Evening of entertaining chemistry
When preparing a chemistry evening, careful preparation of the teacher for conducting experiments is required.
The evening should be preceded by long, thorough work with students, and one student should not be assigned more than two experiments.
The purpose of the chemistry evening– repeat acquired knowledge, deepen students’ interest in chemistry and instill in them practical skills in developing and implementing experiments.
Description of the main stages of an evening of entertaining chemistry
I. Introductory speech by the teacher on the topic “The role of chemistry in the life of society.”
II. Entertaining experiments in chemistry.
Presenter (the role of the presenter is played by one of the 10-11th grade students):
Today we are having an evening of entertaining chemistry. Your task is to carefully monitor chemical experiments and try to explain them. And so, we begin! Experiment No. 1: “Volcano”.
Experiment No. 1. Description:
A participant in the evening pours powdered ammonium dichromate (in the form of a slide) onto an asbestos mesh, onto top part Gorki puts a few heads of matches and lights them with a splinter.
Note: the volcano will look even more impressive if you add a little powdered magnesium to the ammonium dichromate. Mix the components of the mixture immediately, because magnesium burns energetically and, being in one place, causes the scattering of hot particles.
The essence of the experiment is the exothermic decomposition of ammonium dichromate upon local heating.
There is no smoke without fire - says an old Russian proverb. It turns out that with the help of chemistry you can create smoke without fire. And so, attention!
Experiment No. 2. Description:
The participant of the evening takes two glass rods, on which a little cotton wool is wound, and moistens them: one in concentrated nitric (or hydrochloric) acid, the other in an aqueous 25% ammonia solution. The sticks should be brought close to each other. White smoke rises from the sticks.
The essence of the experiment is the formation of ammonium nitrate (chloride).
And now we present to you the following experiment – “Shooting paper”.
Experiment No. 3. Description:
The party participant takes out pieces of paper on a sheet of plywood and touches them with a glass rod. When you touch each leaf, a shot is heard.
Note: narrow strips of filter paper are cut in advance and moistened in an iodine solution in ammonia. After this, the strips are laid out on a sheet of plywood and left to dry until the evening. The stronger the shot is, the better the paper is soaked in the solution and the more concentrated the nitrogen iodide solution is.
The essence of the experiment is the exothermic decomposition of the fragile compound NI3*NH3.
I have an egg. Which one of you guys can peel it without breaking the shell?
Experiment No. 4. Description:
The party participant places the egg in a crystallizer with a solution of hydrochloric (or acetic) acid. After some time, he pulls out an egg covered only with the shell membrane.
The essence of the experiment is that the shell mainly contains calcium carbonate. In hydrochloric (acetic) acid it turns into soluble calcium chloride (calcium acetate).
Guys, I have in my hands a figurine of a man made of zinc. Let's dress him up.
Experiment No. 5. Description:
The participant of the evening lowers the figurine into a 10% solution of lead acetate. The figurine is covered with a fluffy layer of lead crystals, reminiscent of fur clothing.
The essence of the experiment is that a more active metal squeezes out a less active metal from salt solutions.
Guys, is it possible to burn sugar without the help of fire? Let's check!
Experiment No. 6. Description:
The participant of the evening pours into a glass placed on a saucer, powdered sugar(30 g), pour in 26 ml of concentrated sulfuric acid and stir the mixture with a glass rod. After 1-1.5 minutes, the mixture in the glass darkens, swells and rises above the edges of the glass in the form of a loose mass.
The essence of the experiment is that sulfuric acid removes water from sugar molecules, oxidizes carbon into carbon dioxide, and at the same time sulfur dioxide is formed. The released gases push the mass out of the glass.
What methods of making fire do you know?
Examples are given from the audience.
Let's try to do without these funds.
Experiment No. 7. Description:
A participant in the evening sprinkles powdered potassium permanganate (6 g) onto a piece of tin (or tile) and drops glycerin onto it from a pipette. After some time, fire appears.
The essence of the experiment is that as a result of the reaction, atomic oxygen is released and glycerin ignites.
Another participant of the evening:
I will also get fire without matches, just in a different way.
Experiment No. 8. Description:
The party participant sprinkles a small amount of potassium permanganate crystals on the brick and drops concentrated sulfuric acid onto it. Around this mixture he places thin wood chips in the form of a fire, but so that they do not touch the mixture. Then he moistens a small piece of cotton wool with alcohol and, holding his hand over the fire, squeezes out a few drops of alcohol from the cotton wool so that they fall on the mixture. The fire instantly lights up.
The essence of the experiment is that the alcohol is vigorously oxidized with oxygen, which is released during the interaction of sulfuric acid with potassium permanganate. The heat released during this reaction ignites the fire.
Now for the amazing lights!
Experiment No. 9. Description:
The party participant places cotton swabs soaked in ethyl alcohol into porcelain cups. He sprinkles the following salts on the surface of the tampons: sodium chloride, strontium nitrate (or lithium nitrate), potassium chloride, barium nitrate (or boric acid). On a piece of glass, the participant prepares a mixture (gruel) of potassium permanganate and concentrated sulfuric acid. He takes a little of this mass with a glass rod and touches the surface of the tampons. Tampons flare up and burn different colors: yellow, red, purple, green.
The essence of the experiment is that ions of alkali and alkaline earth metals color the flame in different colors.
Dear guys, I am so tired and hungry that I ask you to allow me to eat a little.
Experiment No. 10. Description:
The host addresses the evening participant:
Give me tea and crackers, please.
The participant in the evening gives the presenter a glass of tea and white crackers.
The presenter wets the cracker in tea - the cracker turns blue.
Leading :
It's a disgrace, you almost poisoned me!
Participant of the evening:
Forgive me, I probably got the glasses mixed up.
The essence of the experiment is that there was an iodine solution in the glass. The starch in the bread has turned blue.
Guys, I received a letter, but the envelope contained a blank sheet of paper. Who can help me find out what's going on here?
Experiment No. 11. Description:
A student from the audience (prepared in advance) touches a smoldering splinter to a pencil mark on a sheet of paper. The paper slowly burns along the line of the drawing and the light, moving along the contour of the image, outlines it (the drawing can be arbitrary).
The essence of the experiment is that the paper burns due to the oxygen of saltpeter crystallized in its thickness.
Note: a drawing is applied to a sheet of paper in advance with a strong solution of potassium nitrate. It must be applied in one continuous line without intersections. From the outline of the drawing, use the same solution to draw a line to the edge of the paper, marking its end with a pencil. When the paper dries, the design will become invisible.
Well, now, guys, let's move on to the second part of our evening. Chemistry games!
III. Team games.
Participants of the evening are asked to split into groups. Each group takes part in the game proposed to it.
Game number 1. Chemical lotto.
Formulas are written on the cards, lined up like in a regular lotto. chemical substances, and on cardboard squares are the names of these substances. Group members are given cards, and one of them pulls out squares and names the substances. The first group member to cover all the fields on the card wins.
Game number 2. Chemistry quiz.
A rope is stretched between the backs of two chairs. Candies are tied to it on strings, to which pieces of paper with questions are attached. The group members take turns cutting off the candies with scissors. The player becomes the owner of the candy after answering the question attached to it.
Group members form a circle. They hold chemical symbols and numbers in their hands. Two of the players are in the middle of the circle. On command, they create a chemical formula of substances from the signs and numbers held by the other players. The participant who completes the formula the fastest wins.
The group members are divided into two teams. They are given cards with chemical formulas and numbers. They must write a chemical equation. The team that completes the equation first wins.
The evening ends with the presentation of prizes to the most active participants.
Did you know that May 29 is Chemist's Day? Who among us in childhood did not dream of creating unique magic, amazing chemical experiments? It's time to make your dreams come true! Read on quickly and we will tell you how to have fun on Chemist Day 2017, as well as what chemical experiments for children can be easily done at home.
Home volcano
If you are not already attracted, then... Do you want to see a volcanic eruption? Try 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 baking soda into a plastic cup, add ¼ cup of warm water and a little food coloring, preferably red. Then add ¼ vinegar and watch the volcano “erupt”.
Rose and ammonia
A very interesting and original chemical experiment with plants can be seen in the video from YouTube:
Self-inflating balloon
Do you want to conduct safe chemical 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 a 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 a gas burner. Watch the algorithm of actions on YouTube video:
Colorful magic
Do you want to surprise your child? Hurry up and conduct chemical experiments with color! You will need the following available ingredients: starch, iodine, transparent container.
Mix snow-white starch and brown iodine in a container. The result is an amazing mixture of blue.
Raising a snake
The most interesting home chemical experiments can be carried out using available ingredients. To create a snake you will need: a plate, river sand, powdered sugar, ethyl alcohol, a lighter or burner, baking soda.
Place a pile of sand on a plate and soak it in alcohol. Make a depression in the top of the slide, where you carefully add powdered sugar and soda. Now we set fire to the sand slide and watch. After a couple of minutes, a dark wriggling ribbon that resembles a snake will begin to grow from the top of the slide.
How to conduct chemical experiments with an explosion, see the following video from Youtube:
"Pharaoh's Snakes"
origin of name
Nobody knows for sure the origin of the name “Pharaoh’s snakes”, but it is dated to biblical events. In order to impress Pharaoh, the prophet Moses, on the advice of the Lord, threw his staff on the ground, and it turned into a snake. Once in the hands of the chosen one, the reptile again became a staff. Although in fact there is nothing in common between how these experiences are obtained and biblical events.
What can you get "pharaoh snakes" from?
The most common substance used to produce snakes is mercury thiocyanate. However, experiments with it can only be carried out in a well-equipped chemical laboratory. The substance is toxic and has an unpleasant, persistent odor. And a “pharaoh’s snake” at home can be created from tablets that are sold in any pharmacy without a prescription, or mineral fertilizers from a hardware store.
To conduct the experiment, calcium gluconate, methenamine, soda, powdered sugar, saltpeter and many substances that can be purchased at a pharmacy or store are used. “Snakes” from tablets containing sulfonamides The easiest way to conduct the “Pharaoh’s snakes” experiment at home is from drugs of the sulfonamide group. These are products such as “Streptotsid”, “Biseptol”, “Sulfadimezin”, “Sulfadimethoxine” and others. Almost everyone has these drugs in their home. "Pharaoh's snakes" from sulfonamides turn out shiny gray, their structure resembles corn sticks. If you carefully grab the “head” of the snake with a clamp or tweezers, you can pull out a fairly long reptile from one tablet.
In order to conduct the Pharaoh's Snake chemical experiment, you will need a burner or dry fuel and the above-mentioned medications. Several tablets are laid out on dry alcohol, which is set on fire. During the reaction, substances such as nitrogen, sulfur dioxide, hydrogen sulfide and water vapor are released.
The reaction formula is as follows:
С11H12N4O2S+7O2 = 28C+2H2S+2SO2+8N2+18H2O
Such an experiment must be carried out very carefully, since sulfur dioxide is very toxic, just like hydrogen sulfide. Therefore, if it is not possible to ventilate the room during the experiment or turn on the hood, it is better to do this outside or in a specially equipped laboratory. “Snakes” from calcium gluconate It is best to conduct experiments using substances that are safe, even if used outside a specially equipped laboratory.
"Pharaoh's snake" from calcium gluconate is obtained quite simply. This will require 2-3 tablets medicinal product and a cube of dry fuel. Under the influence of the flame, a reaction begins, and a gray “snake” crawls out of the tablet. Such experiments with calcium gluconate are quite safe, but you should still be careful when conducting them. The formula for the chemical reaction is as follows:
C12H22CaO14+O2 = 10C+2CO2+CaO+11H2O
As we can see, a reaction occurs with the release of water, carbon dioxide, carbon and calcium oxide. It is the release of gas that causes growth. "Pharaoh's snakes" are up to 15 centimeters long, but they are short-lived. When you try to pick them up, they fall apart.
"Pharaoh's snake" - how to make it from fertilizer?
If you have a vegetable garden personal plot or a dacha, then there are certainly various fertilizers. The most common one, which can be found in the pantry of any summer resident and farmer, is ammonium nitrate or ammonium nitrate. For the experiment you will need sifted river sand, half a teaspoon of saltpeter, half a teaspoon of powdered sugar, and a spoon of ethyl alcohol. It is necessary to make a depression in the sand slide. The larger the diameter, the thicker the “snake” will be. A well-ground mixture of saltpeter and sugar is poured into the recess and filled with ethyl alcohol. Then the alcohol is set on fire, and a “snake” is gradually formed. The reaction then occurs as follows:
2NH4NO3 + C12H22O11 = 11C + 2N2 + CO2 + 15H2O.IN
The release of toxic substances during the experiment requires compliance with safety precautions.
"Pharaoh's snake" from food products
"Pharaoh's snakes" are obtained not only from medicines or fertilizers. For experience, you can use products such as sugar and soda. Such components can be found in any kitchen. From river sand a slide with a depression is formed and soaked in alcohol. Powdered sugar and baking soda are mixed in a 4:1 ratio and poured into the recess. The alcohol is set on fire. The mixture begins to turn black and slowly swell. When the alcohol almost stops burning, several wriggling “reptiles” crawl out of the sand. The reaction is as follows:
2NaHCO3 = Na2CO3 + H2O + CO2, C2H5OH + 3O2 = 2CO2 + 3H2O
The mixture decomposes into sodium carbonate, carbon dioxide and water vapor. It is the gases that cause soda ash to swell and grow, which does not burn during the reaction.
Ampicillin chameleon
Take an ampicillin tablet and crush it. Place the powder in a test tube, add 5 ml of distilled water to it and close with a stopper. Shake the resulting mixture for 12 minutes and then filter.
Pour 1 ml into a test tubereceivedampicillin solution and the same amount5-10 % solutionNaOH. Add 2 to the resulting mixture3 drops 10% solutionCuSO 4 . Shake the test tube. A violet color appears, characteristic of the biuret reaction. Gradually the color changes to brown.
Smoke without fire - 3
The experiment must be carried out in a well-ventilated area or in a fume hood.Take two beakers. Pour a few drops into one of them25 % solutionammonia,and in the other - a few dropsconcentrated hydrochloric acid( be careful!). Bring the glasses closer to each other.White smoke will be released.Thisis formedammonium chloride:
N.H. 3 +HClN.H. 4 Cl.
Bloody experience
For gettingbloodwe willuse the reaction between thiocyanate and iron salt(III), For example:
2FeCl 3 +6KSCNFe + 6KCl.
You can write a simplified version of the equation with the formation of a low-dissociation product:
FeCl 3 + 3 KSCNFe( SCN) 3 + 3 KCl
Fe 3+ + 3 SCN Fe( SCN) 3 .
Typically, potassium or ammonium thiocyanate and ferric chloride are used for the reaction (III). During its course, a blood-red autocomplex thiocyanate is formed.
For the experiment, you need to take glasses with solutions of potassium thiocyanate (ammonium) and ferric chloride (III), as well as two glass rods with cotton wool wrapped around them. Prepare a plastic or steel knife. It must be blunted, otherwise the experience can become really bloody.
Wipe your palm with an iron salt solution (viewers can be informed that this is disinfection with an iodine solution.Moisten the knife with thiocyanate solution (spectators can againdeceivesay it's alcohol). Next start yourselfcutwith a knife. Appearsblood.
For removingbloodwe also usecomplexation reaction:
[ Fe( SCN) 6 ] 3 + 6 F [ FeF 6 ] 3 + 6 SCN .
Simplified:Fe( SCN) 3 + 3 NaFFeF 3 + 3 NaSCN.
Iron fluoride complex(III) colorless. That's why,if you wipe itwoundcotton wool soaked in a solution of sodium fluoride, the thiocyanate complex is destroyed and a more stable complex is formed [FeF 6 ] 3 . Blooddisappears. The audience is shown that there is no wound on the palm.
Experiences for little ones
Potato becomes a submarine
AssubmarineWe use regular potatoes. We need one potato tuber, liter jar or a large beaker and table salt. Pour half a jar or glass of water and lower the potato. She will drown. Add a saturated salt solution to a jar (glass). The potatoes will float. If you want it to be immersed in water again, just add water to the jar. Why not a submarine?
Potatoes drown because... it is heavier than water. Compared to a salt solution, it is lighter, which is why it floats to the surface.
Hung bubble
OnPour baking soda into the bottom of a beaker or small jar and pour some table vinegar. Carbon dioxide will be released. It is heavier than air and will accumulate at the bottom of the jar. But carbon dioxide is colorless. You won't see him. However, you can make sure that it really is in the jar using soap bubbles. Blow a bubble into the jar. It will hang in it at the border of carbon dioxide and air.
Painting nails
Dissolve a little copper sulfate in a glass and dip a nail into it. After some time, the nail will turn red and the solution will take on a greenish tint. This was a chemical reaction. A layer of copper has formed on the surface of the nail.
Ants chemists
Antscapable of producingacidant . It is very easy to verify this. Enough to goin the forestAndtake with youthe chemist's faithful companionindicator paper. Find an anthill and, carefully, so as not to damage it, lower the straw into it for a while. Take it out and moisten it with a drop of water. Touch the wet straw to the indicator paper. Its color will indicate the presence of acid.
The experiment illustrates how sulfuric acid burns sugar in air in the presence of water.
Sulfuric acid greedily absorbs water and is able to extract this water even from sugar molecules. This reaction turns the sugar into charcoal and releases gases that foam the charcoal and push it out of the glass.
Pour powdered sugar into a glass.
Add water to the powdered sugar and mix everything thoroughly.
Add a little sulfuric acid to the solution of water and powdered sugar and continue stirring until the solution begins to darken and rise.
powdered sugar
water
sulfuric acid
chem. cup
syringe
glass rod
In a black, black forest stood a black, black house. In this black-black house there was black-black….
Hmmm... Children's horror stories are no longer in fashion. But there is very spectacular experience about black sugar. When concentrated sulfuric acid is added to powdered sugar moistened with water. The reaction of the uninitiated is much more violent than to fictitious stories with an unexpected ending.
How does this happen, and why does a black, solid, porous object form from snow-white sugar and a clear liquid?
Sucrose is a disaccharide with the formulaC 12 H 22 O 11 . How can we see that the ratio of atomsN AndABOUT the same as that of water - two hydrogen for one oxygen.
Concentrated sulfuric acid absorbs water from the sugar and the remaining carbon is released as charcoal.
Like most sulfuric acid reactions, this reaction is exothermic, meaning it produces heat. Therefore, the water evaporates, leaving only a dry solid residue.
2C 12 N 22 ABOUT 11 + 2H 2 SO 4 = 23C + CO 2 + + 2SO 2 + 24H 2 ABOUT
The gases produced in the process foam the carbon and it becomes porous.
Spectacular. The only pity is that carbon is released in the form of graphite, and not in its other modification - diamond.
The experiment demonstrates how sulfuric acid burns organic compounds. A similar process occurs in the stomach of mammals.
Sulfuric acid greedily absorbs water and is able to extract this water even from ordinary products. During this reaction, sugar, found in almost all foods, turns into coal.
Pour sulfuric acid into the vessel.
Throw an orange, chocolate, hamburger, and French fries into the acid. Mix everything.
After an hour and a half, we evaluate the result.
concentrated sulfuric acid
hamburger
chocolate
french fries
orange
glass vessel
In a solution of silicate glue with water, when copper sulfate is added, a “colloidal garden” will begin to grow.
Some time after adding a few pinches of copper and iron sulfate to a solution of silicate glue with water, a “colloidal garden” that resembles algae will begin to grow. The color of this "chemical algae" depends on the salt of the metal that is immersed. Copper salts are light blue, iron salts are dark green.
Pour silicate glue into a glass vessel, add water in a ratio of 1:1 or 1:2 and mix.
In a plastic cup, make a solution of copper sulfate and water.
We take a solution of copper sulfate into a glass tube with a bulb and, lowering the tube to the bottom of the vessel, release the solution of copper sulfate in portions.
Pour a pinch of copper and iron sulfate into a jar.
glass jar
water
silicate glue
copper sulfate
inkstone
glass tube with pear
spatula or spoon
plastic cup
Useful tips
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 they can show clearly how this or that thing, this or that phenomenon works.
In these experiments, children will not only learn something new, but also learn create differentcrafts, with which they can then play.
1. Experiments for children: lemon volcano
You will need:
2 lemons (for 1 volcano)
Baking soda
Food coloring or watercolor paints
Dishwashing liquid
Wooden stick or spoon (if desired)
1. Cut off the bottom of the lemon so it can be placed on a flat surface.
2. On the back side, cut out a piece of lemon as shown in the image.
* You can cut off half a lemon and make an open volcano.
3. Take the second lemon, cut it in half and squeeze the juice into a cup. This will be the reserved lemon juice.
4. Place the first lemon (with the cut out part) on the tray and use a spoon to “squeeze” 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 inside the lemon, but do not stir.
6. Pour dish soap inside the lemon.
7. Add a spoonful to the lemon baking soda. The reaction will begin. You can use a stick or spoon to 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 made from chewing worms
You will need:
2 glasses
Small capacity
4-6 gummy worms
3 tablespoons baking soda
1/2 spoon of vinegar
1 cup water
Scissors, kitchen or stationery knife.
1. Using scissors or a knife, cut lengthwise (precisely lengthwise - it won't be easy, but be patient) each worm into 4 (or more) pieces.
* The smaller the piece, the better.
*If the scissors do not 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 into it one by one.
* The experiment can be repeated if you wash the worms 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 of clear nail polish to a bowl of water. Watch how the varnish spreads 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 (this happens quickly) start turning the paper and look at the rainbow that appears on it.
* To better see a rainbow on paper, look at it under the sun's rays.
4. Experiments at home: rain cloud in a jar
As small drops of water accumulate in a cloud, they become heavier and heavier. Eventually 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 using 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. Have your child start dripping food coloring onto the “cloud” until it starts to “rain” - drops of coloring begin to fall to the bottom of the jar.
During the experiment, explain this phenomenon to your child.
You will need:
Warm water
Sunflower oil
4 food colors
1. Fill the jar 3/4 full with warm water.
2. Take a bowl and stir 3-4 tablespoons of oil and a few drops of food coloring into it. IN in this example 1 drop of each of 4 dyes was used - red, yellow, blue and green.
3. Using a fork, stir the coloring and oil.
4. Carefully pour the mixture into a jar of warm water.
5. Watch what happens - the food coloring will begin to slowly fall through the oil into the water, after which each drop will begin to disperse and mix with the other drops.
* Food coloring dissolves in water, but not in oil, because... oil density less water(that’s why it “floats” on the water). The dye droplet is heavier than the oil, so it will begin to sink until it reaches the water, where it will begin to disperse and look like a small fireworks display.
6. Interesting experiments: ina circle in which the colors merge
You will need:
- 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
Skewer or screwdriver (to make holes in the paper wheel).
1. Select 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 cardboard.
4. TO back side Glue the second template onto the cardboard circle.
5. Use a skewer or screwdriver to make two holes in the circle.
6. Thread the thread through the holes and tie the ends into a knot.
Now you can spin your 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. Place 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 the center of the plastic sheet and fold it like a ball to make a jellyfish head. Tie a thread in the area of the jellyfish's "neck", but not too tightly - you need to leave a small hole through which to pour water into the jellyfish's head.
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 approximately 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 a bottle with water and put your jellyfish in it.
9. Add a couple drops of blue or green food coloring.
* Close the lid tightly to prevent water from spilling out.
* Let 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 glass or bowl
Plastic bowl
1 cup Epsom salts (magnesium sulfate) - used in bath salts
1 cup hot water
Food coloring.
1. Place Epsom salts in 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 is not so hot that the glass will crack.
4. After freezing, transfer the solution to the main compartment of the refrigerator, preferably on the top shelf, and leave overnight.
The growth of crystals will be noticeable only after a few hours, but it is better to wait overnight.
This is what the crystals look like the next day. Remember that crystals are very fragile. If you touch them, they will most likely immediately break or crumble.
9. Experiments for children (video): soap cube
10. Chemical experiments for children (video): how to make a lava lamp with your own hands
Municipal budgetary educational institution
"Average comprehensive school No. 35" Bryansk
Entertaining experiments in chemistry
Developed
chemistry teacher of the highest category
Velicheva Tamara Alexandrovna
When conducting experiments, it is necessary to observe safety precautions and skillfully handle substances, utensils and instruments. These experiments do not require complex equipment or expensive reagents, and their effect on the audience is enormous.
"Golden" nail.
10-15 ml of copper sulfate solution is poured into a test tube and a few drops of sulfuric acid are added. An iron nail is immersed in the solution for 5-10 seconds. A red coating of copper metal appears on the surface of the nail. To add shine, wipe the nail with filter paper.
Pharaoh's snakes.
Crushed dry fuel is placed in a heap on the asbestos mesh. Norsulfazole tablets are placed around the top of the slide at equal distances from each other. During the demonstration of the experiment, the top of the slide is set on fire with a match. During the experiment, make sure that three independent “snakes” are formed from three norsulfazole tablets. To prevent the reaction products from sticking together into one “snake”, it is necessary to correct the resulting “snakes” with a splinter.
Explosion in a bank.
Take for experience tin can from a coffee container (without a lid) with a capacity of 600-800 ml and punch a small hole in the bottom. The jar is placed on the table upside down and, having covered the hole with damp paper, a gas outlet tube from Kiryushkin’s device is brought from below to fill it with hydrogen ( the jar is filled with hydrogen for 30 seconds). Then the tube is removed and the gas is ignited with a long splinter through the hole in the bottom of the jar. At first the gas burns calmly, and then a hum begins and an explosion occurs. The can jumps high into the air and flames burst out. The explosion occurs because an explosive mixture has formed in the can.
"Butterfly Dance"
For the experiment, “butterflies” are made in advance. The wings are cut out of tissue paper and glued to the body (pieces of a match or toothpick) for greater stability in flight.
Prepare a wide-mouth jar, hermetically sealed with a stopper into which a funnel is inserted. The diameter of the funnel at the top should be no more than 10cm. Acetic acid CH 3 COOH is poured into the jar so much that the lower end of the funnel does not reach the surface of the acid by about 1 cm. Then several tablets of sodium bicarbonate (NaHCO 3) are thrown through a funnel into a jar of acid, and the “butterflies” are placed in the funnel. They begin to “dance” in the air.
The “butterflies” are held in the air by a stream of carbon dioxide formed as a result of a chemical reaction between sodium bicarbonate and acetic acid:
NaHCO 3 + CH 3 COOH = CH 3 COONa + CO 2 + H 2 O
Lead coat.
A human figure is cut out of a thin zinc plate, cleaned well and placed in a glass with a solution of tin chloride SnCl 2. A reaction begins, as a result of which the more active zinc displaces the less active tin from the solution:
Zn + SnCl 2 = ZnCl 2 + Sn
The zinc figurine begins to become covered with shiny needles.
"Fire" cloud.
Flour is sifted through a fine sieve and flour dust is collected, which settles far along the sides of the sieve. It is dried well. Then two full teaspoons of flour dust are introduced into the glass tube, closer to the middle, and slightly shaken along the length of the tube by 20 - 25 cm.
Then the dust is strongly blown out over the flame of an alcohol lamp placed on a demonstration table (the distance between the end of the tube and the alcohol lamp should be about one meter).
A “fire” cloud is formed.
"Star Rain.
Take three teaspoons of iron powder, the same amount of ground charcoal. All this is mixed and poured into a crucible. It is fixed in a tripod and heated on an alcohol lamp. Soon the starry rain begins.
These hot particles are ejected from the crucible by carbon dioxide produced when coal burns.
Change in color of flowers.
In a large battery glass, prepare a mixture of three parts of diethyl ether C 2 H 5 ─ O ─ C 2 H 5 and one part (by volume) of a strong ammonia solution NH 3 ( there should be no fire nearby). Ether is added to facilitate the penetration of ammonia into the cells of the flower petal.
Individual flowers or a bouquet of flowers are dipped into an ether-ammonia solution. At the same time, their color will change. Red, blue and purple flowers will turn green, white ( White Rose, chamomile) - will turn into dark, yellow ones will retain their natural color. The changed color is retained by the flowers for several hours, after which it becomes natural.
This is explained by the fact that the color of the petals of fresh flowers is caused by natural organic dyes, which have indicator properties and change their color in an alkaline (ammonia) environment.
List of used literature:
Shulgin G.B. This is fascinating chemistry. M. Chemistry, 1984.
Shkurko M.I. Entertaining experiments in chemistry. Minsk. People's Asveta, 1968.
Aleksinsky V.N. Entertaining experiments in chemistry. Teacher's manual. M. Education, 1980.