"The water is coming!"
With a shout. But I saw several classmates guarding a classmate who was wearing only underpants and was running over quickly.
Li Zhen nodded to the classmate: "Thank you for your hard work."
Then he took the bottle of deep well water, poured the water into a beaker, and placed the beaker filled with well water in a basin filled with saltpeter:
"Saltpeter is mainly composed of nitrate, and its chemical name is also called potassium nitrate. In fact, after being mixed with ammonia, it will become ammonium nitrate... Mainly talking about saltpeter. Saltpeter is easily soluble in water. The reason why it keeps you going The reason for stirring is because the saltpeter will continuously absorb heat from the water as it dissolves in the water. If the temperature of the cold water in this basin is 15 degrees, then after your constant stirring now, it will be close to zero."
Listening to what Li Zhen said, Qi Denming, who was sweating profusely, reached out to touch the water in the basin. As soon as he reached out, he quickly retracted his hand and shouted in surprise: "It's so cold. Really, really." It’s cooling down. It’s cooling down.”
"I'll touch it too."
"Don't squeeze, I want to touch you too."
"Don't touch it. Your body temperature will increase the temperature of the water. Don't destroy the experiment." Xu Shenxue yelled.
The excited students immediately retreated angrily, and then Xu Shenxue also touched his hand in the water and shouted in surprise: "Hey, it's really cold. Is it already 0 degrees?"
Qi Denming asked Li Zhen again: "If you had known that adding saltpeter to the water would lower the water temperature, why did you bother to get deep well water and get a new cup and put it in this basin?"
Li Zhen said: "While you are constantly stirring, although a large amount of saltpeter is dissolved and the water temperature is lowered, it is also constantly destroying the equilibrium state among the water molecules. It requires more pressure, so it is not easy to condense. Ice. In fact, even if the water in this basin freezes, it is not drinkable. So, if we compare this basin to... a closed container that can cool down. Then the cup of well water in the basin , is what really turns into ice.”
"Why?"
"The temperature of the water in the basin has become extremely low. It will be transferred to the deep well water in the beaker through this beaker, thus continuing to reduce the temperature of the deep well water. The temperature of the deep well water will continue to pass, and when it reaches the freezing point, it will freeze. "
"What should we do now? Keep stirring?"
Zyden asked clearly.
Li Zhen smiled and shook his head: "No need. It has fully absorbed the heat. Now you only need to cover the mouth of the beaker with paper or plastic. Then cover the basin with a wooden board and place a quilt on the wooden board. , cover it for 30-60 minutes, open it, and the water in the beaker will complete the freezing process."
"Huh? Why do you need to cover the beaker with plastic paper?"
"Prevent the temperature from escaping in the cup. A constant low temperature needs to be maintained in the beaker."
"Then why do you need to cover the basin with a quilt? Didn't you say it will freeze? If you cover it with a quilt, doesn't it warm the water?"
Li Zhen chuckled, did not answer the question, and left Youyou. Telling them the principles is far more useful than telling them some methods.
Maybe the freezing of supersaturated sodium acetate solution is magic. But in fact, understanding the process of slow freezing of nitrate would be more useful for their pioneering thinking in chemistry.
After Li Zhen left, the chemistry teacher angrily slapped the student who asked the question on the head: "You are ignorant and incompetent, don't talk too much, no one will treat you as a mute."
The student looked aggrieved: "What did I say?"
"You unlearned thing, you put a quilt on this basin and... you even warmed the water?"
The student said sincerely: "I really think Li Zhen is wrong about this. That's right. The temperature in this basin is already so low. You still have to put a quilt on it to keep it warm. Isn't this completely opposite?"
"You...you...you unlearned thing!"
The chemistry teacher was so angry that he almost vomited blood: "Why did I teach you such a thing?"
"Teacher, am I right?"
"Ha ha ha ha."
The surrounding students laughed wildly, and at first they thought this classmate was joking. At this moment, seeing that he hadn't reacted yet, they all felt that they had gotten a kick out of it.
Thinking about it carefully, there seems to be nothing wrong with it. If you cover the water with a quilt, wouldn't it make you warm? If the ice is covered with quilts, won't it be warmed? Hmm... It seems to make sense.
Some students brought their own quilts to cover the basin. A group of teachers and students stood aside and waited anxiously.
Xu Shenxue kept frowning: "Is the time up?"
He wants to see the results more than anyone else.
"Principal, it's only ten minutes."
"Why does time pass so slowly?"
“…”
"Is it time yet?"
"Only twenty minutes."
“…”
"Half an hour is up."
"Quickly, lift off the quilt."
Everyone in the chemistry laboratory gathered around. When the quilt was lifted, they only saw white light smoke coming out of the basin. That's a chill.
As the quilt was lifted, the temperature in the entire laboratory seemed to have dropped. I wonder if it was a psychological effect.
But in the center of the basin, in the beaker, there was a cup of deep well water half an hour ago, but now it had all solidified into a cup full of ice. The ice is constantly blowing cold air, and the smoke is curling up.
"ah!"
"It's really freezing!"
"This... this is edible ice."
"It's just autumn, the weather is so hot, ice that only appears in winter actually appears?"
"Saltpeter... isn't that what you use to make bombs? It can actually make water freeze."
"I seem to have learned an amazing science. This... I will be happy in the summer from now on."
"Oh, Li Zhen is indeed Li Zhen, nothing can be difficult for him."
“…”
Xu Shenxue reached out and touched the glass of ice, only to feel a bone-chilling coldness. This was real ice. He reached out and touched the water in the basin again. The water in the basin was still at the same temperature and had not changed. I couldn't help but be full of doubts, as if I had figured something out, and as if I had overlooked something.
His eyes became solemn, and he immediately said loudly: "Make today's story into a book. Write down in detail the method of freezing a supersaturated solution of sodium acetate and the freezing of saltpeter. Write down everything Li Zhen said. Principle, every word is written in detail. When printed, every student in the chemistry department of our school must have a copy."
"Yes principal."
"Of course, I have to ask Li Zhen for advice. This is his patent."
"Yes principal."
“…”
After walking out of the teaching building, Xu Shenxue felt a little depressed. Why did Li Zhen have such powerful knowledge
"As Qian Mao said, putting Li Zhen in university for six years is really... a waste of six years."
"Oh, but how can I help him? He never asks me for anything, and he never talks about his future ideas."
"The phoenix fell in the henhouse, Li Zhen, Li Zhen, you should fly to a wider sky."
Xu Shenxue's heart was filled with weird thoughts, and he felt more and more that he had wronged that kid Li Zhen...
In a separate dormitory, Qi Lengzi ran over from the teaching building in great surprise: "Hahaha, it's really frozen. You are so awesome."
Li Zhen, who was reading a book, smiled and said, "It's nothing amazing."
"It's amazing. How do you know this? Who taught you these things?"
Li Zhen's whole body suddenly shook, and the book in his hand fell to the ground.
His eyes were full of shock and confusion, and he murmured sadly:
"Yes, how do I know? Who taught me? Where did I learn these things?"
"Did a very important person teach me? Who is she? Who is she?"
Suddenly, with a pain in his heart, Li Zhen quickly took out the piece of paper in his arms and kept muttering: "Zhang Zhi... Zhang Zhi. Why am I so afraid that I will forget these two words."
"Qi Lunzi."
"What are you doing?"
"Help me find a needle."
"What are you doing?"
“…”
(End of chapter)