The Fiery Era: Starting from Longxugou

After regaining his composure, Zhao Shi'an continued working on the problems. Seeing that the student quickly recovered, Hu Chengzhi nodded approvingly.

He set the chemistry exam, which was very basic overall. He had just seen Zhao Shi'an answer the questions very quickly, and as the chemistry teacher and homeroom teacher, he wanted to see how his students performed!

With this in mind, Hu Chengzhi picked up his teacup and sat down to watch intently.

Zhao Shi'an was completely unaffected, even though the chemistry exam included content on organic chemistry and polymer compounds.

The content examined was very basic, such as what is a polymer compound? Give two examples of natural polymer compounds and two examples of artificially synthesized polymers.

It tests your understanding of definitions, just like memorizing classical Chinese poems in language arts.

In less than half an hour, only the impromptu bonus questions remained on the entire exam paper.

Hu Chengzhi's expression became much more serious when he saw that Zhao Shi'an had finished the bonus question so quickly!

Zhao Shi'an glanced at the bonus questions on crude salt purification. High schools in this era did not teach the chemical methods of crude salt purification; they only explained the physical methods of dissolving, filtering, evaporation, and crystallization.

The homeroom teacher's question mentioned two chemical substances: magnesium chloride and calcium chloride.

It was clearly intended that after filtering out the silt, he would use chemical reagents to remove excess magnesium and calcium ions.

This question is somewhat beyond the scope of the textbook, no wonder the teacher reminded him earlier.

However, it is still far inferior to the crude salt purification methods used in modern high school chemistry.

In modern times, it's not so easy to buy coarse salt, and it's expensive, but in this era it's everywhere.

He has a large earthenware jar at home, which is filled with large, yellowish-brown salt blocks. If you don't look closely, you might mistake it for large rock candy!

Nowadays, most families in China use coarse salt.

Coarse salt tastes bitter because it contains a large amount of magnesium chloride and magnesium sulfate. The more magnesium ions there are, the more pronounced the bitterness.

The yellowing is due to the presence of small amounts of mud, sand, iron ions, etc.

The purification of crude salt would be a simple chemical experiment in modern times, but it is a practical method in this era.

Thinking about all this, Zhao Shi'an was also considering refining the coarse salt in his house someday.

From an economic and cost-saving perspective, using alkali directly can remove most of the magnesium ions, and the bitterness after purification will not be too obvious.

In addition, this method can also be used to publish popular science articles, and then earn a fee for the articles.

It's well-known that coarse salt is bitter. Using a small amount of alkali can remove the bitterness, and most people would probably be willing to try it. Of course, it doesn't really matter if you don't try it. Magnesium ions are one of the essential elements for the human body. It's just that the taste isn't very good, which is why Chinese people have been eating coarse salt for decades without being affected. Apart from the bitterness, coarse salt has all the advantages.

After thinking for a while, Zhao Shi'an picked up his pen and began to write.

Hu Chengzhi interpreted Zhao Shi'an's pause as a sign that the student was stumped by the bonus question, and after much contemplation, finally began to write.

After seeing Zhao Shi'an finish writing about dissolution and filtration, Hu Chengzhi nodded slightly, thinking to himself that the student had a good grasp of the textbook knowledge!

Next comes the difficult part. Although many students can remove the impurities mentioned in the question, they end up turning coarse salt into a big mess!

This part is where the student's overall thinking is assessed.

Thinking about all this, Hu Chengzhi looked at it carefully and saw Zhao Shi'an start writing chemical equations. Seeing this, he looked even more attentively.

Zhao Shi'an wrote very quickly, finishing the four chemical equations in no time. He then checked them twice and handed in his paper.

"Teacher, I've finished writing!"

"Good! Let me see, not bad, not bad!"

Hu Chengzhi took the test paper, glanced at it briefly, and nodded to himself. His gaze finally fell on the bonus question he had just set. Seeing Zhao Shi'an's answer, he was extremely satisfied and couldn't help but praise him:

"Good, good! I thought this bonus question would stump you, but you gave such a perfect answer."

First, sodium hydroxide is used to remove magnesium ions, then sodium carbonate is used to remove calcium ions, and finally dilute hydrochloric acid is used to neutralize excess sodium hydroxide and sodium carbonate. No unnecessary substances are introduced throughout the process, which is very comprehensive!

Even high school seniors don't have as comprehensive an understanding as you!

Hu Chengzhi praised Zhao Shi'an's exam paper highly.

Hearing Hu Chengzhi's praise, the teachers in the office also looked over curiously. Considering that the students were present, none of them went over, but they did prick up their ears!

"Teacher, you flatter me. Since it is the purification of crude salt, we must consider the whole picture. We can't introduce new impurities after removing magnesium and calcium ions!"

The first choice should be compounds containing sodium or chlorine. After these compounds react, the remaining sodium and chlorine combine to form a salt, which not only removes impurities but also increases the purity and concentration of the salt!

Zhao Shi'an gave a serious explanation, without deliberately showing off, but simply removing as many impurities as possible based on the information given in the test questions.

"Your idea is excellent! Just from this, it's clear that you have a very solid foundation in chemistry. I'm sure the upcoming test will be a piece of cake for you!"

However, the proper procedures still need to be followed. Once you finish the test and pass, the teacher will personally escort you to the senior year. How about that?

As Hu Chengzhi watched the student write the answers and listened to his problem-solving approach, his eyes lit up.

Combining these two aspects reveals Zhao Shi'an's meticulous logic, clear standards for reagent selection, and standardized equation writing!

It is clear that this student's foundation is far superior to that of most students.

Thinking about all this, Hu Chengzhi began to value Zhao Shi'an even more.

"Thank you, teacher. I promise I won't let you down!"

Hearing the teacher's words, Zhao Shi'an thought to himself that he was in luck. Most teachers like good students, especially those who excel in the subjects they teach, who are even more favored by their teachers.

Hu Chengzhi is the class's chemistry teacher and also the homeroom teacher. If I can answer the extra questions he gives perfectly, it will definitely improve my status in the teacher's eyes. When the teacher helps me communicate and coordinate to skip a grade, I believe he will be more dedicated!

"Studying is for yourself, not for the teacher. Of course, if you get good grades, the teacher will be proud too! Haha!"

Alright, it's getting late, you should go home now! Get some rest at noon, you have another test this afternoon!

Hu Chengzhi was very happy to hear this. He patted Zhao Shi'an on the shoulder and told him to go home early so that he could be well-rested for the afternoon test!

"Teacher, there's still time, let me do another set of biology questions!"

We'll try our best to finish the exam this afternoon, so that we have enough time for you and the teachers to discuss things properly!

Zhao Shi'an expressed his thoughts. He didn't know about the six subjects test and thought that all of them would be tested. Therefore, he wanted to finish writing them all in one day, since the homeroom teacher hadn't mentioned it.

"You have to take another exam? Aren't you tired?"

Hu Chengzhi was very surprised and quickly became concerned.

From the start of math practice until now, almost two hours have passed. Zhao Shi'an has completed three sets of test papers. Although the questions are relatively simple, it is still very tiring to do so many questions in such a short time.

"Teacher, I'm not tired! These questions are all pretty basic. I don't think biology can be too difficult. The sooner I finish, the sooner we can discuss it."

Upon hearing this, Zhao Shi'an smiled and explained that the questions were not even a warm-up, so there was no question of being tired.

"Okay, since you want to continue taking the test, the teacher won't stop you. Answer the questions carefully, and don't rush!"