Are there any small physical or chemical experiments that can be done at the birthday party?

Experiment: put a small amount of potassium permanganate crystal on the mirror (or glass), drop 2 or 3 drops of concentrated sulfuric acid on potassium permanganate, dip it with a glass rod, and touch the wick of the alcohol lamp, and the alcohol lamp will light up immediately.

2. Build an "underwater garden"

Sodium silicate (Na2SiO3) was dissolved in water to make water glass with 40% solute mass fraction, and then it was gently mixed with sodium silicate.

Crystal grains of salts, such as chlorides of cobalt, iron, copper, nickel and lead, sulfates of aluminum, iron, copper and nickel, cobalt,

Nitrates of iron, copper and nickel, added to water glass (be careful not to shake), are colorful "flowers".

It grew up slowly.

Step 3 paint

Experimental principle

FeCl3 _ 3 _ 3 solution is blood red in the presence of potassium thiocyanate (KSCN), blue in the presence of potassium ferrocyanide [K4 [Fe (CN) 6]], green in the presence of potassium ferricyanide [K3 [Fe (CN) 6]] and purple in the presence of phenol. FeCl3 _ 3 solution is yellow when sprayed on white paper.

Experimental supplies

White paper, brush, sprayer, wooden frame, nail clippers.

Ferric chloride solution, potassium thiocyanate solution, concentrated potassium ferrocyanide solution, concentrated potassium ferrocyanide solution, concentrated phenol solution.

experimental procedure

(1). Dip in potassium thiocyanate solution and concentrated potassium ferrocyanide solution,

Concentrated solution of potassium ferricyanide and concentrated solution of phenol are coated on white paper.

(2) Dry the paper and nail it on the wooden frame.

(3) Spray FeCl _ 3 solution on white paper with pictures with a sprayer.

4, wood carving or bamboo carving (word) method

Reaction principle: dilute sulfuric acid is heated into concentrated sulfuric acid, which has a strong dehydration effect and makes cellulose

(C6H 10O5)n loses water and carbonizes, so it appears black or brown. Wash off excess sulfuric acid and put it on a wood (bamboo) machine.

Get black or brown flowers or words.

Experimental steps: Draw flowers or write on wood (or bamboo) with a brush dipped in 5% dilute sulfuric acid.

Words. After drying, put the wooden (bamboo) container on a small fire for a period of time, wash it with clear water and put it on the wooden (bamboo) container.

Get a black or brown pattern or handwriting.

5, protein traces

Take an egg, wash the oil on the surface and dry it. Dip the brush in acetic acid and write on the eggshell. After the acetic acid volatilizes, cook the egg with dilute copper sulfate solution, and peel off the eggshell after the egg cools, leaving clear blue or purple handwriting on the egg white, but leaving no trace on the eggshell.

This is because acetic acid can dissolve a small amount of protein after dissolving eggshells. Egg white is a globulin composed of amino acids, which hydrolyzes under weak acidic conditions to produce peptides and other substances. The peptide bonds in these substances are complexed with Cu2+ and appear blue or purple.

6, automatic long-haired duck:

Cut the aluminum skin into duck shape (rabbit, cat, mouse ... whatever), dip a cotton swab in HgNO3 solution and coat it on the aluminum skin. After a few minutes, dry the mercury nitrate on the aluminum skin. Then you can see that the aluminum duck automatically grows white hair!

Experimental principle: aluminum is an active metal, but the reaction between aluminum and air is prevented because of the dense oxide film on the surface of aluminum. After coating with HgNO3 solution, the dense oxide film was destroyed and Al-Hg alloy was formed, which made it impossible to form a dense oxide film on Al surface. Al can continuously react with oxygen in the air to produce white Al2O3.

Precautions: HgNO3 is a highly toxic compound, so we should pay attention to the protective measures during the experiment!

7. Non-combustible cotton cloth

Cotton cloth is made of cotton. The main chemical composition of cotton is cellulose molecules, which contain carbon, hydrogen and oxygen, so it is flammable. The cloth strips are pre-soaked in 30% sodium phosphate solution, dried in 30% alum solution, and then dried. In this way, there are two chemicals on the cloth, sodium phosphate and alum. Sodium phosphate is alkaline in water, while alum is acidic in water. After their reaction, they not only produce water, but also produce water-insoluble aluminum hydroxide. So in fact, the cotton sliver is wrapped with an aluminum hydroxide film, which becomes aluminum oxide and water after heating. It is this dense alumina film that protects aluminum bars from fire. The treated cotton cloth is widely used in industrial and agricultural production and national defense construction.

8. The glass rod ignited the ice.

Glass rods can ignite ice cubes without matches and lighters. As long as you gently use a glass rod, the ice will burn immediately and last for a long time. You can do an experiment if you are interested. First, pour 1-2 small potassium permanganate into a small dish, gently grind it into powder, then drop a few drops of concentrated sulfuric acid and stir it evenly with a glass rod. The glass rod immersed in this mixture is an invisible small torch, which can ignite alcohol lamps or ice cubes. However, put a small piece of calcium carbide on the ice in advance, so that the ice will burn as long as it is gently touched with a glass rod. Please answer after the experiment.

There is a simple reason. Calcium carbide (chemically called calcium carbide) on the ice surface reacts with a small amount of water on the ice surface, and the calcium carbide gas (chemically called acetylene) produced by this reaction is flammable. Because concentrated sulfuric acid and potassium permanganate are both strong oxidants, they are enough to oxidize calcium carbide gas, reach the ignition point immediately, and make calcium carbide gas burn. In addition, because the reaction between water and calcium carbide is exothermic, the combustion of calcium carbide gas is exothermic, and more and more water is melted into ice cubes, so the reaction of calcium carbide is more and more rapid, with more and more calcium carbide gas and more fires.

9. White flowers turn blue.

Instruments: iron frame, iron clip, evaporating dish, dropper.

Drugs: zinc powder, iodine tablets, ointment.

Methods: Put 2g of zinc powder and 2g of broken iodine tablets into an evaporating dish, mix them evenly, hang a white flower right above the evaporating dish, and coat the white flower with batter.

A white flower, now it is necessary to "make a drop of water into purple smoke, and purple smoke into an orchid." Then use a rubber dropper to absorb cold water and add one or two drops to the mixed powder. Then purple smoke and white fog rose, and the clouds rushed to embrace the white flowers, dyed them into orchids and smoked them once or twice. Blue flowers are more vivid.

Principle: Iodine tablets and dry zinc powder are not easy to combine directly at room temperature. After adding a small amount of water as a catalyst, they immediately react violently to generate zinc iodide and release a lot of heat, so that unreacted iodine sublimates into purple smoke, and the water is vaporized by heating and condenses into white fog in the air. Iodine and flour on white paper flowers are blue, so purple smoke becomes blue flowers.

10, spontaneous combustion-reaction of sugar with potassium chlorate

Experimental principle

When concentrated sulfuric acid reacts with sugar, it releases heat, which can promote the decomposition of potassium chlorate and release oxygen. Oxygen further oxidizes sugar, and the oxidation of sugar releases a lot of heat, which is big enough to make sugar burn to produce flames.

Experimental steps and phenomena

Mix the powdered sugar with the same amount of potassium chlorate and put it in an evaporating dish. Gently dig a dent in the top of the mixture and drop a drop of concentrated sulfuric acid into the dent, and spontaneous combustion will occur.

Note: This experiment should be carried out in a fume hood.

1 1, volcanic eruption

[experimental principle]

The fierce reaction between potassium permanganate and glycerol releases a lot of heat, which makes the solid residue produced by the decomposition of ammonium dichromate eject with the generated gas.

[experimental operation]

Pile a square mud in the center of the board and put a crucible on it. A small "hill" is built around the crucible with mud, and a "crater" is above the crucible at the top of the mountain. A mixture of 5 g potassium permanganate and 1g strontium nitrate was piled up in the center of the crucible buried in the hill, and 10g ammonium dichromate powder was piled up around the mixture. Drop a few drops of glycerin on potassium permanganate with a long dropper, and keep people away. After a while, you can see a purple flame, followed by a green "volcanic ash".

12, fire and water compatibility

Fill a glass with half a glass of water, put a dozen potassium chlorate crystals at the bottom of the water, and then put a few small yellow phosphorus in the potassium chlorate crystals with tweezers. Then use a glass straw to suck a little concentrated sulfuric acid and transfer it to the mixture of potassium chlorate and yellow phosphorus, and then there will be a fire in the water. If there is fire in the water, isn't it "compatible with water and fire"?

Putting potassium chlorate into water, wherein potassium chlorate is an oxygen-containing compound; Then add yellow phosphorus, which is very flammable. Because it is isolated from oxygen in the air in water, it will not spontaneously ignite. However, when concentrated sulfuric acid is added, concentrated sulfuric acid reacts with potassium chlorate to form chlorate, which is unstable and releases oxygen. Oxygen reacts with yellow phosphorus to burn. This reaction is particularly intense, so it can also be carried out in water, so that fire and water are in the same cup. Phosphorus is oxidized into phosphorus pentoxide, which reacts with water to produce phosphoric acid.

13, starlight in liquid

In a large test tube, add a few milliliters of anhydrous ethanol (or 90% ethanol), then slowly drop the same amount of concentrated sulfuric acid, and line the back of the test tube with a piece of dark blue paper. After shaking the test tube, turn off the light, pick some potassium permanganate crystals with a spoon and slowly sprinkle them on the liquid surface. The crystal will gradually fall in the solution, and you can see Mars, just like the starlight in autumn night, and there will be a slight crack. So, why does the mixture of potassium permanganate and alcohol glow?

Because potassium permanganate comes into contact with concentrated sulfuric acid, it produces oxygen, which has strong oxidizing power and can make the alcohol in the mixed solution burn and emit sparkling sparks. When viewed in a dark place, the sparks are particularly bright.

15, small charcoal dance

Take a test tube, fill it with 3-4g solid potassium nitrate, then fix it upright on an iron frame with an iron clip, and heat the test tube with an alcohol lamp. When the solid potassium nitrate gradually melts, take a piece of charcoal the size of a small bean, put it in a test tube and continue to heat it. After a while, you will see the small carbon block suddenly jumping up and down on the liquid level in the test tube, and then turn it over by itself, like dancing, giving off a fiery red light, which is very interesting. Please enjoy the beautiful dance of Little Charcoal. Can you answer why Xiao Tan dances?

answer

It turned out that when the small charcoal was just put into the test tube, the temperature of potassium nitrate in the test tube was low, so the small charcoal was still lying there. After heating the test tube, the temperature rises to make the small charcoal reach the ignition point. At this time, there is a fierce chemical reaction with potassium nitrate, which releases a lot of heat and makes the small charcoal burn and glow immediately. Because potassium nitrate decomposes at high temperature to release oxygen, this oxygen immediately reacts with small charcoal to generate carbon dioxide gas, which pushes small charcoal up at once. After the charcoal jumped up, it was out of contact with the potassium nitrate liquid below, the reaction was interrupted, and carbon dioxide gas was no longer produced. When the small charcoal falls back to potassium nitrate due to gravity, it reacts again and jumps up for the second time. In this cycle, Xiao Tan will keep jumping up and down.