Group leader of life chemistry: after a semester of research and study, our group completed the research of life chemistry. The specific division of labor is as follows: (1) Chemical experiments in life; (2) Online data collection; (3) data collation; (3) Through this research study, we are more aware of the importance of chemistry in life. Life is inseparable from chemistry. After many experiments, I will find the chemical essence of many phenomena in my life and apply the chemical knowledge I have learned to practice. For example, the oxidation test of apples in the air and the decontamination principle of washing powder. . . In addition, some network materials have been compiled to let us know some chemical phenomena that cannot be tested by ourselves. Draw the following conclusions. In the dim light, a middle-aged man with long hair half closed his eyes, waving a "sword" at random in his right hand and muttering to himself. Suddenly, he seemed to see something, his eyes motionless, staring at the front tightly, and even seemed to stir something. He carefully put the "treasure gourd" around his waist to his mouth and took a sip of "fairy water". As the sword in his hand stabbed out in vain, with a "poof" at the sword, suddenly, deep red blood dripped from the sword. I saw that he said to a mother and daughter who had already been scared to the ground: "Don't be afraid! I have killed the ghost ... "This is a trick to kill ghosts in the air in science and education films that advocates science and opposes superstition. It turned out that he used the chemical reaction FeCl3+3KSCN = Fe(SCN)3+3KCl to cheat money. In fact, chemistry is around us, and there is chemistry everywhere in life. As long as we pay attention, we will gain something. Please see: 1. The same pen uses different kinds of ink, why is it easy to cause blockage? Ink is colloid, and different ink colloid particles have different charges. When two colloids with opposite charges are mixed, the repulsion between colloidal particles with the same charge is reduced due to mutual neutralization, so that they aggregate into large particles, and colloid aggregation causes blockage. Do you know why bananas ripen overnight? Bananas eaten in the north are not ripe on the trees. It turned out that bananas were picked and transported to the north before they were fully ripe. Before selling, put the bananas to be sold in a sealed room and spray a synthetic chemical regulator-ethephon. When ethephon is absorbed by bananas, the banana will release ethylene, which can promote banana ripening. So, the next day, the banana turned yellow and matured. If you have green bananas, green oranges and other immature fruits at home, you can put them in plastic bags with ripe apples and tie them tightly. It will mature in a few days. This is because the fruit itself will release ethylene gas during the ripening process, and the ethylene released by the mature fruit can be used to accelerate ripening and bear fruit. 3. Why are some bricks fired with the same clay blue and some red? When firing bricks and tiles, the green body made of clay is baked, and the iron compound is converted into Fe2O3 to make red bricks and tiles. If cold water is slowly sprayed downwards from the top of the kiln in the later stage of firing, due to the chemical reaction C+H2O = CO+H2, a large amount of CO and H2 will be generated in the kiln, which will reduce red Fe2O3 to black Fe3O4 and FeO, thus making blue tiles. 4. How to wash clothes with washing powder? The component of washing powder is synthetic detergent, and the main component is sodium alkyl sulfonate. According to its molecular structure, it can be divided into two parts, as shown in figure 1: one part is nonpolar hydrophobic group CH3-(CH2)n-, which is lipophilic, and the other part is polar hydrophilic group -SO3Na, which is easily soluble in water. In the washing process, the hydrophobic CH3-(CH2)n part is inserted into the grease in the dirt, while the hydrophilic -SO3Na part extends out of the grease, as shown in Figure 2, so that the grease is surrounded. After friction and vibration, large oil stains are dispersed into small oil beads and separated from clothes. 5. What is a jack-o'-lantern? Have you ever seen a ghost fire? On a summer night, when you walk past a cemetery, you will often see the blue "jack-o'-lantern" around the cemetery and the hooting of owls in the distance, which looks terrible. Some people even say that this is the ghost lamp of Yan Luowang patrol ... but it is not. Human and animal corpses contain a lot of phosphorus, which will turn into phosphine after decay. Phosphine can spontaneously ignite in the air, forming a "ghost fire". In the laboratory, we can make a "jack-o 'lantern". First, white phosphorus and concentrated potassium hydroxide solution are added into a flask. After heating, phosphine bubbles will emerge from the glass nozzle. At this time, cover the window with a black cloth, and you will see a light blue bright circle coming out of the glass nozzle and wandering in the air, just like a "jack-o'-lantern". 6. Why do iron products in life, such as domestic woks, appear rust spots after being washed and placed with water? They are all iron alloys containing a certain amount of carbon. When put together with water, the oil on the surface is washed away, and there is a thin layer of water on the surface, which is a very weak electrolyte, so there is a condition of electrochemical corrosion-electrolyte solution. In this way, countless tiny Fe-C primary cells are formed. Iron as a negative electrode reacts with Fe-2 e- = Fe2+ and with 2 H2O+O2+4e- = 4OH- on the surface of the positive electrode C. The generated Fe2+ and OH- react again to generate Fe(OH)2, which is easily oxidized by O2 to Fe(OH)3: 4fe (OH) 2+2h2o+O2 = 4fe (. 7. How to remove the choking smell of coal cake burning? The choking smell of coal cake combustion is that sulfur-containing coal produces toxic gas SO2, which is strongly irritating. If lime is added to coal, SO2 produced during combustion will react with lime, and Ca (OH) 2+SO2 = caso3+H2O; The generated CaSO3 reacts with O2 again: 2CaSO3+O2 = 2CaSO4. The generation of CaSO4 eliminates the emission of harmful gas SO2, and there is no smell of "coal". 8. What's the matter with "Bitter water with tofu, everything drops"? It turns out that soybean milk is protein's colloid dispersed in water, and there are electrolytes such as MgCl2 in brine. When brine is added to boiled soybean milk, charged ions ionized by MgCl2 neutralize the charges adsorbed by protein colloidal particles, which reduces the repulsive force of the colloids due to the same charges and makes them agglomerate. After coagulation, some colloidal particles and water coagulate to form tofu flower, and then squeeze to form protein. 9. Why are steamed buns soft and porous? Before making steamed bread, you should first "mix flour", that is, mix flour or yeast powder with flour, water and dough, and the yeast inside will multiply rapidly when it meets wet dough. They break down some starch in flour into glucose, carbon dioxide and organic acid lactic acid. After the dough is cooked, steamed bread is made of soda ash and steamed in a steamer. The carbon dioxide generated by the reaction of carbon dioxide and organic acid with soda ash in the dough expands after heating, and finally runs out of the dough, leaving countless small holes on the steamed bread. Steamed buns become bigger and looser. 10. Why did you open the soda bottle? Soda is made by mixing baking soda (sodium bicarbonate) with citric acid, sweetener and food coloring. In a certain proportion in the water. Baking soda reacts with citric acid to produce carbon dioxide gas, but the bottle has been blocked and carbon dioxide is forced to dissolve in water. When the cork is opened, the pressure becomes smaller, and the solubility of carbon dioxide in water becomes smaller, so it escapes from the water, which is why we see bubbles churning. 1 1. Why do you use alum for fritters? The chemical formula of alum is 2kal (SO4) 2. 12h2o. When fried dough sticks are used, they are mixed with baking soda (NaHCO3) in a certain proportion and used as leavening agent. In the process of high-temperature frying, Al3+ and HCO3- undergo double hydrolysis reaction, producing carbon dioxide gas, and making fried dough sticks. The reaction equation is as follows: 6nahco3+2kal (SO4) 2 = 3Na2SO4+K2SO4+2al (OH) 3↓+6CO2 ↑. If you eat too much aluminum in food often, it will accumulate too much in the human body, which will easily affect the function of brain cells, leading to decreased memory and slow thinking. However, people with stomach diseases often eat fried dough sticks, because the aluminum hydroxide produced is the main component of weishuping, which can neutralize excessive gastric acid (hydrochloric acid) produced in the stomach and protect the gastric mucosa. 12. Why is it especially clean to wash dishes with plant ash? In the past, when people washed pot lids, oil drums and dishes, they often grabbed a handful of plant ash and rubbed it first, then washed it with clear water, which was especially clean after washing. It turns out that plant ash contains potassium carbonate, which is hydrolyzed in water to generate hydroxyl ions, which are saponified with oil (higher fatty acid glyceride) to generate water-soluble sodium fatty acid and glycerol, and the oil stains are washed away. 13. How did Mr. Lu Xun read Comrade Fang Zhimin's Letter Without Words? 1935 Comrade Fang Zhimin cleverly escaped from the stupid guard in prison and sent a "wordless letter" to Mr. Lu Xun by client. After receiving it, the clever Mr. Lu Xun found a basin of clear water with a few drops of iodine, then put this "wordless letter" into the water and successfully read the contents of the letter. It turns out that this letter was quietly written by Comrade Fang Zhimin while eating rice soup. There is starch in rice soup, which will turn blue when it meets iodine, while the iodine added by Mr. Lu Xun has iodine, so it will show blue handwriting. These are the dribs and drabs of chemistry around us. In our daily study and life, we should be a conscientious person, use chemistry to explain the phenomena in life, apply chemistry to life, and let chemistry serve our life better.