It’s all in the high school books, and “high school kids” sounds weird
These are the other things besides the books:
(1) Firecrackers to celebrate
Supplies: mortar, glass pieces, dropper, glass rod, paper.
Potassium chlorate, red phosphorus, alcohol, paste.
Principle: Potassium chlorate is a strong oxidant and red phosphorus is flammable. Chemical reactions easily occur between the two. Burning occurs when they are mixed with a medicine spoon. A violent explosion occurs when the mixture is struck.
5KClO3+6P=5KCl+3P2O5
Operation: Grind 2 grams of potassium chlorate crystals into powder in a mortar and pour it onto a glass piece. Take 0.6 grams of red phosphorus and place it next to the potassium chlorate powder. Use a dropper to absorb alcohol and drop it on the two drugs to make the drugs moist, then use a glass rod to mix them evenly into a paste, and divide them into three equal parts. After they are dry, wrap them in paper and stick them tightly.
When the celebration begins, three paper bags are thrown hard against the cement floor or bricks, and three cannons will sound.
(2) Glass rod ignition
Supplies: glass rod, glass piece, alcohol lamp. 98% concentrated sulfuric acid, potassium permanganate.
Principle: Potassium permanganate reacts with concentrated sulfuric acid to produce manganese heptaoxide, a brown oily liquid with extremely strong oxidizing ability. As soon as it touches alcohol, a strong oxidation-reduction reaction occurs, and the heat released causes the alcohol to reach the ignition point and burn.
2KMnO4＋H2SO4＝K2SO4＋Mn2O7＋H2O
2Mn2O7＝4MnO2＋3O2↑
C2H5OH＋3O2→2CO2＋3H2O
Operation: Use the small end of a medicine spoon to take a little ground Potassium permanganate powder, placed on a glass piece and made into a small pile. Dip the glass rod into concentrated sulfuric acid first, and then stick some potassium permanganate powder on it. If you touch the wick of the alcohol lamp, the wick will burn immediately, and four or five alcohol lamps can be lit at one time.
Note: Manganese heptaoxide is very unstable and can decompose into manganese dioxide and oxygen at 0°C. Therefore, after the glass rod is dipped in concentrated sulfuric acid and potassium permanganate, the alcohol lamp should be lit immediately. Otherwise, over time, the dimanganese heptaoxide will be decomposed and the alcohol lamp will no longer be lit.
(3) Steel wire ignition
Supplies: steel wire, bottle caps, candles, sulfur powder.
Principle: When the sulfur on the iron wire is used to burn, the flame is very light and cannot be seen from a distance during the day. It seems that the candle is really lit by the wire.
Operation: Flatten one end of the bicycle steel wire into a groove in advance, put some sulfur powder in the groove, heat it to melt and catch fire, and set aside. Light a candle and place it on the table. At this time, use a bottle cap to cover the candle flame, and then use a steel wire to touch the white smoke rising from the candle wick, and the candle flame will rekindle. It can be put out again and ignited again. It lights up and goes out like this, which makes people secretly marvel.
(4) Finger lighting
Supplies: mortar, small wooden board.
Candles, potassium chlorate, sulfur.
Principle: The embers of the candle cause the sulfur to burn. The heat released when sulfur burns causes potassium chlorate to decompose to produce oxygen, so the sulfur burns more vigorously and the embers catch fire.
Operation: Take 1 gram of potassium chlorate and 0.5 grams of sulfur, grind them into very fine powder in a mortar, and then mix them evenly. Or you can use ten matches to scrape off the scalp medicine and grind it finely.
Fix a candle to the small board and light it. Dip your fingers into some mixed powder beforehand. During the performance, blow out the candle, and while there are still embers, gently touch the wick with your finger dipped in medicinal powder, and the candle will re-ignite. It can be blown out again and lit again.
Note: The wick of the candle is about 1.5 cm long. This way there will be embers after blowing them out. If you use finely ground matchstick powder, you can only stick a thin layer on your fingers. If you use too much, the scalp medicine on your fingers will catch fire and may burn your fingers.
(5) Chlorine gas ignition
Supplies: 250 ml wide-mouth bottle, separatory funnel, catheter, glass sink, gas collecting bottle, frosted glass slide, test tube, dropper.
Calcium carbide, water, concentrated hydrochloric acid, potassium permanganate.
Principle: The reaction of calcium carbide and water produces acetylene. Potassium permanganate reacts with hydrochloric acid to produce chlorine gas.
The heat released from the reaction between chlorine and acetylene ignites the acetylene, which then continues to burn in the air.
CaC2+2H2O→Ca(OH)2+C2H2↑
2KMnO4+16HCl＝2KCl+2MnCl2+5Cl2↑+8H2O
C2H2+Cl2→2C+2HCl
2C2H2+5O 2→4CO2＋2H2O
Operation: The experimental device is shown in Figure 15-1. Put 10 grams of small pieces into the jar to prepare acetylene stone. Gently unscrew the stopcock of the separatory funnel and let the water drip slowly. After the air in the jar is drained, use the drainage method to collect a bottle of acetylene. Cover the mouth of the bottle with a frosted glass slide and place it upright on the table. Take another test tube and put 0.5 grams of potassium permanganate crystals into it. Add 2 drops of concentrated hydrochloric acid and chlorine gas will be generated and fill the test tube. At this time, take off the frosted glass slide on the acetylene bottle with your left hand, and pour the chlorine gas in the test tube into the acetylene bottle with your right hand. When acetylene and chlorine meet, they immediately catch fire and emit a bright, smoky flame.
(6) Fire in a cup
Supplies: 600 ml beaker, evaporating dish, crucible, tweezers.
Ether, potassium, fine sand.
Principle: Potassium and ether do not react at room temperature. When they are poured into water, the potassium and water immediately produce hydrogen gas and catch fire, causing a violent combustion phenomenon.
2K＋2H2O＝2KOH＋H2↑
2H2＋O2 2H2O
C2H5OC2H5＋6O2 4CO2＋5H2O
Operation: Put a thick layer of fine sand at the bottom of the beaker, and put it on top of the sand An evaporating dish filled with 5 ml of water. Pour 2 ml of ether into the crucible, and then add a piece of potassium the size of a mung bean. When a mixture of ether and potassium was poured into the evaporating dish, a fire immediately broke out in the cup.
(7) Dripping water to make fire
Supplies: 600 ml beaker, evaporating dish, tweezers, dropper.
Filter paper, fine sand, sodium peroxide, white phosphorus.
Principle: Sodium peroxide reacts with water to produce oxygen and release a large amount of heat, causing white phosphorus to catch fire and generate a large amount of phosphorus pentoxide white smoke.
Operation: Spread a layer of fine sand on the bottom of the 600 ml beaker, and place an evaporating dish on the sand. Take 2 grams of sodium peroxide and place it in an evaporating dish. Use tweezers to pick up 2 soybean-sized pieces of white phosphorus. Use filter paper to absorb the water and place it on the sodium peroxide. Use a dropper to add 1 to 2 drops of water to the sodium peroxide, and the white phosphorus will burn immediately, producing thick white smoke.
(8) Spark in liquid
Supplies: Large test tube , iron stand, iron clamp.
98% concentrated sulfuric acid, alcohol, potassium permanganate.
Principle: The contact between potassium permanganate and concentrated sulfuric acid will produce highly oxidizing dimanganese heptaoxide and release heat at the same time. Manganese heptaoxide decomposes into oxygen, causing the alcohol in the liquid to burn. However, due to the small amount of oxygen, only a few sparks can be emitted, but the alcohol cannot be continuously burned.
Operation: Take a large test tube, inject 5 ml of alcohol into the test tube, and then slowly add 5 ml of concentrated sulfuric acid along the wall of the test tube without shaking the test tube. Fix the test tube vertically on the iron stand. At this time, the liquid in the test tube is divided into two layers, the upper layer is alcohol and the lower layer is concentrated sulfuric acid. Use a medicine spoon to take some potassium permanganate crystals and slowly sprinkle them into the test tube. The crystals gradually fall to the junction of the two liquids. Soon there will be sparks at the junction. If done in a dark place, the sparks will appear extra bright.
Note: Do not use too much potassium permanganate, otherwise, the reaction will be too violent and the liquid in the test tube will rush out.
(9) Ice cubes catch fire
Supplies: large porcelain plate, dropper.
Carbide, potassium, ice.
Principle: Water and potassium react violently, causing the generated hydrogen to burn. The combustion of hydrogen ignites the acetylene produced by the reaction of calcium carbide and water. The heat generated by combustion further melts ice into water. The action of water and calcium carbide continuously produces acetylene, so the flame burns more and more vigorously. The flame gradually extinguishes until the calcium carbide is used up.
Operation: Take a large piece of ice and place it in a large porcelain plate. Dig a shallow pit on the ice and put in a small piece of calcium carbide and a small piece of potassium. Then a few drops of water were poured into the shallow pit, and a ball of fire and smoke immediately appeared, as if the ice was on fire.
(10) Starlight Flying
Supplies: 20 ml plastic bottle, needle, alcohol lamp.
Gallite powder, magnesium powder, reduced iron powder.
Principle: When gall alum powder, magnesium powder and reduced iron powder fall on the flame, the copper ions of gall alum make the flame appear green. The magnesium powder and iron powder are in contact with the air due to their small size. It has a large surface and is easily burned by flames, so it can combine with oxygen in the air to form magnesium oxide and ferric oxide.
2Mg＋O2 2MgO
3Fe＋2O2 The heat generated by the Fe3O4 reaction makes ferroferric oxide glow red, causing magnesium oxide to reach an incandescent state, so tiny red light and dazzling white light appear. Because the metal powder does not fall on the flame and burn at the same time, and is blown away by the hot air flow during oxidation, red and white light radiate in all directions, flashing like stars.
Operation: Take 1 gram each of bile alum powder, magnesium powder and reduced iron powder. Mix them well and put them into a small plastic bottle. Use a needle to punch some small holes in the bottom of the bottle. Then gently tap the plastic bottle over the flame of the alcohol lamp. When the powder in the bottle falls on the flame, the flame appears green. Above the green flames, red and white stars are flying, and the scenery is very beautiful.
(11) Burning in water
Supplies: mortar, glass sink, plastic bottle about 4 cm in diameter, iron rod, fuse.
Potassium nitrate, sulfur powder, charcoal powder, fine sand.
Principle: When black powder burns in water, the large amount of smoke and gas ejected is enough to flush away the water without affecting the continuation of the reaction. The main chemical reaction of black powder combustion is:
S＋2KNO3＋3C ignites K2S＋N2↑＋3CO2↑
Operation: Take 5 parts of potassium nitrate, 1 part of sulfur powder, 1 part of charcoal powder, and grind them separately Then put it on the paper and mix it repeatedly to make black gunpowder and set aside.
Take a plastic bottle with a diameter of about 4 cm and cut it into a cylinder with a height of about 6 cm and a bottom. First put about 2 cm thick fine sand into the cylinder, and then fill it with black powder. After each small amount is put in, pound it firmly with an iron rod. After filling it to the mouth of the barrel, insert the fuse (it is made of cotton rope soaked in 30% potassium nitrate solution and dried in the sun.) Then press the black powder tightly. Put the plastic tube filled with gunpowder gently into the glass sink filled with water. The mouth of the tube should be about 1 cm above the water surface.
Light the fuse, and soon a large amount of smoke and flames will spray out from the plastic tube. The burning gradually spreads underwater until the black powder is burned out. Because there is a small amount of unburned charcoal powder dispersed in the water, the water turns brown-black.
(12) Fire in water
1
Supplies: 200 ml beaker, 2 ml pipette, tweezers, medicine spoon.
Water, 98% concentrated sulfuric acid, potassium chlorate, white phosphorus.
Principle: The action of potassium chlorate and concentrated sulfuric acid produces easily decomposed chloric acid and chlorine dioxide. Chlorine dioxide easily decomposes to produce chlorine and oxygen. At the same time, it releases heat so that white phosphorus reaches the ignition point and burns in oxygen to produce phosphorus pentoxide. Phosphorus pentoxide reacts with water to form phosphoric acid.
KClO3＋H2SO4＝HClO3＋KHSO4
4HClO3＝4ClO2↑＋O2↑＋2H2O
2ClO2＝Cl2＋2O2
4P＋5O2＝2P2O5
P2O5+3H2O=2H3PO4
Operation: Put 10 grams of potassium chlorate crystals in the beaker, slowly inject 100 ml of water, then use tweezers to pick up 2 to 3 pieces of white phosphorus the size of mung beans and place them in the middle of the potassium chlorate crystals. Then use a pipette to draw 2 ml of concentrated sulfuric acid and inject it into the junction of potassium chlorate and white phosphorus. At this time, the white phosphorus burns and emits fire.
Supplies: 400 ml beaker, tweezers, iron stand, iron clamps, test tubes, rubber stopper with catheter.
Potassium chlorate, manganese dioxide, white phosphorus, hot water at 40°C.
Principle: The temperature of the water reaches the ignition point of white phosphorus and there is oxygen, so the white phosphorus burns in the water.
Operation: Put 5 small pieces of white phosphorus the size of mung beans into a beaker containing half a cup of 40°C hot water.
Mix 6 grams of potassium chlorate and 2 grams of manganese dioxide evenly and put them in a test tube. Plug the opening of the tube tightly with a plug attached to the catheter. Heat the test tube.
When the nozzle of the oxygen-releasing tube is brought close to the white phosphorus, the white phosphorus burns immediately and emits a flickering fire.
(13) Charcoal makeup dance
Supplies: iron stand, iron clamps, alcohol lamp, large test tube, tweezers.
Charcoal, potassium nitrate.
Principle: Potassium nitrate melts first when heated and then decomposes into potassium nitrite and oxygen. When molten potassium nitrate comes into contact with charcoal, the heat released by the reaction burns the charcoal red, and the carbon dioxide produced pushes the charcoal up. After the charcoal and potassium nitrate are out of contact, they fall due to gravity. The charcoal just jumps up and down until it's done.
2KNO3 2KNO2+O2↑
C+O2=CO2
Operation: Take 5 grams of potassium nitrate and put it into a large test tube. Fix the test tube vertically on the iron stand. Use the outer flame of an alcohol lamp to heat the bottom of the test tube to melt the potassium nitrate. When gas is released, add a piece of charcoal as big as a soybean and continue heating. After a while, the charcoal turned from black to red and kept beating up and down in the test tube, giving off a bright fire light. Remove the alcohol lamp and the charcoal can still dance for a while.
(14) Chemical lamp
Supplies: iron stand, iron clamps, tweezers, large hard test tube, alcohol lamp.
Potassium nitrate, sulfur block.
Principle: The reaction between sulfur and molten potassium nitrate is very violent, releasing a large amount of heat, causing the potassium nitrite generated in the reaction to be heated and emit dazzling white light.
2KNO3 2KNO2+O2↑
S+O2=SO2
Operation: Fix the large test tube containing 5 grams of potassium nitrate vertically on the iron stand and heat the bottom of the test tube until it Potassium nitrate melts. At this time, take away the alcohol lamp and put sulfur blocks as big as soybeans into the test tube every half minute, and the test tube will continue to emit dazzling white light.
(15) Fireworks
Supplies: mortar, paper tube, fuse (made from cotton rope soaked in 30% potassium nitrate solution and dried in the sun).
Potassium chlorate, sulfur, charcoal powder, potassium nitrate, sodium nitrate, barium nitrate, strontium nitrate, sucrose, magnesium powder, antimony trisulfide.
Principle: The colors of red, green, purple, blue and yellow in fireworks are the flame reaction of certain metal elements in medicines.
Flame color: K, K+ (purple), Na, Na+ (yellow), Sr, Sr2+ (dark red), Ba, Ba2+ (yellow-green).
Operation: Prepare various fireworks according to the following formula (mass ratio).
Red: 4 potassium chlorate, 11 sulfur powder, 2 charcoal powder, 33 strontium nitrate.
Green: 9 potassium chlorate, 10 sulfur powder, 31 barium nitrate.
White: 3 sulfur powder, 12 potassium nitrate, 1 magnesium powder, 2 charcoal powder.
Purple: Potassium chlorate 7, sulfur powder 5, potassium nitrate 7, sucrose 2.
Yellow: 12 sulfur powder, 2 charcoal powder, 30 potassium nitrate, 5 sodium nitrate.
Blue: potassium nitrate 9, sulfur powder 2, antimony trisulfide 2.
Weigh the required drugs according to the quantity, grind them separately and mix them evenly, put them into the paper tube, press them tightly while loading, and insert the fuse after loading. When the fuse is ignited, the gunpowder will burn (or ignited by dripping concentrated H2SO4), emitting flames of various colors, which are very beautiful.
Note: When preparing gunpowder, each component must be ground separately and must not be mixed to prevent burning or explosion. There will be more smoke generated during the reaction, so this experiment is suitable to be conducted outdoors.
(16) Self-illuminating candles
Supplies: 6×6 cm square board, 30 ml reagent bottle, tweezers, dropper.
Carbon disulfide, white phosphorus, candles.
Principle: Drop the carbon disulfide solution of white phosphorus on the candle wick. The carbon disulfide will quickly evaporate, leaving behind small white phosphorus particles. When white phosphorus comes into contact with air, it oxidizes and releases heat violently, causing the white phosphorus to burn. When the white phosphorus burns, it lights the wick.
Operation: Take a lit candle and fix it on the wooden board. The wick should be long and loose. Inject 5 ml of carbon disulfide into the reagent bottle, then use tweezers to pick up a piece of white phosphorus the size of a broad bean and put it into the carbon disulfide, plug the bottle cap, and shake gently to dissolve the white phosphorus into a solution. Use a dropper to absorb a small amount of white phosphorus and carbon disulfide solution and drop it onto the candle wick. Soon, the candle wick spontaneously ignited.
(Seventeen) Volcanic Eruption
Supplies: Dropper.
Gypsum, potassium permanganate, ammonium dichromate, glycerin.
Principle: Potassium permanganate and glycerin undergo a violent redox reaction, and the heat released causes the glycerin to catch fire. Ammonium dichromate quickly decomposes when heated to produce nitrogen, causing the chromium trioxide powder to fly upward and burst into sparks.
Operation: Add calcined gypsum and water and knead it into a hill. Leave a crucible-sized pit at the top of the hill to dry and set aside.
In the middle of the pit on the top of the gypsum mountain, potassium permanganate powder is piled up and a small groove is pressed on top. Around the potassium permanganate, finely ground ammonium dichromate powder is piled. Use a dropper to absorb glycerin and drop 1 to 2 drops into the small tank of potassium permanganate. After a while, you can see purple-red flames erupting, followed by a lot of green "volcanic ash", covering the hillside. The scene is lifelike, like a volcanic eruption.
(18) Undersea volcanic eruption
1
Supplies: glass sink, 20 ml wide-mouth medicine bottle, plastic film, leather band, dropper.
Gypsum, sucrose, potassium chlorate, 98% concentrated sulfuric acid.
Principle: Concentrated sulfuric acid and potassium chlorate react to form chlorine dioxide that smells bad. Chlorine dioxide has extremely strong oxidizing power and can cause sucrose to burn violently.
Operation: Use calcined plaster and water to form a hill, embed a wide-mouth medicine bottle on the top of the hill, dry it and set aside.
Mix 10 grams of potassium chlorate and 10 grams of sucrose evenly and put them into a small bottle on the top of the gypsum mountain. Seal the mouth of the bottle with plastic film, tie it tightly with a rubber band, and then submerge the hill into the water in the sink. Use a dropper to absorb concentrated sulfuric acid, puncture the plastic film, and add a few drops of concentrated sulfuric acid. The volcano immediately erupted in the water, which was very spectacular.
2
Supplies: glass sink, ink bottle.
Boiling water, red ink.
Principle: Convection occurs between boiling water and cold water. The boiling water rises and the cold water falls.
Operation: Drop 10 drops of red ink into the empty ink bottle, then pour boiling water, tighten the bottle cap, and put it into the sink. Pour cold water into the sink until it covers about 5 cm of the bottle. Then gently unscrew the bottle cap, and the red water in the bottle slowly rises and sprays towards the water surface, like an undersea volcano erupting.
(19) Rhythm Explosion
Supplies: mortar, 60 ml Erlenmeyer flask, glass rod.
Iodine tablets, 30% concentrated ammonia.
Principle: Iodine reacts with concentrated ammonia to form hexaammonium triiodide. It is insoluble in water. When dried, it is extremely unstable and will explode at the slightest touch.
3I2＋7NH3＝NI3?6NH3＋3HI
2NI3?6NH3＝N2↑＋3I2＋12NH3↑
There is no danger in the explosion of evenly distributed hexaammonium triiodide.
Operation: Place 1 gram of iodine tablets in a mortar and add 5 ml of concentrated ammonia. After careful grinding for 3 minutes, a fine black solid of hexammine nitrogen triiodide was obtained. Add 50 ml of water, stir and pour into an Erlenmeyer flask. Shake the Erlenmeyer flask to evenly distribute the black powder in the water, then sprinkle on the stage and let it dry. After drying, dance on it and create rhythmic explosions as you dance.
(Twenty) Explodes on touch
Supplies: 2 test tubes, rubber stoppers with tubes, funnel, filter paper, medicine spoon, asbestos mesh, triangle stand, alcohol lamp.
Cotton, 2% silver nitrate solution, 2% dilute ammonia, calcium carbide.
Principle: The reaction of calcium carbide and water produces acetylene. Acetylene reacts with silver ammonia solution to produce silver acetylene.
CaC2+2H2O→Ca(OH)2+C2H2↑
C2H2+2Ag(NH3)2OH→C2Ag2↓+4NH3+2H2O Acetylene silver will explode and decompose into silver and carbon when it is hit or heated.
C2Ag2→2Ag+2C
Operation:
Add 3 ml of water into the test tube on the left side of Figure 15-4, then put 2 small pieces of calcium carbide into the test tube mouth. Put some cotton and plug the plug connected to the catheter. Let the generated acetylene continue to flow into the silver ammonia solution, and gray-white silver acetylene will precipitate. After the reaction stops, filter with filter paper, rinse, take out the sediment, place it on a clean asbestos mesh and divide it into several small piles the size of mung beans. Once it dries, it explodes when touched. You can also place the asbestos net on a tripod with a burning alcohol lamp underneath.
After a moment, the water evaporated and the silver acetylene exploded violently, and at the same time there was a fire.
(21) Indestructible handkerchief
1
Supplies: handkerchief, 100ml beaker, alcohol lamp, bamboo clips.
Alcohol.
Principle: Alcohol burns when exposed to fire and releases heat, which volatilizes a large amount of alcohol and water, taking away part of the heat. You can dissipate a lot of heat when you shake the handkerchief from side to side. In this way, the temperature of the flame is lowered and cannot reach the ignition point of the handkerchief.
Operation: Pour 20 ml of alcohol and 10 ml of water into the beaker, shake well, and soak the handkerchief in the solution. Use a bamboo clip to take out the handkerchief, gently squeeze out the alcohol, and then place it on a burning alcohol lamp to light it. When the handkerchief caught fire, the flames were huge. At this time, shake the handkerchief from side to side until it goes out. After the fire was extinguished, the handkerchief remained intact.
Supplies: handkerchief, glass rod, alcohol lamp.
Alcohol, saturated solution of sodium phosphate, saturated solution of alum.
Principle: After the handkerchief soaked in sodium phosphate and alum solution is dried, the aluminum hydroxide formed by sodium phosphate and alum will separate the cloth from the air. Therefore, the heat generated by the burning of alcohol cannot cause the handkerchief to reach the ignition point.
2KAl(SO4)2+3Na3PO4+6H2O=3NaH2PO4+3Na2SO4+K2SO4+2Al(OH)3↓
Operation: Soak the handkerchief in a saturated solution of sodium phosphate, take it out and dry it. Soak the handkerchief in a saturated solution of alum for a few minutes, then take it out to dry.
During the performance, pour some alcohol on the handkerchief, pick up the handkerchief with a glass rod, and light it on the burning alcohol lamp. The handkerchief caught fire and gave off a pale blue flame. After the flames went out, the handkerchief was not burned at all.
(22) Floral cloth in the fire
Supplies: floral cloth, thin wire, tweezers, alcohol lamp.
Mothballs
Principle: The chemical composition of mothballs is naphthalene, which is easy to burn. Part of the heat generated during combustion is used to sublimate naphthalene, so the temperature of the floral cloth that is close to the mothballs is lowered and cannot reach the ignition point of the cloth, so the cloth will not burn.
Operation: Wrap a mothball tightly with a small piece of floral cloth, tie it tightly with a thin iron wire, then clamp it with tweezers, place it on the flame of an alcohol lamp and light it. In a blink of an eye, the tiny floral cloth is raging. It was surrounded by fire, and thick black smoke was emitted from the fire. After blowing out the fire, I opened the cloth bag and saw that the mothballs had become smaller, but the calico remained the same as before and was not burned at all.
(Twenty-three) Strange absorbent cotton
Supplies: absorbent cotton, 100 ml beaker, glass rod, iron wire, and four iron clips.
Sodium phosphate saturated solution, alum saturated solution, 30% potassium nitrate solution, concentrated nitric acid (density 1.4 g/ml), concentrated sulfuric acid (density 1.84 g/ml).
Principle: The absorbent cotton soaked in sodium phosphate and alum solution is not easy to burn because there is a non-flammable protective film on the cotton fiber.
Absorbent cotton soaked in potassium nitrate solution burns easily because potassium nitrate decomposes when heated to release oxygen to support combustion.
2KNO3 2KNO2+O2↑
Soak the absorbent cotton in a mixture of 1 volume of concentrated nitric acid and 2 volumes of concentrated sulfuric acid for 15 minutes. Due to the esterification reaction between cotton fiber and nitric acid, it is extremely flammable. After taking out the cellulose trinitrate, washing it and drying it, the gunpowder cotton looks similar to the original absorbent cotton, but it burns quickly when exposed to fire.
Operation: Divide the absorbent cotton into four equal parts: the first part is the original absorbent cotton; the second part is first soaked in sodium phosphate solution, taken out, dried and then immersed in alum solution, taken out and allowed to dry. The dried absorbent cotton; the third part is soaked in potassium nitrate solution, taken out, and the dried absorbent cotton; the fourth part is soaked in a cold mixture of 10 ml concentrated nitric acid and 20 ml concentrated sulfuric acid, taken out after about 10 minutes, washed, Dry absorbent cotton.
Clamp the above four pieces of absorbent cotton on the wire, leaving a distance of 5 cm from each other, and then light them one by one. The first part can burn, but not quickly; the second part is not easy to burn; the third part is easy to burn; and the fourth part is extremely easy to burn.
(Twenty-four) Breathing out "fairy energy"
Supplies: pointed glass tubes, alcohol lamps, colored plastic tubes, cotton wool.
Gasoline, liquid soap, glycerin.
Principle: Gasoline vapor can ignite. When gasoline and air are mixed and encounter a fire, they will burn violently and make an explosion sound.
Operation: A layer of colored plastic tube is wrapped around a 20 cm long pointed glass tube, and a cotton ball saturated with gasoline is placed inside the tube. Hold the pointed tube against the flame of the alcohol lamp and blow air toward the other end of the glass tube. When the air comes out of the pointed tube, it burns when it encounters fire. Leave the flame and keep burning. If the force of blowing air into the glass tube is slightly stronger, the flame can be 4 to 5 cm away from the tip and appear a bright blue flame, which is very beautiful.
At this time, immerse the tip of the glass tube in soap solution dripping with a small amount of glycerol. After taking it out, blow air into the other end of the glass tube. When a series of soap bubbles appear in the air, use a burning alcohol cotton ball to light each soap bubble, and a series of slight explosions and fireballs will emit, which is very interesting.
(Twenty-five) Fire Extinguishing Painting
Supplies: 100 ml beaker, writing brush, brush, glass rod, glass plate, color picture.
Concentrated borax solution, saturated alum solution, gunpowder cotton, acetone, aluminum powder.
Principle: After the picture is treated with borax and alum solutions, there will be a protective layer on the picture that is not easy to burn. Gunpowder cotton burns quickly, so the picture will not burn.
Operation: Take a color picture, use a brush to apply a layer of borax solution on the picture, dry it and then apply a layer of alum solution, let it dry again and set aside.
Put the gunpowder cotton in a small beaker, add acetone and aluminum powder, and mix thoroughly. Then brush the acetone-thick liquid with gunpowder cotton on the glass plate, and the brushed area is slightly larger than the picture. Repeat 3 to 4 times, peel off and stick to the picture after drying. At this time, use a match to light the gunpowder cotton. When the gunpowder cotton burns out quickly, a beautiful picture appears in front of you.
(26) A fire that cannot burn paper
Supplies: evaporating dish, glass rod, tweezers, paper.
Carbon disulfide, carbon tetrachloride.
Principle: Carbon disulfide is an easily flammable liquid, but carbon tetrachloride cannot burn. Carbon disulfide burns to produce carbon dioxide and sulfur dioxide while releasing heat.
Because there is carbon tetrachloride in it, a lot of heat is taken away when the carbon tetrachloride volatilizes in large quantities, so the temperature of the flame is lowered and cannot reach the ignition point of the paper.
Operation: Pour 6 ml of carbon disulfide and 16 ml of carbon tetrachloride into the evaporating dish and stir evenly. When lit with fire, a light blue flame can be seen. At this time, a piece of ordinary paper was held with tweezers and placed on the flame, but the paper did not burn.
(Twenty-seven) Fire can write and draw
Supplies: two pieces of white paper, brush, pin, incense, alcohol lamp.
30% potassium nitrate solution, 3 mol/L sulfuric acid.
Principle: When potassium nitrate is heated, it decomposes into oxygen, causing the paper to burn. However, since the heat generated during combustion is not large, paper without potassium nitrate coating will not burn.
3 mol/L dilute sulfuric acid turns into concentrated sulfuric acid due to evaporation of water during baking. Concentrated sulfuric acid has dehydrating properties, causing the paper to carbonize and reveal the painting.
Operation:
1. Use a brush dipped in 30% potassium nitrate solution to write on white paper. The words should be large, the strokes should be simple, and the handwriting should be connected together at the starting point. Poke a small hole with a pin to mark, then let dry.
During the performance, incense is used to light the pinhole of each character, so that the fire follows the strokes to write hollow characters.
2. Use a clean brush dipped in sulfuric acid to draw on white paper. After drying in the shade, no traces of the drawing will be visible. During the performance, the white paper is carefully placed on the fire to bake, and the ink strokes gradually appear.
(Twenty-eight) Dripping water makes smoke
Supplies: mortar, crucible, dropper.
Iodine tablets, aluminum powder.
Principle: Iodine and aluminum do not react at room temperature. The reaction occurs immediately after adding the water catalyst. The heat released by the reaction turns the water into water vapor, which, together with iodine vapor and white aluminum iodide, forms a large amount of orange smoke. The smoke is mixed with the beautiful purple vapor of sublimated iodine.
Operation: Take 3 grams of iodine tablets and grind them finely in a dry mortar, then add 0.2 grams of aluminum powder. After mixing them evenly, move them into a crucible and pile them into a mound, making a small pit on the top of the mound. Use a dropper to put 1 to 2 drops of water into the small pit. Iodine and aluminum react violently immediately, producing light and heat while producing thick brown smoke mixed with beautiful purple iodine vapor.
(Twenty-nine) Strong Smoke in the Cup
Supplies: 600 ml beaker, small measuring cylinder, dropper, evaporating dish.
Sand, concentrated sulfuric acid (density 1.84 g/ml), concentrated nitric acid (density 1.4 g/ml), turpentine.
Principle: The mixture of concentrated nitric acid and concentrated sulfuric acid has a strong oxidizing effect. Turpentine is flammable. When it comes into contact with the mixed acid, it is oxidized and releases a lot of heat, causing the turpentine to burn. However, the combustion is not complete and a large amount of carbon is precipitated to form black smoke.
Operation: Place 1 cm thick fine sand at the bottom of the 600 ml beaker. Take an evaporating dish, pour 5 ml of concentrated nitric acid and 5 ml of concentrated sulfuric acid into the evaporating dish, shake gently to mix evenly, and then place the evaporating dish on the sand in the beaker. Use a dropper to absorb a small amount of turpentine and add it drop by drop into the mixed acid, one drop at a time and a puff of smoke.