"Question 1: A certain amount of anhydrous alcohol and oxygen is placed in a completely closed container and ignited, and the reaction produces carbon dioxide, water vapor, and an unknown substance X. The mass of the substance before and after the reaction was measured, the absolute ethanol was 4.6g and 0g, oxygen was 8g and 0g, carbon dioxide was 0g and 4.4g, water was 0g and 5.4g, substance X was 0g and mg, the value of m was ______, and the molecular formula of substance X was ______. ”

(Note, in order to facilitate future teaching, Li Zexuan unified the units at the front of the four textbooks, but this is only a written unity, and the actual unification depends on the joint efforts of teachers and students of Yanhuang Academy in the future)

Although he had prepared for the difficulty of the exam, the first question was such a practical application plus calculation question, which still surprised Wang Ji, shouldn't he test the basic concepts first?

But this question is mainly to test the law of conservation of mass in the process of chemical reactions, and he came up with the correct answer after a little calculation.

At this time, he couldn't help but rejoice in his heart, fortunately, he also studied new arithmetic, otherwise how could he calculate so quickly?

"The second question, on the balance of two plates, put on A, B two glass cups, the glass cup is contained in different quality but contain 9.8g of sulfuric acid of dilute sulfuric acid, it is known that A glass cup is heavier than B glass cup, now A and B two glass cups are respectively put into the same mass of iron and zinc after the end of the reaction, the balance remains balanced, then the maximum mass difference of A and B glass before the reaction is or."

(Note, there was such a thing as a balance, which existed in ancient times, and it was produced earlier, and by the late Spring and Autumn period, the manufacturing technology of balances and weights was quite sophisticated.) The bamboo piece is used as a beam, the silk thread is the button, and a copper plate is hung at both ends. Later, due to the trouble of weighing heavy objects on the balance, it was changed to "Quan", and the balance was used when weighing small objects)

Although Wang Ji has never seen sulfuric acid and zinc, he still memorizes their chemical reactions, but why does this question seem more perverted than the previous one? I think I also used the knowledge of equations in modern arithmetic, right?

Wang Ji's heart suddenly began to gallop, thanks to his research on new arithmetic, otherwise even if he memorized the textbook "Chemistry" and understood it thoroughly, he would have to kneel when he encountered this test paper!

However, although Wang Ji has some research on new arithmetic, he is far from being proficient, and after solving a problem, he is already tired and sweating, just like running ten miles.

After finishing the second question, Wang Ji couldn't help but raise his head, glanced at Li Zexuan with his somewhat resentful eyes, and said in his heart: Does the old man have a grudge against your kid? It's just a question, is it necessary to be so difficult?

This is not that he is hypocritical, but in a strict sense, Li Zexuan's question is somewhat "overclass". Moreover, all the test questions are biased towards practical application, and it is basically difficult to get a good score just by reading books!

"Alas, no matter how difficult it is, you have to fight! You can't afford to lose this gamble! ”

Although he only stayed in Yanhuang Academy for more than a month, Wang Ji felt that he had completely liked it here, not only because he liked the environmental facilities and the food and wine here, but also because he liked the atmosphere of Yanhuang Academy, which was positive and united!

He didn't want to leave!

The desire to survive is another desire to survive!

The strong desire to survive made Wang Ji's mind unprecedentedly clear, and his thinking became active, although most of the question types on the test papers were types of questions that he had never seen before, but he could always find solutions to the problems from them, so he broke through all the way, and when there was still half an hour before the end of the exam, Wang Ji finally came to the last question.

This is a question and answer question, "37.2g of a mixture of sodium carbonate, sodium bicarbonate, calcium oxide and sodium hydroxide, dissolved in sufficient water and fully reacted, the calcium ions, carbonate ions, and bicarbonate ions in the solution are all converted into precipitation, and the water in the reaction vessel is evaporated dry, and finally 39.0g of white solid is obtained, what is the mass of sodium carbonate in the original mixture?" ”

The sequelae of breaking through the hurdles all the way and playing extraordinarily is brain pain, and after seeing this last big question at this moment, Wang Ji feels that his head is going to blow up! Because many of the substances in this question can react with each other.

In fact, for Li Zexuan, a person with modern higher education, this problem is not difficult at all, because it involves nothing more than multi-step reactions and multi-substance cross-reactions (calcium oxide reacts with water to generate calcium hydroxide, calcium hydroxide can react with sodium carbonate, and can also react with sodium bicarbonate).

But for Wang Ji, a beginner in "Chemistry", he obviously doesn't know this method, so what should he do? He's got to get this question done!

After thinking about it for a long time, Wang Ji didn't come up with a very ingenious and simple way, he gritted his teeth, turned his heart sideways, and decided to use the stupidest way to solve this problem, that is, to use the method of equations.

"Isn't there just a little more unknown? It's okay, solution! The old man doesn't believe it, and he can't solve it today~! ”

Wang Ji secretly said ruthlessly in his heart.

At the same time, he couldn't help but sigh, is this the "Chemistry" exam or the "Arithmetic" exam? He used three pieces of scratch paper for the calculation!

Fortunately, he used a pencil given by Li Zexuan, if he used a brush, Wang Ji felt that he didn't have to take the test, and he would be tired to death just grinding ink~!

"Bell~!"

"Okay, it's time, Mr. Wang, please stop writing~!"

At four o'clock, the gongs and drums of the academy sounded, and Li Zexuan immediately got up and said.

Wang Ji just finished writing the last word at this time, he breathed a sigh of relief, originally he thought that an hour and a half was more than enough, but now he didn't even have time to check, so he had to hand in the paper.

"Hehe~! Wang Wugong, how did you do in the exam? ”

As soon as Wang Ji handed in the papers, Yan Silu immediately asked.

I don't know if it's schadenfreude or concern.

"No, no! I'll talk about other things later, the old man has a headache now, and he has to go back to rest~! The mountain chief, Wen Ji, Kong Gui, the old man said goodbye first~! ”

Wang Ji wrinkled his brows, shook his head, stood up and said with a painful face, he used his brain a little too much in this exam.

"Mr. Wang is unwell? Do you want the kid to call you a doctor? ”

Li Zexuan asked with a worried face, he didn't want to ruin Wang Ji, a "genius", because of an exam.

"No need, the old man just feels a little tired, and he should be fine after a good night's sleep~!"

Wang Ji waved his hand.

………………………

The second update!

The third is very late, let's see it tomorrow morning!

(End of chapter)