Chapter 148 (1/2)

When all students are in two or two, Hu Zengwu opens the slide and begins experimental teaching.

His style is obviously different from Zhou Yi, and more rigorous. The meticulous standards that each step talks about will not pass by the place that Zhou Yi takes for granted (only his own view).

But at the same time, there are some taste of studying at one glance, which is unlikely to have any impact, which can be said to be not very different from self-study.

This is not his fault, of course. After all, it is very difficult for a wonderful person like zhouchenghuan.

At present, such rhythm as huzengwu is naturally a bit drowsy for Li Zheng, but he still insists on listening hard, mainly to correct some of the improper styles learned by Shiyang.

Just like learning to drive ”neutral sliding”, the speed is moderate, seeing the red light in the distance, hanging to neutral and sliding past with inertia. It is an operation that saves fuel and saves effort without harm. But in the driving license test, this kind of operation is to be deducted.

The old driver of Shiyang is naturally full of such complaints. It should not be fully studied. Maybe an operation is safe in the environment at that time, but it is difficult to say another condition.

As a historian apprentice, Li Zheng is a half wild road. It is not futile to come back to understand the rigor of the study.

One hour of Kung Fu, basic experimental set of the explanation completed.

After 10 minutes rest, huzengwu asked Shen Yiyun to issue experimental questions and materials.

Each person has a roll, plus a small bag of industrial salt mud, and the rest of the reagents needed have been placed on the common experimental table before class.

As soon as they come up to play the real problem, most students are a little flustered, even the theoretical big guy, the previous experiment opportunities are also poor.

A small flat head in the front row glanced at the eye roll and raised his hand and said, ”Mr. Hu, you take us to do it first, right?”

On the stage, huzengwu closed his notebook and shook his head with a face on his face.

”This experiment, the knowledge and skills needed, has been taught to you all in the last class.”

”The experiment took an hour and a half.”

”I will group according to the results, and I will take my small experimental class tomorrow when I reach the standard. If I fail to meet the standards, let a cloud continue to fill you up to the foundation until the standards are met.”

”You are all top-notch people. It must be clear that we are selecting the top of the top, representing Jijing to communicate with the top of the country. Therefore, the big pot meal is not suitable for the present situation.”

”Finally, I would like to emphasize that all the knowledge and skills you need have been taught to you.”

”If you have a strong ability, even if it's the first time you have done the experiment, you can achieve the goal.”

Then he looked up at the eye watch. ”The experiment started, it's three o'clock, and it's four thirty to hand in the report.”

Boom

The students dare to speak but dare not scold.

With the old man, he is just going to teach him the players he likes?

The rest is handed over to this half hanging son?

What is more terrible is that what was taught in the last class?

Some people are confused, others are angry.

Some people, but have gone to the public experimental table to grab reagents.

Li Zheng and Wu took the lead in the first step, respectively, grasping the reagents needed in the first step.

”I'll have 50 ml of sulfuric acid, enough for both of us.” Li Zheng grabbed a 25% sulfuric acid bottle.

Wu Ji picked up the small bottle with pale yellow liquid: ”OK, is 40 ml of sodium hypochlorite enough for me?”

”25 is enough.”

While others were still looking at the roll, they had poured salt mud into the beaker.

Half a minute later, the rest of the staff rushed to the test bench to grab the reagents they had taken.

Huzengwu still has no expression. He pulls the chair to sit down and calls Shen Yiyun next to him and says, ”Li Zheng responds quickly and normally, and Wu number is the number of theories?”

Shen Yiyun quickly turned over the material: ”ninth.”

”Sun LeYang taught?”

Shen Yiyun heard the name, and his voice was soft, and he dared not say more: ”this I don't know. ”

”Since it is attached to Ren Da, it must be sun LeYang.” Huzengwu disdains to smile, ”sunleyang, a person of insufficient level, can not mix scientific research circle, so he has to squeeze into the education circle, and enter the education circle. He is not yet teaching and educating people with old and practical experience. He specializes in research competitions, only knows to make some tricks and tricks, and teaches students to take short-cut solutions to solve problems, and finally, he teaches a bunch of problem making machines to send them to me.”

”Yes Right... ” Shenyiyun has to hear huzengwu spray sun Yueyang almost every month, and has formed a habit of harmony.

According to elder martial brother, it seems to be related to the emotional problems of huzengwu's youth

As for the concrete, no one knows.

After all, this is the absolute death point of huzengwu. I can't mention it.

”It seems that sun Yueyang has been pressing the right question again this year.” After huzengwu scolded enough, he shook his head again. ”A cloud, I don't mean to be embarrassed by his students, that is to say, an objective fact, you don't go out and talk about it.”

”No, no Don't say... ” Shen Yiyun dare not talk more, busy taking out the materials of Shiyang, ”you rarely have the Kung Fu, look at the previous achievements of Shiyang in advance, his father just sent it.””Well.” Huzengwu took over the material and looked over and said, ”what's the situation with Shiyang?”

”In hospital, President Zhou means that even if he can't come, he tries to keep a seat for him.”

”Well Don't mess up this matter. It's Zhouyi's business to give no quota. I should give you a few points here. ” Hu Zengwu put down the materials and whispered, ”so many parents and people in the system will see this selection. If Shi yanglai doesn't come, he will be sent to the country for decision, who will be responsible for the trouble?”

”Yes, but Shiyang's experimental level, I am sure, he is really very excellent, at least no less than Li Zheng.”

”I know, I believe you.” Huzengwu raised his hand and said, ”don't say anything about it.”

Shen Yiyun frowned slightly. If both heavyweight teachers recommended Shiyang, chemistry will have reason to accept their opinions and break the rules to invite Shiyang to enter the country for a decision. So she also wants to fight for it again, and then she gnaws his teeth: ”Mr. Hu, I can give a report on Shiyang's assessment. You can change it, and then join the name with President Zhou to submit it to the chemical society. It should help Shi Yang to help Shi ”I want to fight for it.”

”Absolutely not.” Huzengwu glared at Shen Yiyun. ”Are you afraid you don't make trouble for yourself? Which student in this room has no family background? Really entangled, find out the end, it is your report, He Zhou Yi shake hands is OK, how do you explain? We just take charge of our own parts, and don't get into trouble. ”

”Good...” Shen Yiyun was unwilling to bow down and couldn't say half a word.

She had planned very well. If she persuaded Zhou Yi and huzengwu to protect the history of the two men, the chemical association would probably approve it, and then, in an exceptional way, called Shiyang into the provincial team.

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

But now, Zhou Yi, although interested, has not seen Shiyang before, and dare not be too resolute.

Huzengwu is wise and self-evident, and he is forbidden to speak for Shiyang again.

This development, this chemical pervert, threatened to go to Prague to show the world to prepare special substances guys I'm afraid it's going to be a hospital for the anus and intestine.

Shenyiyun was a man of light speech after all, and he couldn't say anything more. He only kept up with huzengwu in silence and inspected the experiment together.

Li Zheng, the effort to heat the solvent, has cleared up the experimental ideas in his mind.

Magnesium sulfate heptahydrate was extracted from salt mud.

It is better to extract the necessary things than to extract the impurities.

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

In order to extract magnesium, the salt mud should be acid hydrolyzed to form a solution, and then the unwanted substances in the salt mud should be chlorinated and hydrolyzed to hydroxide, so that they can be precipitated into solid, and then filtered in sequence.

Finally, magnesium sulfate heptahydrate was crystallized with the magnesium left behind.

There are many processes, but the principle is simple.

The core is just a little bit - pH.

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

As long as the theory passes through, we can understand the pH value of each material completely precipitated, and the final result can always be very poor.

But if it is a novice in the experiment, the rate will only look at the steps of the roll surface, and follow the basic knowledge, and will not reflect on each step of response, so as to adjust the pH value carefully.

To make sense of this, Li Zheng can not help looking at Wu Shu and worrying about her.

Wu's progress here is a little slower, and his movements are not so skilled. It seems that there is no bad mending experiment.

Li Zheng then pressed his voice and said softly, ”the pH of iron hydroxide completely precipitated is 3.2, aluminum hydroxide...”

Wu suddenly raised his hand, and did not look at Li Zheng, and said quietly, ”I can myself.”

”But you've just been deducted.” Li Zheng said, ”huzengwu gave a short time, and there is no room for mistakes.”

”I know, then I can do it myself.” Wu numbered, with his head low, stirred the salt mud carefully, and his face was colder than ever, ”and then I am angry.”

Li Zheng saw her, nodded and returned to his experiment.

This guy, also said that Eurostar is too proud of self-esteem.

It's 50 steps, a hundred steps.

At the same time, huzengwu led Shen Yiyun, came and went back and forth to patrol, and would give Shen Yiyun a statement from time to time, and let her record on the book, as if it was deduct the operating points.

There is no guidance beyond that.

Basically clear is the sieve tip into the small class.

Especially when he arrived at Wu Shu, huzengwu stood behind her for a long time, and recorded a lot, as if waiting for her to make more mistakes.

Li Zheng only glanced at this side and passed by.

Under the inspection of the two examiners, it was only a simulation experiment, but it was like the final examination.

Because of the many steps and the density of the experiment, the quieter it is to the back.

In the meantime, some people have made mistakes and asked some salt mud to start again. The probability is due to the relationship between pH value deviation.In the formal examination, 20 points will be deducted from the repeated experiment. If the time problem is considered, the preparation question can almost declare 0 point.

The tense atmosphere lasted for nearly an hour.

What broke the atmosphere was a ”Di” sound.