"Question 1: A certain amount of absolute alcohol and oxygen are placed in a completely closed container and ignited. The reaction produces carbon dioxide, water vapor and an unknown substance X. Measure the mass of the substance before and after the reaction. Absolute ethanol is 4.6g and 0g, oxygen is 8g and 0g, carbon dioxide is 0, water is 0, substance X is 0g and mg, the value of m is ______, and the molecular formula of substance X is ______.”
(Note: In order to facilitate future teaching, Li Zexuan unified the commonly used units at the front of the four textbooks. However, this is only a written unification. The actual unification will depend on the joint efforts of teachers and students of Yanhuang Academy in the future.)
Although he was prepared for the difficulty of the exam, Wang Ji was a little surprised that the first question was a practical application plus calculation question. Shouldn't he be tested on basic concepts first?
But this question was mainly about the law of conservation of mass during chemical reactions. After a little calculation, he came up with the correct answer.
At this time, he couldn't help but feel lucky in his heart. Fortunately, he also studied new arithmetic. Otherwise, how could he calculate so quickly?
"The second question, put two glass cups A and B on the two plates of the scale. The glass cups contain dilute sulfuric acid with different masses but both contain 9.8g of sulfuric acid. It is known that glass cup A is heavier than glass cup B. Now After putting equal masses of iron and zinc into two glass cups A and B respectively, and the balance remains balanced after the reaction, the maximum mass difference between glass A and glass B before the reaction is ____ or _______."
(Note: Balances have existed in ancient times. They were produced earlier. By the late Spring and Autumn Period, the manufacturing technology of balances and weights had become quite sophisticated. Bamboo slices were used as beams, silk threads were used as handles, and the two ends were hung with Ge. A copper plate. Later, because it was troublesome to weigh heavy objects with a balance, it was changed to "quan", and a balance was used only when weighing small objects)
Although Wang Ji has never seen sulfuric acid and zinc, he still knows their chemical reactions by heart. But why does this question seem more perverted than the previous question? You should also use the knowledge of equations in new arithmetic, right?
Wang Ji's heart suddenly began to gallop. It must be thanks to his research on new mathematics. Otherwise, no matter how familiar he was with the "Chemistry" textbook and how thoroughly he understood it, he would still have to kneel when he encountered this test paper!
However, although Wang Ji had done some research on new arithmetic, he was far from proficient. After solving a problem, he was so tired that he was sweating profusely, as if he had run ten miles.
After finishing the second question, Wang Ji couldn't help but raise his head, glanced at Li Zexuan with a bit of resentment in his eyes, and thought to himself: Do I have any grudge against you? It’s just a question, does it need to be so difficult?
This is not because he is being pretentious, but strictly speaking, the question Li Zexuan asked is somewhat "over the top." Moreover, all the test questions are biased towards practical applications. It is basically difficult to get good grades by just reading books!
"Oh, no matter how difficult it is, we still have to fight! We can't lose this bet!"
Although he only stayed at Yanhuang Academy for more than a month, Wang Ji felt that he had completely fallen in love with it. Not only did he like the environmental facilities and fine wine and food here, he also liked the atmosphere of Yanhuang Academy, which was positive and uplifting. An atmosphere of unity and progress!
He doesn't want to leave!
The desire to live, this can be regarded as another kind of desire to live!
The strong desire to survive made Wang Ji's mind clearer than ever before, and his thinking became more active. Although most of the test papers contained questions he had never seen before, he could always find ideas for solving the problems. That's it. After beating all the tests all the way, Wang Ji finally came to the last question with half an hour left before the end of the exam.
This is a question and answer question, "After a mixture of sodium carbonate, sodium bicarbonate, calcium oxide and sodium hydroxide is dissolved in sufficient water and fully reacted, all calcium ions, carbonate ions, and bicarbonate ions in the solution are converted into precipitates , evaporate the water in the reaction vessel to dryness, and finally obtain a white solid. What is the mass of sodium carbonate in the original mixture?"
The sequelae of beating all the tests and performing beyond the ordinary is a headache. After seeing this last big question, Wang Ji felt like his head was going to explode! Because many substances in this question can interact with each other.
In fact, for Li Zexuan, a person with modern higher education, this question is not difficult at all, because it simply involves multi-step reactions and multi-substance cross-reactions (calcium oxide reacts with water to generate calcium hydroxide, calcium hydroxide and can react with sodium carbonate and sodium bicarbonate). As long as you combine multiple chemical reaction formulas into one and balance them to get a total chemical reaction formula, the whole problem will be solved easily without any difficulty. .
But for Wang Ji, a beginner in Chemistry, he obviously does not know this method, so what should we do? He must win this question!
After thinking for a long time, Wang Ji couldn't come up with a very clever or simple method. He gritted his teeth, thought hard, and decided to use the stupidest method to solve this problem, which was to use equations.
"Isn't it just that there are too many unknowns? It doesn't matter, solve it! I don't believe it, I still can't solve it today~!"
Wang Ji felt cruel in his heart.
At the same time, he couldn't help but sigh, is this a "Chemistry" exam or a "Mathematics" exam? In order to calculate, he used three sheets of draft paper!
Fortunately, he used the pencil given by Li Zexuan. If he had used a brush, Wang Ji felt that he wouldn't have to take the exam, and he would be exhausted just polishing the ink~!
"Dang Dang Dang~!"
"Okay, time's up, Mr. Wang, please stop writing~!"
At four o'clock in the afternoon, the gongs and drums of the academy sounded, and Li Zexuan immediately stood up and said.
Wang Ji just finished writing the last word at this time, and he let out a big sigh. Originally, he thought that one and a half hours was more than enough time, but now he didn't even have time to check, so he had to hand in the paper.
"Haha~! Wang Wugong, how did you do in the exam?"
As soon as Wang Ji handed in the paper, Yan Silu immediately asked.
I don't know whether the tone was gloating or concern.
"No, no! We'll talk about other things later. I have a severe headache now, so I have to go back and have a good rest~! Chief Shan, Wen Ji, Kong Gui, I'll take my leave first~!"
Wang Ji frowned, banged his head, stood up and said with a painful look on his face, he had overused his brain in this exam.
"Mr. Wang is not feeling well? Do you want me to call the doctor for you?"
Li Zexuan asked with a worried look on his face. He didn't want to destroy the "genius" Wang Ji just because of a test.
"No need, I just feel a little tired. I should be fine after a nap~!"
Wang Ji waved his hand and said.
………………………
