After all the students formed a circle, Hu Zengwu opened the slides and began experimental teaching.

His style is obviously different from Zhou Yi's. It is more rigorous. Every step is meticulous and standard. Unlike Zhou Yi, he does not skimp on things that are taken for granted (only in his own opinion).

But at the same time, it also feels like studying in a rigid manner, and it is unlikely to have any impact. It can be said that it is not much different from self-study.

This is of course not his fault. After all, a wonderful person like Zhou Chenghuan is so rare.

Li Zheng was naturally a little sleepy to Hu Zengwu's rhythm at the moment, but he still insisted on listening, mainly to correct some unhealthy habits learned from Shi Yang.

Just like "gliding in neutral" when learning to drive, at a medium speed, when you see a red light in the distance, put it into neutral and use inertia to coast over. This is a fuel-saving, labor-saving and harmless operation, but in the driving license test, this operation is

Points will be deducted.

An experienced driver like Shi Yang is naturally full of tricks like this and shouldn't learn them all. Maybe a certain operation is safe in the environment at that time, but it's hard to say if the conditions are different.

As an apprentice of the Shi Sect, Li Zheng was considered half a wild boy. It was not in vain for him to come back and understand the rigor of scholarship again.

In one hour, the basic experimental routine was explained.

After a 10-minute rest, Hu Zengwu asked Shen Yiyun to distribute the experimental questions and materials.

Each person has a paper, plus a small bag of industrial salt mud, and the rest of the required reagents have been placed on the shared laboratory table before class.

Most of the students were a little panicked when they started to play real questions. Even the theoretical experts had very few experimental opportunities in the past.

A young boy with a crew cut in the front row glanced at the paper and raised his hand: "Teacher Hu, can you take us through it first?"

On the stage, Hu Zengwu closed his notebook and shook his head with a straight face.

"This experiment requires all the knowledge and skills that were taught to you in the last class."

"The experiment lasts one and a half hours."

"I will divide them into groups based on the results. Those who meet the standard will attend my small experimental class tomorrow, and those who do not meet the standard will have Yiyun continue to provide you with the basics until you meet the standard."

"You are all top leaders, and you must also know that we are selecting the top of the top to represent Jijing in communicating with top leaders across the country. Therefore, big pot rice is not suitable for the current situation."

"Finally, I emphasize once again that all the knowledge and skills you need have been taught to you."

"If your abilities are outstanding enough, even if this is your first time doing an experiment, you can still produce results that meet the standards."

After saying this, he raised his arm and looked at his watch: "The experiment has begun. It is now three o'clock. The report will be submitted before four-thirty."

Rumble…

The students dared to speak out but did not dare to scold.

This old man is only going to teach the players he is optimistic about?

Leave the rest to this half-assed senior?

What’s even more terrifying is——

What was taught in the last class?

Some are confused and some are angry.

Someone has already gone to the public laboratory table to grab reagents.

Li Zheng and Wu Shu were the first to bear the brunt, grabbing the reagents needed for the first step respectively.

"I'll give you 50 ml of sulfuric acid, enough for the two of us." Li Zheng grabbed the sulfuric acid bottle marked with a concentration of 25%.

Wu Shu took advantage of the situation and picked up the vial containing the light yellow liquid: "Okay, will 40 ml of sodium hypochlorite here be enough?"

"25 is enough."

While others were still reading the papers, the two of them had already poured the salt mud into the beaker.

Half a minute later, the rest of the people rushed to the test bench one after another, scrambling to grab the reagents that the two had taken.

Hu Zengwu still had no expression. He pulled up a chair and sat down. He called Shen Yiyun next to him and said, "Li Zheng's quick reaction is normal. What is Wu Shu's theoretical rank?"

Shen Yiyun quickly flipped through the materials: "Ninth."

"Taught by Sun Leyang?"

When Shen Yiyun heard the name, his voice softened and he did not dare to say more: "This... I don't know either."

"Since he is affiliated with Renmin University, he must be Sun Leyang." Hu Zengwu smiled disdainfully, "People like Sun Leyang are not good enough to join the scientific research circle, so they have to squeeze into the education circle. If you want to enter the education circle, just join it. He is not honest yet. I teach and educate people, and specialize in competitions. I only know how to use some weird tricks and teach students to take shortcuts to solve problems. In the end, I taught a bunch of problem-solving machines and sent them to me."

"Yeah... right..." Shen Yiyun hears Hu Zengwu criticize Sun Leyang almost every month, and has already formed a habit of responding.

According to the senior brother, it seems to be related to Hu Zengwu’s emotional problems in his youth...

As for the specifics, no one knows.

After all, this is Hu Zengwu’s absolute Achilles’ heel and should never be mentioned.

"It seems that Sun Leyang got the right question again this year." After Hu Zengwu scolded him enough, he shook his head again, "Yiyun, I don't mean to embarrass his students. I'm just telling you an objective fact. Don't go out and talk nonsense. "

"Don't tell... don't tell..." Shen Yiyun didn't dare to talk more and hurriedly took out Shi Yang's materials, "It's rare that you have time to look at Shi Yang's previous results in advance. His father just sent them."

"Well." Hu Zengwu took the materials and said while looking through them, "How is Shi Yang's situation?"

"He is still hospitalized. What Dean Zhou means is that even if he can't come, we will try our best to secure a place for him."

"Well... don't make any trouble about this matter. It's Zhou Yi's business to give a quota or not. I should get as many points as I want." Hu Zengwu put down the materials and whispered, "This selection, there are so many parents and people in the system. People are watching, Shi Yang didn't even come, so he was sent to the National Judgment, who is responsible for the commotion?"

"Yes, but I am confident of Shi Yang's experimental level. He is really, really outstanding, at least as good as Li Zheng."

"I know, I believe you." Hu Zengwu raised his hand and said, "Don't talk about this matter again."

Shen Yiyun frowned slightly. If the two heavyweight teachers strongly recommended Shi Yang, the Chemistry Society would have reason to accept their opinions and recruit Shi Yang to the national finals. So she wanted to try again, so she gritted her teeth and said: "Hu Teacher, I can produce an evaluation report for Shi Yang. You can revise it, then jointly sign it with Dean Zhou and submit it to the Chemical Society, which should help Shi Yang fight for it."

"Absolutely not." Hu Zengwu glared at Shen Yiyun, "Are you afraid of not causing trouble for yourself? Which student in this room does not have some family background? It really got entangled, and in the end, it was your report, Zhou Yi It's fine if you let go, how do you explain it? We just have to take care of our own part and don't cause trouble."

"Okay..." Shen Yiyun was unwilling to bow his head and did not dare to say a word.

She had planned very clearly. If she persuaded Zhou Yi and Hu Zengwu to protect Shi Yang, the Chemical Association would most likely approve it and make an exception to call Shi Yang into the provincial team.

For this reason, she has already said a lot of good things in front of Zhou Yi.

But now it seems that although Zhou Yi has intentions, he has never met Shi Yang and does not dare to be too determined.

Hu Zengwu acted wisely and forbade himself to speak for Shi Yang again.

If things continue like this, this chemical pervert, who threatens to go to Prague to demonstrate the preparation of special substances to the world... is afraid that the Anorectal Hospital will be destroyed.

After all, Shen Yiyun was so quiet that he couldn't say anything else. He just silently followed Hu Zengwu's footsteps and inspected the experiments together.

On Li Zheng's side, he had already sorted out the experimental ideas in his mind while heating the solvent.

Magnesium sulfate heptahydrate is extracted from salt mud.

Rather than extracting what is needed, it is better to say that it is filtering out unwanted impurities.

After all, in industrial salt mud, in addition to the target element magnesium, there are also various chemical components such as calcium, iron, aluminum, and manganese.

In order to extract "magnesium", the salt mud must first be acidolyzed to make a solution, then the unnecessary things in it must be chlorinated, hydrolyzed into hydroxides, precipitated into solids, and filtered sequentially.

Finally, the remaining magnesium is used to crystallize to produce magnesium sulfate heptahydrate.

There are many processes, but the principle is simple.

The core is only one point - ph value.

In this experiment, each substance to be filtered out will precipitate into a solid at different pH values.

As long as the theory is passed and the ph value of each substance is fully precipitated, the final result will always be quite the same.

But if you are a novice experimenter, you will most likely only read the steps on the page and follow the instructions, and will not think deeply about the reactions in each step to adjust the pH value in detail.

After thinking about this, Li Zheng couldn't help but look at Wu Shu and became worried for her.

Wu Shu's progress here is a little slower, his movements are not that skillful, and it seems that he doesn't do much to make up for the experiment.

Li Zheng then lowered his voice and said softly: "The pH of complete precipitation of ferric hydroxide is 3.2, aluminum hydroxide..."

Wu Shu suddenly raised his hand, without looking at Li Zheng, and said calmly: "I can do it myself."

"But you have already been deducted points just now." Li Zheng said solemnly, "The time given by Hu Zengwu is very short, there is no room for mistakes at all."

"I know, then I can do it myself." Wu Shu lowered his head and carefully stirred the salt mud slurry, his expression grimmer than before, "If you do this again, I will be angry."

Seeing her look, Li Zheng finally nodded and returned his attention to his experiment.

This guy kept saying that Ou Xingzhuo valued self-esteem too much.

It’s true that a smile comes from fifty steps and a hundred steps.

At the same time, Hu Zengwu led Shen Yiyun on patrols back and forth. From time to time, he would tell Shen Yiyun to record it in her notebook, as if he was deducting operational points.

Other than that, there is no guidance.

It’s basically clear that only the top students get into the small class.

Especially when she arrived at Wu Shu's place, Hu Zengwu stood behind her for a long time and took notes, as if waiting for her to make more mistakes.

Instead, Li Zheng only glanced at it and passed by.

Under the inspection of two examiners, it was obviously just a simulation experiment, but it was like a final exam.

Since there are many experimental steps and they are very dense, it becomes quieter towards the back.

During this period, some people kept making mistakes and asked for some salt mud and started over again. Most likely it was because of the deviation in the pH value.

In the regular exam, 20 points will be deducted for re-doing the experiment. Taking into account the time issue, the preparation questions can almost be declared as 0 points.

This tense atmosphere lasted for nearly an hour.
To be continued...