Funny chemistry stories that will make you fall in love with chemistry
1. Old new seal
There is a batch of ancient paintings that have become grayish yellow and dull, but the seals on them are bright red, like new ones. What is the reason?
After careful research and scientific determination, archaeologists found that most of the pigments used in painting were lead white, which is prone to chemical reactions over time to generate new oxides. The sesame oil is made by stirring, and it is not easy to react chemically in the air, so it maintains the original ruddy and bright color. The chemical composition of cinnabar is mercury sulfide. The chemical properties of mercury sulfide are very stable. It will not change color after long-term exposure to sunlight, and it is resistant to acid and alkali. Because of this, it is used as a pigment.
Some paper will turn yellow after a long time. This is because there are still some impurities inside the paper that have not been removed. After a long time, it will change due to the action of air and sunlight, making the paper gradually yellow and easy to rupture. This can be prevented if the pulp can be bleached with oxygen or bleaching powder when the paper is made. In order to make the paper easily absorb the ink and prevent the ink from dissolving during writing or printing, you can add appropriate glue, such as animal glue, alum, rosin, etc. If you want to make the surface of the paper smooth and write on both sides, you need to add some fillers such as starch, calcium carbonate, talc, kaolin, etc. to fill the gaps between the cellulose, thereby preventing the ink from melting.
2. Pure blue ink and blue-black ink
Looking at the homework we wrote before, we found that some handwritings are blurred, while others are clear. Why is there such a big difference between the handwritings of the same period? It turned out that the unclear handwriting was written in pure blue ink. As time goes by, it will be oxidized, the color will gradually become lighter, or even disappear completely; and this kind of clear writing is written in blue-black ink. After the blue-black ink is oxidized , can gradually generate a chemical substance that never fades – black iron tannate, so the handwriting is relatively clear.
Typically, blue-black inks also incorporate soluble blue organic dyes, sulfuric acid, phenol, glycerin, and fragrances. The addition of sulfuric acid is to keep the ink acidic and prevent the ink from precipitation; phenol, commonly known as carbolic acid, is a well-known preservative, which can sterilize and prevent the ink from rotting and smelling; the chemical composition of glycerin is glycerol, which is a commonly used antifreeze agent , After adding glycerin, the freezing point of water can be greatly reduced, so that the ink is not easy to freeze in winter; as for adding spices, it makes the ink fragrant and pleasant.
3. Find a "coat" for the book
A new book was published at the beginning of the school year. Yangyang used kraft paper while other students used plain paper. After a period of time, only Yangyang’s book cover was intact.
It turns out that the wood fiber used in making kraft paper is relatively long, and when cooking wood, it is treated with caustic soda and sulfide alkali chemicals, so that the chemical effect they play is relatively relaxed, and the original strength of the wood fiber is damaged. It is relatively small, so the paper made of this pulp is closely related to the fibers, so the kraft paper is very strong.
4. Ballpoint pen or ballpoint pen
Immediately after the end of World War II, Americans were still indulging in the triumph of the atomic bomb destroying Japan. A businessman took the opportunity to sell a ballpoint pen, saying that the pen contained precious ‘atomic ink’. Back it up enough to last a lifetime.
Because people have a sense of mystery about the atomic bomb and are eager to know about it, they are rushing to buy this novelty pen. So people call ballpoint pens ballpoint pens. Ballpoint pens are used for a long time, because the ink is relatively viscous, and it is not easy to flow out in large quantities. In addition, the gap between the top of the ballpoint pen and the steel ball is much thinner than the water outlet gap on the tip of the fountain pen. The water flow of the fountain pen is small, so it takes a long time.
5. Four Color Ball Stamps
In 1824, Wheeler had just returned to Germany from Sweden and was busy studying ammonium cyanate. He wanted to slowly evaporate the solution to dryness to obtain crystals, but the evaporation process was too slow, but eventually a colorless needle-like crystal was obtained. , Later he studied this crystal, and after careful analysis, he found that it was urea. To this end, a meaningful commemorative stamp is issued, and four molecular mold balls of black, red, blue and gray are used to represent the C, O, N, and H atoms of urea, respectively.
When ammonium cyanate is heated, it will decompose into ammonia and cyanic acid, and cyanic acid will become isocyanic acid. When isocyanic acid and ammonia recombine, it becomes urea. Urea is a neutral fertilizer that has no effect on the soil and is suitable for various soils and plants. It is a high-quality and efficient nitrogen fertilizer. Urea is hygroscopic, and it can agglomerate after absorbing moisture. Therefore, it should also be protected from moisture during storage and placed in a dry place. Long-term use of urea will not make the soil hard and compact.
6. The "natural enemy" of glass
In life, we find that there are many patterns on some glass or glassware, which are engraved with a substance called hydrofluoric acid. It turns out that hydrofluoric acid is highly corrosive and can easily “eat” glass, making it the “natural enemy” of glass.
The specific operation process is to evenly coat a layer of dense paraffin on the glass, and then use tools to write, draw, and mark the scale on the paraffin, so that the part to be engraved is exposed to the glass, and then apply an appropriate amount of hydrofluoric acid on it. Let it “gnaw” away a layer of the glass. The more hydrofluoric acid is applied, the deeper the glass is, and the less it is applied, the shallower the glass is. In this way, the patterns and patterns that people want appear on the glassware.
7. The "Haunted" Story
We all know that there are no ghosts in the world. The so-called ghost stories are all to scare ourselves, but someone did see the former palace maid near the Forbidden City. Do you know the reason?
In fact, there is a scientific basis for seeing the palace maid in the Forbidden City, because the palace wall is red and contains ferric oxide, and lightning may conduct electricity down. If a palace maid happens to pass by, then the palace wall is equivalent to the function of a video tape. , if there is another lightning coincidence in the future, it may appear again like a video screening.
8. National football - our pride
This table tennis ball, which has brought countless championships and honors to our country, is actually made of cotton. It turned out that the main component of cotton cloth is cellulose, which reacts with the mixture of concentrated sulfuric acid and concentrated nitric acid to form a substance called low-grade nitrocellulose. It turned out that people made a special material, celluloid, using low-density nitrocellulose, and people used it to make table tennis balls.
Celluloid was the first man-made plastic processed from natural raw materials and was widely welcomed by people. It is light in weight, has good elasticity, toughness and mechanical strength, can be made into transparent and opaque products, and is easy to dye into any color. Its disadvantage is that it begins to soften and deform when heated to 80 ° C, and it will cause intense combustion when it encounters fire. Historically, celluloid has been used to manufacture photographic film and motion picture film, and has made outstanding contributions to the development of photography and film art. Because it burns easily, it has now been “retired” and “give way” to other plastics for photographic film. Because celluloid has excellent elasticity, high strength, and is not easy to break, people use it to make table tennis balls.
To this day, celluloid remains the best material for making table tennis balls, and no second material can beat it. Celluloid is easy to process when heated, and people use it to make eyeglass frames. If the spectacle frame is broken, you can repair it yourself: just drop 1-2 drops of acetone at the break and press the break tightly, and it will be repaired after the acetone evaporates.
9. Flash in the dark
A camera with a flash can take pictures even in the dark night, what’s the point?
It turns out that the flashlight is filled with metal—magnesium or aluminum. As long as the magnesium or aluminum is ground into a very fine powder, that is, aluminum powder or magnesium powder, it is very easy to burn, and it can release a lot of heat, which can melt the iron. Install very fine aluminum powder or magnesium powder in the flash, just press the shutter lightly when using it, it will burn up within a few hundredths of a second, emit a dazzling light, and complete the “mission of film sensitivity” in an instant. “. With flash, you can take pictures no matter how dark it is or how dim the light is.
It has now been replaced by electronic flash. At present, electronic flashes are used in optical cameras and digital cameras.