, and the frightened cat jumped down and ran away, brushing the flasks on the table with its tail. The vessels broke, the contents mixed, and suddenly a violent chemical reaction began. When a small cloud of vapors and gases settled, the surprised scientist saw some kind of crystalline coating on the objects and debris. Courtois began to explore it. Crystals to anyone before this unknown substance were called "iodine".
So a new element was discovered, and Bernard Courtois's domestic cat went down in history.
Experience No. 6 "Obtaining iodine crystals"
Reagents and equipment: tincture of pharmaceutical iodine, water, a glass or a cylinder, a napkin.
Experiment: We mix water with tincture of iodine in the proportion: 10 ml of iodine and 10 ml of water. And put everything in the refrigerator for 3 hours. During cooling, the iodine will precipitate at the bottom of the glass. We drain the liquid, take out the iodine precipitate and put it on a napkin. Squeeze with napkins until the iodine begins to crumble.
Discussion: The chemical experiment is called extracting or extracting one component from another. In this case, the water extracts the iodine from the spirit lamp solution. Thus, the young researcher will repeat the experience of the cat Courtois without smoke and beating dishes.
Your child will already learn about the benefits of iodine for disinfecting wounds from the movie. Thus, you show that there is an inextricable link between chemistry and medicine. However, it turns out that iodine can be used as an indicator or analyzer of the content of another beneficial substance- starch. The following experience will introduce the young experimenter to a separate very useful chemistry - analytical.
Experience No. 7 "Iodine-indicator of starch content"
Reagents and equipment: fresh potatoes, pieces of banana, apple, bread, a glass of diluted starch, a glass of diluted iodine, a pipette.
Experiment: We cut the potatoes into two parts and drip diluted iodine on it - the potatoes turn blue. Then we drip a few drops of iodine into a glass of diluted starch. The liquid also turns blue.
We drip with a pipette iodine dissolved in water on an apple, banana, bread, in turn.
Watching:
The apple didn't turn blue at all. Banana - slightly blue. Bread - turned blue very much. This part of the experience shows the presence of starch in various foods.
Discussion: Starch, reacting with iodine, gives a blue color. This property gives us the ability to detect the presence of starch in various foods. Thus, iodine is, as it were, an indicator or analyzer of starch content.
As you know, starch can be converted into sugar, if you take an unripe apple and drop iodine, it will turn blue, since the apple is not yet ripe. As soon as the apple ripens, all the starch contained will turn into sugar and the apple does not turn blue at all when treated with iodine.
The following experience will be useful for children who have already started studying chemistry at school. It introduces concepts such as chemical reaction, compound reaction, and qualitative reaction.
Experiment No. 8 "Flame coloring or compound reaction"
Reagents and equipment: tweezers, table salt, spirit lamp
Experiment: Take with tweezers a few crystals of coarse salt table salt. Let's hold them over the flame of the burner. The flame will turn yellow.
Discussion: This experiment makes it possible to carry out a chemical combustion reaction, which is an example of a compound reaction. Due to the presence of sodium in the composition of table salt, during combustion, it reacts with oxygen. As a result, a new substance is formed - sodium oxide. The appearance of a yellow flame indicates that the reaction has passed. Similar reactions are qualitative reactions for compounds containing sodium, that is, it can be used to determine whether a substance contains sodium or not.
This manual increases interest in the subject, develops cognitive, mental, research activities. Students analyze, compare, study and summarize the material, get new information and practical skills. Students can conduct some experiments on their own at home, but most in the classroom of a chemical circle under the guidance of a teacher.
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town Novomikhailovsky
municipality
Tuapse district
« chemical reactions around us"
Teacher:
Kozlenko
Alevtina Viktorovna
2015
« Volcano" on the table.Ammonium dichromate mixed with metallic magnesium is poured into the crucible (the mound in the center is moistened with alcohol). Light the "volcano" with a burning torch. The reaction is exothermic, proceeds rapidly, together with nitrogen, hot particles of chromium oxide (III) fly out and
burning magnesium. If you turn off the light, you get the impression of an erupting volcano, from the crater of which red-hot masses pour out:
(NH 4) 2 Cr 2 O 7 \u003d Cr 2 O 3 + 4H 2 O + N 2; 2Mg + O 2 \u003d 2MgO.
"Star Rain".Pour onto a sheet of clean paper, mixing thoroughly, three tablespoons of potassium permanganate, coal powder and reduced iron powder. The resulting mixture is poured into an iron crucible, which is fixed in the tripod ring and heated with the flame of an alcohol lamp. The reaction starts and the mixture is ejected
in the form of many sparks, giving the impression of "fiery rain".
Fireworks in the middle of the liquid. 5 ml of concentrated sulfuric acid is poured into the cylinder and 5 ml of ethyl alcohol is carefully poured along the wall of the cylinder, then a few crystals of potassium permanganate are thrown. Sparks appear on the border between two liquids, accompanied by crackling. Alcohol ignites when oxygen appears, which is formed when potassium permanganate reacts with sulfuric acid.
"Green Fire" . Boric acid with ethyl alcohol form an ester:
H 3 BO 3 + 3C 2 H 5 OH \u003d B (OS 2 H 5) + 3H 2 O
Pour 1 g into a porcelain cup boric acid, pour 10 ml of alcohol and 1 ml of sulfuric acid. The mixture is stirred with a glass rod and ignited. Ether vapor burns with a green flame.
Water ignites paper. In a porcelain cup, sodium peroxide is mixed with small pieces of filter paper. A few drops of water are dripped onto the prepared mixture. The paper is flammable.
Na 2 O 2 + 2H 2 O \u003d H 2 O 2 + 2NaOH
2H 2 O 2 \u003d 2H 2 O + O 2 |
Multicolored flame.Various flame colors can be shown when chlorides are burned in alcohol. To do this, take clean porcelain cups with 2-3 ml of alcohol. 0.2-0.5 g of finely ground chlorides are added to the alcohol. The mixture is ignited. In each cup, the color of the flame is characteristic of the cation that is present in the salt: lithium - raspberry, sodium - yellow, potassium - violet, rubidium and cesium - pink-violet, calcium - brick red, barium - yellowish green, strontium - raspberry, etc.
Magic wands.Three chemical beakers are filled with solutions of litmus, methyl orange and phenolphthalein to about 3/4 of the volume.
Solutions are prepared in other glasses hydrochloric acid s and sodium hydroxide. Sodium hydroxide solution is collected with a glass tube. Stir the liquid in all the glasses with this tube, imperceptibly pouring out a small amount of the solution each time. The color of the liquid in the glasses will change. Then acid is collected in this way into the second tubeand mix liquids in glasses with it. The color of the indicators will again change dramatically.
Magic wand.For the experiment, a pre-prepared slurry of potassium permanganate and concentrated sulfuric acid is placed in porcelain cups. The glass rod is immersed in the freshly prepared oxidizing mixture. Quickly bring the stick to the damp wick of a spirit lamp or cotton wool soaked in alcohol, the wick ignites. (It is forbidden to bring a stick re-moistened with alcohol into the gruel.)
2KMnO 4 + H 2 SO 4 \u003d Mn 2 O 7 + K 2 SO 4 + H 2 O
6Mp 2 O 7 + 5C 2 H 5 OH + 12H 2 SO 4 \u003d l2MnSO 4 + 10CO 2 + 27H 2 O
The reaction takes place with the release of a large amount of heat, the alcohol ignites.
Self-igniting liquid.0.5 g of potassium permanganate crystals slightly ground in a mortar are placed in a porcelain cup, and then 3-4 drops of glycerin are applied from a pipette. After a while, the glycerin ignites:
14KMnO 4 + 3C 3 H 6 (OH) 3 \u003d 14MnO 2 + 9CO 2 + 5H 2 O + 14KOH
Combustion of various substancesin molten crystals.
Three tubes are 1/3 filled with white crystals of potassium nitrate. All three test tubes are fixed vertically in a rack and simultaneously heated with three spirit lamps. When the crystals melt,a piece of heated charcoal is lowered into the first test tube, a piece of heated sulfur into the second, and a little lit red phosphorus into the third. In the first test tube, the coal burns, "jumping" at the same time. In the second test tube, a piece of sulfur burns with a bright flame. In the third test tube, red phosphorus burns out, releasing such an amount of heat that the test tube melts.
Water is a catalyst.Mix gently on a glass plate
4 g of powdered iodine and 2 g of zinc dust. The reaction does not occur. A few drops of water are added to the mixture. An exothermic reaction begins with the release of a violet vapor of iodine, which reacts with zinc. The experiment is carried out under tension.
Self-ignition of paraffin.Fill 1/3 of the tubes with pieces of paraffin and heat to its boiling point. Boiling paraffin is poured from a test tube, from a height of about 20 cm, in a thin stream. Paraffin flares up and burns with a bright flame. (In a test tube, paraffin cannot ignite, since there is no air circulation. When paraffin is poured out in a thin stream, air access to it is facilitated. And since the temperature of the molten paraffin is higher than its ignition temperature, it flares up.)
Municipal Autonomous General Educational Institution
Medium comprehensive school № 35
town Novomikhailovsky
municipality
Tuapse district
Entertaining experiences on the subject
"Chemistry in our house"
Teacher:
Kozlenko
Alevtina Viktorovna
2015
Smoke without fire. A few drops of concentrated hydrochloric acid are poured into one cleanly washed cylinder, and an ammonia solution is poured into the other. Both cylinders are closed with lids and placed at some distance from each other. Before the experiment show that the cylinders let. During the demonstration, the hydrochloric acid cylinder (on the walls) is turned upside down and placed on the cap of the ammonia cylinder. The lid is removed: white smoke is formed.
Golden Knife. To 200 ml of a saturated solution of copper sulphate, add 1 ml of sulfuric acid. Take a knife cleaned with sandpaper. Dip the knife for a few seconds in a solution of copper sulfate, take it out, rinse it and immediately wipe it dry with a towel. The knife becomes golden. It was covered with an even, shiny layer of copper.
Freezing glass.Ammonium nitrate is poured into a glass of water and placed on wet plywood, which freezes to the glass.
Color solutions. Crystal hydrates of copper, nickel, and cobalt salts are dehydrated before the experiment. After adding water to them, colored solutions are formed. Anhydrous white copper salt powder forms a solution blue color, green nickel-green salt powder, blue salt powder 4 cobalt red.
Blood without a wound. For the experiment, use 100 ml of a 3% solution of ferric chloride FeCI 3 in 100 ml of a 3% solution of potassium thiocyanate KCNS. To demonstrate the experience, a children's polyethylene sword is used. Call someone from the audience to the stage. Wash the palm with a cotton swab with a solution of FeCI 3 , and the sword is moistened with a colorless solution of KCNS. Next, the sword is drawn across the palm: “blood” flows abundantly on the paper:
FeCl 3 + 3KCNS \u003d Fe (CNS) 3 + 3KCl
"Blood" from the palm is washed off with cotton wool moistened with a solution of sodium fluoride. They show the audience that there is no wound and the palm is completely clean.
Instant color "photo".Yellow and red blood salts, interacting with salts of heavy metals, give various colors reaction products: yellow blood salt with iron (III) sulfate gives a blue color, with copper (II) salts - dark brown, with bismuth salts - yellow, with iron (II) salts - green. The above salt solutions on white paper make a drawing and dry it. Since the solutions are colorless, the paper remains uncolored. For the development of such drawings, a wet swab moistened with a solution of yellow blood salt is carried out on paper.
The transformation of liquid into jelly.Pour 100 g of sodium silicate solution into a beaker and add 5 ml of 24% hydrochloric acid solution. Stir the mixture of these solutions with a glass rod and hold the rod vertically in the solution. After 1-2 minutes, the rod no longer falls in the solution, because the liquid has thickened so that it does not pour out of the glass.
Chemical vacuum in a flask. Fill the flask carbon dioxide. Pour a little concentrated solution of potassium hydroxide into it and close the opening of the bottle with a peeled hard-boiled egg, the surface of which is smeared with a thin layer of petroleum jelly. The egg gradually begins to be drawn into the bottle and, with a sharp sound of a shot, falls on her bottom.
(A vacuum was formed in the flask as a result of the reaction:
CO 2 + 2KOH \u003d K 2 CO 3 + H 2 O.
Outside air pressure pushes the egg.)
Fireproof handkerchief.The handkerchief is impregnated with a solution of sodium silicate, dried and folded. To demonstrate incombustibility, it is moistened with alcohol and set on fire. The handkerchief should be kept straightened with crucible tongs. The alcohol burns off, and the fabric impregnated with sodium silicate remains unharmed.
Sugar is on fire.Take a piece of refined sugar with tongs and try to set it on fire - the sugar does not light up. If this piece is sprinkled with cigarette ashes, and then set on fire with a match, the sugar lights up with a bright blue flame and quickly burns out.
(The ashes contain lithium compounds that act as a catalyst.)
Charcoal from sugar. Weigh 30 g powdered sugar and transfer it to a beaker. Pour ~ 12 ml of concentrated sulfuric acid into powdered sugar. Mix sugar and acid with a glass rod into a mushy mass. After a while, the mixture turns black and heats up, and soon a porous coal mass begins to crawl out of the glass.
Municipal Autonomous General Educational Institution
Secondary school No. 35
town Novomikhailovsky
municipality
Tuapse district
Entertaining experiences on the subject
"Chemistry in Nature"
Teacher:
Kozlenko
Alevtina Viktorovna
2015
Extraction of "gold".In one flask with hot water dissolve lead acetate, and in the other - potassium iodide. Both solutions are poured into a large flask, the mixture is allowed to cool and show beautiful golden scales floating in the solution.
Pb (CH 3 COO) 2 + 2KI \u003d PbI 2 + 2CH3COOK
Mineral "chameleon".3 ml of a saturated potassium permanganate solution and 1 ml of a 10% potassium hydroxide solution are poured into a test tube.
10-15 drops of sodium sulfite solution are added to the resulting mixture while shaking until a dark green color appears. When stirred, the color of the solution turns blue, then purple and finally raspberry.
The appearance of a dark green color is due to the formation of potassium manganate
K 2 MPO 4:
2KMpo 4 + 2KOH + Na 2 SO 3 \u003d 2K 2 MnO 4 + Na 2 SO 4 + H 2 O.
The change in the dark green color of the solution is due to the decomposition of potassium manganate under the influence of atmospheric oxygen:
4K 2 MnO 4 + O 2 + 2H 2 O \u003d 4KMpO 4 + 4KON.
The transformation of red phosphorus into white.A glass rod is lowered into a dry test tube and red phosphorus is placed in the amount of half a pea. The bottom of the test tube is very hot. First, there is white smoke. With further heating, yellowish droplets of white phosphorus appear on the cold inner walls of the test tube. It is also deposited on a glass rod. After stopping the heating of the test tube, the glass rod is removed. White phosphorus ignites on it. With the end of a glass rod, white phosphorus is also removed from the inner walls of the test tube. In the air there is a second flash.
The experiment is carried out only by the teacher.
Pharaoh snakes. For the experiment, a salt is prepared - mercury (II) thiocyanate by mixing a concentrated solution of mercury (II) nitrate with a 10% solution of potassium thiocyanate. The precipitate is filtered, washed with water and sticks are made 3-5 mm thick and 4 cm long. The sticks are dried on glass at room temperature. During the demonstration, sticks are placed on a demonstration table and set on fire. As a result of the decomposition of mercury (II) thiocyanate, products are released that take the form of a writhing snake. Its volume is many times greater than the original volume of salt:
Hg (NO 3) 2 + 2KCNS \u003d Hg (CNS) 2 + 2KNO 3
2Hg (CNS| 2 = 2HgS + CS 2 + C 3 N 4 .
Dark gray snake.Sand is poured into a crystallizer or onto a glass plate and impregnated with alcohol. A hole is made in the center of the cone and a mixture of 2 g of baking soda and 13 g of powdered sugar is placed there. Burn alcohol. Caxap turns into caramel, and soda decomposes with the release of carbon monoxide (IV). A thick dark gray "snake" crawls out of the sand. The longer the alcohol burns, the longer the "snake".
"Chemical algae». A solution of silicate glue (sodium silicate) diluted with an equal volume of water is poured into a glass. Crystals of calcium chloride, manganese (II), cobalt (II), nickel (II) and other metals are thrown to the bottom of the glass. After some time, crystals of the corresponding sparingly soluble silicates begin to grow in the glass, resembling algae.
Burning snow. Together with snow, 1-2 pieces of calcium carbide are placed in a jar. After that, a burning splinter is brought to the jar. The snow flares up and burns with a smoky flame. The reaction takes place between calcium carbide and water:
CaC 2 + 2H 2 O \u003d Ca (OH) 2 + C 2 H 2
The escaping gas - acetylene burns:
2C 2 H 2 + 5O 2 \u003d 4CO 2 + 2H 2 O.
"Buran" in a glass.Pour 5 g of benzoic acid into a 500 ml beaker and put a sprig of pine. Close the glass with a porcelain cup cold water and heated over an alcohol lamp. The acid first melts, then turns into steam, and the glass is filled with white "snow" that covers the twig.
Secondary school No. 35
Novomikhailovsky settlement
municipality
Tuapse district
Entertaining experiences on the subject
"Chemistry in Agriculture"
Teacher:
Kozlenko
Alevtina Viktorovna
2015
Different ways to get "milk".Solutions are prepared for the experiment: sodium chloride and silver nitrate; barium chloride and sodium sulfate; calcium chloride and sodium carbonate. Pour these solutions into separate beakers. In each of them, “milk” is formed - insoluble white salts:
NaCI + AgNO 3 \u003d AgCI ↓ + NaNO 3;
Na 2 SO 4 + ВаСI 2 \u003d BaSO 4 ↓ + 2NaCI;
Na 2 CO 3 + CaCI 2 \u003d CaCO 3 ↓ + 2NaCI.
Turning milk into water.An excess of hydrochloric acid is added to a white precipitate obtained by pouring solutions of calcium chloride and sodium carbonate. The liquid boils and becomes colorless and
transparent:
CaCl 2 + Na 2 CO 3 \u003d CaCO 3 ↓ + 2NaCl;
CaCO3↓ + 2HCI = CaCI 2 + H 2 O + CO 2.
original egg. An egg is dipped into a glass jar with a dilute solution of hydrochloric acid. After 2-3 minutes, the egg is covered with gas bubbles and floats to the surface of the liquid. The gas bubbles break off and the egg sinks to the bottom again. So, diving and rising, the egg moves until the shell dissolves.
Municipal educational institution
Secondary school No. 35
Novomikhailovsky settlement
municipality
Tuapse district
extracurricular activity
"Interesting questions about chemistry"
Teacher:
Kozlenko
Alevtina Viktorovna
2015
Quiz.
1. Name the ten most common in earth's crust elements.
2. What chemical element was discovered earlier on the Sun than on Earth?
3. What rare metal is included in some precious stones?
4. What is helium air?
5. What metals and alloys melt in hot water?
6. What refractory metals do you know?
7. What is heavy water?
8. Name the elements that make up the human body.
9. Name the heaviest gas, liquid and solid.
10. How many elements are used in the manufacture of a car?
11. What chemical elements enter the plant from air, water, soil?
12. What salts of sulfuric and hydrochloric acids are used to protect plants from pests and diseases?
13. What kind of molten metal can freeze water /?
14. Is drinking clean water good for a person?
15. Who was the first to determine the quantitative chemical composition water?
16 . What gas is in the solid state at a temperature - 2>252 °C combines with an explosion with liquid hydrogen?
17. What element is the basis of the entire mineral world of the Nanki planet?
18. Which compound of chlorine and mercury is a strong poison?
19. The names of what elements are associated with radioactive processes?
Answers:
1. The following elements are most common in the earth's crust: oxygen, silicon, aluminum, iron, calcium, sodium, magnesium, potassium, hydrogen, titanium. These elements occupy approximately 96.4% of the mass of the earth's crust; for all other elements, only 3.5% of the mass of the earth's crust remains.
2. Helium was first discovered on the Sun, and only a quarter of a century later it was found on Earth.
3. The metal beryllium is found in nature as component precious stones (beryl, aquamarine, alexandrite, etc.).
4. This is the name of artificial air, which includes approximately 20% oxygen and 80% helium.
5. The following metals melt in hot water: cesium (+28.5 °С), gallium (+ 29.75 °С), rubidium (+ 39 °С), potassium (+63 °С). Wood's alloy (50% Bi, 25% Pb, 12.5% Sn, 12.5% Cd) melts at +60.5°C.
6. The most refractory metals such as: tungsten (3370 ° C), rhenium (3160 ° C), tantalum (3000 ° C), osmium (2700 ° C), molybdenum (2620 ° C), niobium (2415 ° C).
7. Heavy water is the compound of the hydrogen isotope of deuterium with oxygen D 2 A. There is a small amount of heavy water in ordinary water (1 part by weight in 5000 parts by weight).
8. The composition of the human body includes more than 20 elements: oxygen (65.04%), carbon (18.25%), hydrogen (10.05%), nitrogen (2.65%), calcium (1.4%) , phosphorus (0.84%), potassium (0.27%), chlorine (0.21%), sulfur (0.21%) and
others
9. The heaviest gas taken under normal conditions is tungsten hexafluoride WF 6 , the heaviest liquid is mercury, the heaviest solid is osmium metal Os.
10. Approximately 50 chemical elements are used in the manufacture of a car, which are part of 250 different substances and materials.
11. Carbon, nitrogen, oxygen enter the plant from the air. Hydrogen and oxygen from water. All other elements enter the plant from the soil.
12. Copper and iron sulfates, barium and zinc chlorides are used to protect plants from pests and diseases.
13. You can freeze water with mercury, it melts at a temperature of 39 ° C.
14. Chemists consider distilled water to be relatively pure water. But it is harmful to the body, becauseit does not contain useful salts and gases. It flushes out the salts contained in the cell sap from the cells of the stomach.
15. The quantitative chemical composition of water, first by the method of synthesis, and then by analysis, was determined by Lavoisier.
16. Fluorine is a very strong oxidizing agent. In the solid state, it combines with liquid hydrogen at a temperature of -252 °C.
17. Silicon makes up 27.6% of the earth's crust and is the main element in the kingdom of minerals and rocks, which are exclusively composed of silicon compounds.
18. A strong poison is the combination of chlorine with mercury - sublimate. In medicine, sublimate is used as a disinfectant (1:1000).
19. The names of such elements are associated with radioactive processes: astatine, radium, radon, actinium, protactinium.
Do you know that...
For the production of 1 t building bricks 1-2 m required 3 water, and for the production of 1 t nitrogen fertilizers and 1 ton of capron - respectively 600, 2500 m 3 .
The layer of the atmosphere at an altitude of 10 to 50 km is called the ozonosphere. The total amount of ozone gas is small; at normal pressure and a temperature of 0 ° C, it would be distributed over earth's surface thin layer 2-3 mm. Ozone upper layers atmosphere absorbs most of the ultraviolet radiation that the Sun sends, and protects all living things from its harmful effects.
Polycarbonate is a polymer interesting features. It can be hard like metal, elastic like silk, transparent like crystal, or dyed different colors. The polymer can be molded. It does not burn, retains its properties at temperatures from +135 to -150 °C.
Ozone is toxic. In low concentrations (during a thunderstorm), the smell of ozone is pleasant and refreshing. At a concentration in the air of more than 1%, its smell is extremely unpleasant and it is impossible to breathe it.
A salt crystal with slow crystallization can reach a size of more than half a meter.
Pure iron is found on Earth only in the form of meteorites.
Burning magnesium cannot be extinguished with carbon dioxide, as it interacts with it and continues to burn due to the released oxygen.
The most refractory metal is tungsten (t pl 3410 ° C), and the most fusible metal is cesium (t pl 28.5 °С).
The largest gold nugget found in the Urals in 1837 weighed about 37 kg. A gold nugget of 108 kg was found in California, and 250 kg in Australia.
Beryllium is called the metal of indefatigability, because the springs made from its alloy can withstand up to 20 billion load cycles (they are almost eternal).
CURIOUS FIGURES AND FACTS
Freon substitutes. Freons and other synthetic substances containing chlorine and fluorine are known to destroy the ozone layer of the atmosphere. Soviet scientists found a replacement for freon - hydrocarbon propylanes (compounds of propane and butane), harmless to the atmospheric layer. By 1995, the chemical industry will produce 1 billion aerosols.
TU-104 and plastics. The TU-104 aircraft has 120,000 parts made of organic glass, other plastics and various combinations them with other materials.
Nitrogen and lightning. About 100 lightning strikes every second are one of the sources of nitrogen compounds. In this case, the following processes take place:
N 2 + O 2 \u003d 2NO
2NO+O 2 \u003d 2NO 2
2NO 2 + H 2 O + 1 / 2O 2 \u003d 2HNO 3
Thus, nitrate ions enter the soil, which are absorbed by plants.
Methane and warming. The methane content in the lower layers of the atmosphere (troposphere) averaged 0.0152 ppm 10 years ago. and was relatively constant. AT recent times there is a systematic increase in its concentration. An increase in the methane content in the troposphere contributes to an increase in the greenhouse effect, since methane molecules absorb infrared radiation.
Ashes in sea water. In the water of the seas and oceans there are dissolved salts of gold. Calculations show that the water of all seas and oceans contains about 8 billion tons of gold. Scientists are looking for the most profitable ways mining gold from sea water. 1 ton of sea water contains 0.01-0.05 mg of gold.
"White Soot" . In addition to the usual, well-known black soot, there is also “white soot”. Hak is a powder of amorphous silicon dioxide, which is used as a filler for rubber in the manufacture of rubber from it.
Threat from trace elements. The active circulation of trace elements accumulating in natural environments creates, according to experts, a serious threat to the health of modern man and future generations. Their sources are millions of tons of annually burned fuel, blast furnace production, non-ferrous metallurgy, introduced into the soil mineral fertilizers etc.
Transparent rubber.In the manufacture of rubber from rubber, zinc oxide is used (it speeds up the vulcanization process of rubber). If zinc peroxide is added to rubber instead of zinc oxide, then the rubber is transparent. Through a layer of such rubber 2 cm thick, you can freely read a book.
Oil is more precious than gold.Rose oil is required to make many types of perfume. It is a mixture of aromatic substances extracted from rose petals. To obtain 1 kg of this oil, 4-5 tons of petals must be collected and subjected to chemical treatment. Rose oil is filtered three times more expensive than gold.
Iron is within us.The body of an adult contains 3.5 g of iron. This is very little compared, for example, with calcium, which is more than 1 kg in the body. But if we compare not the total content of these elements, but their concentration only in the blood, then there is five times more iron than calcium. The main mass of iron, which is part of the body (2.45 g), is concentrated in blood erythrocytes. Iron is found in the muscle protein myoglobin and in many enzymes. 1% of iron constantly circulates in plasma - the liquid part of the blood. The main "depot" of iron is the liver: here, an adult male can store up to 1 g of iron. Between all tissues and organs containing iron, there is a constant exchange. About 10% of iron is brought into the bone marrow by the blood. It is part of the pigment that colors the hair.
Phosphorus - the element of life and thought. In animals, phosphorus is concentrated mainly in the skeleton, muscles and nervous tissue. The human body contains on average about 1.5 kg of phosphorus. Of this mass, 1.4 kg is in the bones, about 130 g is in the muscles, and 12 g is in the nerves and brain. Almost all physiological processes occurring in our body are associated with the transformation of organophosphorus substances.
asphalt lake. On the island of Trinidad in the Lesser Antilles group, there is a lake filled not with water, but with frozen asphalt. Its area is 45 hectares, and the depth reaches 90 m. It is believed that the lake was formed in the crater of a volcano, into which oil penetrated through underground cracks. Millions of tons of asphalt have already been extracted from it.
Microalloying.Microalloying is one of the central problems of modern materials science. By introducing small amounts (approximately 0.01%) of certain elements, it is possible to noticeably change the properties of the alloys. This is due to segregation, i.e., the formation of an excess concentration of alloying elements on structural defects.
Types of coal. "Colorless Coal"- this is gas, "yellow coal" - solar energy, "green coal" - vegetable fuel, "blue coal" - the energy of the ebbs and flows of the seas, "blue coal" - the driving force of the wind, "red coal" - the energy of volcanoes.
Native aluminium.Recent discoveries of native metallic aluminum have raised the question of how it was formed. According to scientists, in natural melts under the influence of electrotelluric currents (electric currents flowing in the earth's crust), aluminum is reduced electrochemically.
Plastic nail.Plastic masses - polycarbonates were also suitable for the manufacture of nails. Nails from them are freely driven into the board and do notrust, in many cases perfectly replacing iron nails.
Sulfuric acid in nature. Sulfuric acid is obtained fromchemical plants. It turned out that it is formed in nature, primarily in volcanoes. For example, in the waters of the Rio Negro, which originates from the Puracho volcano in South America, in the crater of which sulfur is formed, contains up to0.1% sulfuric acid. The river daily carries into the sea up to 20 liters of "volcanic" sulfuric acid. In the USSR, sulfuric acid was discovered by academician Fersman in sulfur deposits in the Karakum desert.
Fun chemistry games
Who is faster and more?The teacher invites the participants of the game to write the names of the elements ending in the same letter, for example, in “n” (argon, krypton, xenon, lanthanum, molybdenum, neon, radon, etc.). The game can be made more difficult by offering to find these elements in the table
D. I. Mendeleev and indicate which of them are metals and which non-metals.
Make up the names of the elements.The teacher calls the student to the blackboard and asks him to write down a series of syllables. The rest of the students write them in their notebooks. Task: in 3 minutes, make possible names of elements from the recorded syllables. For example, from the syllables "se, tiy, diy, ra, lion, li" you can compose the words: "lithium, sulfur, radium, selenium."
Drawing up reaction equations.“Who can quickly write equations for reactions, for example, between a metal and oxygen? - asks the teacher, referring to the participants in the game. - Write down the equation for the oxidation of aluminum. Whoever writes the equation first, let him raise his hand.”
Who knows more?The teacher closes the table with a strip of paper
D. I. Mendeleev some group of elements (or period) and in turn invites the teams to name and write the signs of the elements of a closed group (or period). The winner is the student who names the most chemical elements and correctly writes their signs.
The meaning of the names of elements in translation from a foreign language.What does the word "bromine" mean in Greek? You can play the same game and find out by the participants the meaning of the names of the elements translated from Latin (for example, ruthenium, tellurium, gallium, hafnium, lutetium, holmium, etc.).
Name the formula. The teacher names some compound, for example, magnesium hydroxide. The players, in whose hands are tablets with formulas, run out, holding a tablet with the corresponding formula in their hands.
Charades, puzzles,
chainwords, crosswords.
1 . The first four letters of the name of the famous Greek philosopher "denote the word" people "in Greek without the last letter, the last four are an island in the Mediterranean Sea; in general - the name of the Greek philosopher, founder of the atomistic theory.(Demos, Crete - Democritus.)
2. The first syllable of the name of a chemical element is also the first of the name of one of the elements of the platinum group; in general, it is the metal for which Marie Skłodowska-Curie won the Nobel Prize.(Radon, rhodium - radium.)
3. The first syllable of the name of the chemical element is also the first of the name of the "lunar element"; the second is the first in the name of the metal discovered by M. Sklodowska-Curie; in general it is (in alchemical language) "the gall of the god Vulcan".(Selenium, radium - sulfur.)
4. The first syllable of the name is also the first syllable of the name of an asphyxiant gas obtained by the synthesis of carbon monoxide (II) and chlorine; the second syllable is the first in the name of the solution of formaldehyde in water; in general, it is a chemical element, about which A.E. Fersman wrote that it is an element of life and thought.(Phosgene, formalin- phosphorus.)
Helpful Hints
Children are always trying to find out something new every day and they always have a lot of questions.
They can explain some phenomena, or you can show how this or that thing, this or that phenomenon works.
In these experiments, children not only learn something new, but also learn create differentcrafts with which they can play further.
1. Experiments for children: lemon volcano
You will need:
2 lemons (for 1 volcano)
Baking soda
Food coloring or watercolors
Dishwashing liquid
Wooden stick or spoon (optional)
1. Cut off the bottom of the lemon so that it can be placed on flat surface.
2. On the reverse side, cut a piece of lemon as shown in the image.
* You can cut half a lemon and make an open volcano.
3. Take the second lemon, cut it in half and squeeze the juice out of it into a cup. This will be the backup lemon juice.
4. Place the first lemon (with the part cut out) on the tray and spoon "remember" the lemon inside to squeeze out some of the juice. It is important that the juice is inside the lemon.
5. Add food coloring or watercolor to the inside of the lemon, but do not stir.
6. Pour dishwashing liquid inside the lemon.
7. Add a full tablespoon of baking soda to the lemon. The reaction will start. With a stick or spoon, you can stir everything inside the lemon - the volcano will begin to foam.
8. To make the reaction last longer, you can gradually add more soda, dyes, soap and reserve lemon juice.
2. Home experiments for children: electric eels from chewing worms
You will need:
2 glasses
small capacity
4-6 chewable worms
3 tablespoons of baking soda
1/2 spoon of vinegar
1 cup water
Scissors, kitchen or clerical knife.
1. With scissors or a knife, cut lengthwise (just lengthwise - this will not be easy, but be patient) of each worm into 4 (or more) parts.
* The smaller the piece, the better.
* If scissors don't want to cut properly, try washing them with soap and water.
2. Mix water and baking soda in a glass.
3. Add pieces of worms to the solution of water and soda and stir.
4. Leave the worms in the solution for 10-15 minutes.
5. Using a fork, transfer the worm pieces to a small plate.
6. Pour half a spoon of vinegar into an empty glass and start putting worms in it one by one.
* The experiment can be repeated if the worms are washed with plain water. After a few attempts, your worms will begin to dissolve, and then you will have to cut a new batch.
3. Experiments and experiments: a rainbow on paper or how light is reflected on a flat surface
You will need:
bowl of water
Clear nail polish
Small pieces of black paper.
1. Add 1-2 drops to a bowl of water clear varnish for nails. See how the varnish disperses through the water.
2. Quickly (after 10 seconds) dip a piece of black paper into the bowl. Take it out and let it dry on a paper towel.
3. After the paper has dried (it happens quickly) start turning the paper and look at the rainbow that is displayed on it.
* To better see the rainbow on paper, look at it under the sun's rays.
4. Experiments at home: a rain cloud in a jar
When small drops of water accumulate in a cloud, they become heavier and heavier. As a result, they will reach such a weight that they can no longer remain in the air and will begin to fall to the ground - this is how rain appears.
This phenomenon can be shown to children with simple materials.
You will need:
Shaving foam
Food coloring.
1. Fill the jar with water.
2. Apply shaving foam on top - it will be a cloud.
3. Let the child begin to drip food coloring onto the "cloud" until it starts to "rain" - drops of food coloring begin to fall to the bottom of the jar.
During the experiment, explain this phenomenon to the child.
You will need:
warm water
Sunflower oil
4 food coloring
1. Fill the jar 3/4 full with warm water.
2. Take a bowl and mix 3-4 tablespoons of oil and a few drops of food coloring in it. In this example, 1 drop of each of 4 dyes was used - red, yellow, blue and green.
3. Stir the dyes and oil with a fork.
4. Carefully pour the mixture into a jar of warm water.
5. Watch what happens - the food coloring will begin to slowly sink through the oil into the water, after which each drop will begin to disperse and mix with other drops.
* Food coloring dissolves in water, but not in oil, because. The density of oil is less than water (which is why it "floats" on water). A drop of dye is heavier than oil, so it will begin to sink until it reaches the water, where it begins to disperse and look like a small firework.
6. Interesting experiences: ina bowl in which colors merge
You will need:
- a printout of the wheel (or you can cut out your own wheel and draw all the colors of the rainbow on it)
Elastic band or thick thread
Glue stick
Scissors
A skewer or screwdriver (to make holes in the paper wheel).
1. Choose and print the two templates you want to use.
2. Take a piece of cardboard and use a glue stick to glue one template to the cardboard.
3. Cut out the glued circle from the cardboard.
4. Glue the second template to the back of the cardboard circle.
5. Use a skewer or screwdriver to make two holes in the circle.
6. Pass the thread through the holes and tie the ends into a knot.
Now you can spin your spinning top and watch how the colors merge on the circles.
7. Experiments for children at home: jellyfish in a jar
You will need:
Small transparent plastic bag
Transparent plastic bottle
Food coloring
Scissors.
1. Lay the plastic bag on a flat surface and smooth it out.
2. Cut off the bottom and handles of the bag.
3. Cut the bag lengthwise on the right and left so that you have two sheets of polyethylene. You will need one sheet.
4. Find a center polyethylene sheet and fold it like a balloon to make a jellyfish head. Tie the thread around the "neck" of the jellyfish, but not too tight - you need to leave a small hole through which to pour water into the head of the jellyfish.
5. There is a head, now let's move on to the tentacles. Make cuts in the sheet - from the bottom to the head. You need about 8-10 tentacles.
6. Cut each tentacle into 3-4 smaller pieces.
7. Pour some water into the jellyfish's head, leaving room for air so the jellyfish can "float" in the bottle.
8. Fill the bottle with water and put your jellyfish in it.
9. Drop a couple of drops of blue or green food coloring.
* Close the lid tightly so that water does not spill out.
* Have the children turn the bottle over and watch the jellyfish swim in it.
8. Chemical experiments: magic crystals in a glass
You will need:
Glass cup or bowl
plastic bowl
1 cup Epsom salt (magnesium sulfate) - used in bath salts
1 cup hot water
Food coloring.
1. Pour Epsom salt into a bowl and add hot water. You can add a couple of drops of food coloring to the bowl.
2. Stir the contents of the bowl for 1-2 minutes. Most of the salt granules should dissolve.
3. Pour the solution into a glass or glass and place it in the freezer for 10-15 minutes. Don't worry, the solution isn't hot enough to crack the glass.
4. After freezing, move the solution to the main compartment of the refrigerator, preferably on top shelf and leave overnight.
The growth of crystals will be noticeable only after a few hours, but it is better to wait out the night.
This is what the crystals look like the next day. Remember that crystals are very fragile. If you touch them, they are most likely to break or crumble immediately.
9. Experiments for children (video): soap cube
10. Chemical experiments for children (video): how to make a lava lamp with your own hands
