Chapter 132: The essence of chemistry is...

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Li Zheng realized that the paragraph had finished.
So where is the laugh...
"Ah... isn't it funny?" Shen Yiyun scratched his head and smiled, "This is probably a stalk that only people in the chemical institute can understand."
"No, no, it's funny. If I understand the dean and the mentor, I must have laughed."
"For acr, axe, the dean is a real overtime madman. Brother is equivalent to looking for a one hundred step person to report fifty steps."
"Hahaha... This is the case." Li Zheng forcibly smiled, and then said, "The stalk itself is more difficult to get, but the school sister is really interesting to say, you are definitely more beautiful than Huadan."
"Oops..." Shen Yiyun blushed again, "That's... art comes from life~"
Opposite, Shi Yang pinched the dropper, as if to pinch bleeding.
He listened to the same whispers of two mosquitoes.
It feels really wrong.
Isn't this a field that respects chemical strength?
Sister Chemistry, don't be fooled by this guy who looks like a scumbag.
Look at me here, look at me here.
However, Shen Yiyun and Li Zheng became hotter and hotter, and couldn't help performing more jokes in the chemistry academy.
Shi Yang was really intolerable and only said in a deep voice: "Then I started?"
Shen Yiyun heard this remark, and his face, which was originally happy and smiling, was instantly covered with a layer of frost.
"Well, please."
Shi Yang gritted his teeth.
Really changed her face?
No big sister.
I want to use chemical power to save you!
Shi Yang was so cruel that he didn't even see the experimental principles and steps, so he started his performance.
"Preparation and titration of coumarin-3-carboxylic acid, Shi Yang."
He said, unscrewing a dark reagent bottle (salicylic aldehyde), holding the dropper and immersing it into it for a while, then picked up the graduated cylinder and dripped the solution. After repeating it twice quickly, the reagent was screwed on. Bottle, there is no graduated cylinder scale.
"Wait, points are deducted." Shen Yiyun raised his hand and sneered. "Look at the roll noodles-take 2 ml of salicylaldehyde. Do you know how much you have taken?"
"2 ml." Shi Yangmu did not squint, and had unscrewed the second reagent bottle (diethyl malonate),
Shen Yiyun's nose tightened, and he wished to check immediately, killing his arrogance.
But as the second eldest sister of Yan, it's really such a compulsory comparison, and it always looks ashamed.
Although Li Zheng is very observant, he is not strong enough to be able to see this layer, but with curiosity instinct, he walks around to the test bench and stares at the scale on the table.
2ml, not bad...
There was a legend that there was an elder sister who sold sugar, and it was said that "one catch is accurate".
Now, he has witnessed a drop of cobalt god.
At this time, he turned his head to look at the man who drew the reagent.
It seems that the whole person has an invisible chemical gas field.
This man, he is no longer Shi Yang.
He is a cobalt god.
at the same time--
[Student luck detected. 】
【Shi Yang: 27】
[Upper learning limit: 26. 】
【learning……】
【Study Win+0.1……】
【+0.1……】
Li Zheng stared.
He didn't close his eyes anymore. Before absorbing his feet, he didn't close his eyes.
Now, the only reference to the student movement is Li Zheng himself.
Is 4.
And Shi Yang, a dick, is nearly 7 times as lucky.
His experimental talents are really the atmospheric transport required by the times.
Mine, mine, all mine!
Of course, stealing luck or something is just a joke.
For readers, this is learning, brainstorming, and common improvement.
Since the system is clearly learning, the luck of the Cobalt God must not be reduced by this.
Inside and out, the nation's air transport has increased out of thin air, and the good thing is right.
Li Zheng stared at Shi Yang so intently, and returned to Shen Yiyun's side.
"It's really 2ml, it's not bad..." Li Zheng said softly.
"Uh..." Shen Yiyun said hatefully, "This... isn't very difficult, there was a senior brother three years ago... that's fine."
On the side of Shi Yang, as soon as the experiment started, it seemed that he could not hear the person speaking to him. In a blink of an eye, 2.4ml of diethyl malonate and 10ml of absolute ethanol were poured into a 50ml round-bottom flask.
In the middle, there are naturally many tricks and small movements.
For example, when adding absolute ethanol, the cobalt obviously slowed down the speed of addition, and at the same time, the flask was quickly rotated and poured in a circle.
Obviously, this is the intention of the Cobalt God.
But Li Zheng couldn't see through.
Had to lean into the ear of the elder sister: "Why..."
He hadn’t asked any doubts yet, and Shen Yiyun replied: "When the reagent was dropped before, there would inevitably be some stained on the wall of the bottle. He did this in order to use absolute ethanol to wash down all other raw materials on the wall ."
Li Zheng heard it with a "huh".
These small details are impossible to write on the test questions.
Only those who have really done a lot of experiments will naturally develop some habits.
It has just begun, there must be very many such tips.
Cobalt God, show your learning luck.
On the opposite side, after the Cobalt God prepared the solution, put the flask on the oil bath holder and fix it. Afterwards, use a high-precision plastic syringe, take some piperidine, dip the needle into the bottle, and carefully inject it into the solution. yellow.
"Humph..." Shen Yiyun suddenly smiled, but then quickly stopped.
What did she see?
Li Zheng did not know.
I don't even know if I asked.
Well, don't ask, just pretend to understand it and hum.
"Humph."
But the Cobalt God did not pay attention to the two at all, and took another tube of glacial acetic acid, suspended his hands motionlessly on the beaker, fixed in the center for a long time, and then dripped.
Unlike the previous chic movements, these two drops are very cautious, and I must be afraid of getting on the wall of the bottle.
In chemical experiments, the dosage requirements are very strict. In many cases, only one drop, a little more or less, will affect the reaction rate and the amount of reaction. In severe cases, even unexpected strange reactions will occur, which eventually leads to the failure of the experiment.
Take the problem of preparing coumarin, the final output score is as high as 40 points.
For this question, the theoretical output is 2.53 grams.
But that is just theory, there is no loss of output from any one molecule.
In an environment like a university laboratory, under human hand-operated conditions, the yield limit is about 90% of the theoretical output.
Therefore, when scoring, as long as the final yield is higher than 80%, it is a full score, 40 points.
70%, 35 points.
60%, 30 points.
And so on.
Looking at the cobalt who is skilled in placing condenser tubes, Shen Yiyun finally took it seriously: "This kind of question, by the undergraduate standard, as long as the yield reaches 70%, it is considered excellent."
"That's 1.78 grams..." Li Zheng mumbled, "You can get full marks for the competition, and the production rate should be higher than 80%, that is... 2 grams."
"It's basically impossible." Shen Yiyun shook his head confidently. "It's not that it's theoretically impossible. It's just the first person to do it. It's impossible. It can be very good when it reaches 70%. If you have a week, do it a few times. Ten times, constantly fine-tuning the dosage, time and temperature, pursuing the limit, and probably still working out some methods to increase production."
"Dose, time, temperature..." Li Zheng couldn't help saying, "Isn't that alchemy..."
"It really doesn't matter much." Shen Yiyun raised his glasses. "Chemical experiments are essentially the manipulation of molecular activities in the microscopic world, creating the needed substances through the magic of bonds and rings."
"Well..." Li Zheng heard this, and only then felt that she finally touched a threshold of chemistry.
Then look at Shi Yang, who is attentive and attentive, and shows evil smiles.
Li Zheng seems to see the creator of a microcosm.
It turned out that this is where the pleasure of chemistry lies!
Oh shit.
Itchy hands.
I really want to experiment.