Xueba couples do not study

Chapter 37 may be reasonable, not sure.

On the last day of the National Day holiday, Lin Sheng took out all the May [-]rds that he kept at home and started to write questions.

Brush text in the morning and write in the afternoon.With both arts and sciences, it is the best choice for academic masters.

Now whether it is a senior high school student of A high school or a high school high school student of E high school, he has already chosen to study literature or theory.They usually review another comprehensive subject after they have mastered the comprehensive subject of their choice.

Even He Yang, who is known as a top student in A high school, is the same. He will not read the comprehensive essay until he has completed all the comprehensive questions.

If you think of the comprehensive arts and sciences as a whole, half of the average people will score [-] points, or even [-] points.

After all, everyone feels that as long as another subject can be passed, nothing will happen afterwards.

He Yang scored seven to three, science seven and arts three.

But Lin Sheng scored [-]-[-], with arts and sciences each taking half.

Now, like a small number of students, she is very confused about the selection of subjects for the second year of high school, and she doesn't know whether to choose essays or rationale.

Her scores in arts and sciences are evenly matched, and they are all outstanding in her age.

It is precisely because she has not yet chosen the comprehensive subjects to be studied in the second year of high school, so she plans to finish all the comprehensive subjects of arts and sciences.

The amount of study is more than twice that of ordinary students, but the time is the same as them.

If you ask other top students if they can study like Lin Sheng, they must shake their heads and say: It's a waste of time.

On the last day of the holiday, Lin Sheng frantically studied the questions. He just finished the questions in the afternoon and went to school after packing up.

It was dusk when we got to school.

As the sun sets, the school is bathed in the rosy clouds of the afterglow. The students walk in twos and threes on the campus. The evening breeze brings the fragrance of flowers and plants, which makes people feel refreshed and happy, and the sunset is infinitely better.

Most of the students have already come to the classroom, except for some people who are strolling around the campus cup.

"Sheng, how to do this question."

Lin Sheng came to the classroom, just as he put down his schoolbag, he heard Xiao Yan not far away calling him.

She looked at Xiao Yan's face that was about to cry, sighed on the spot, and then came to her seat, looked at the test paper left by the chemistry teacher on the desk, and said, "Which question?"

"This one," Xiao Yan pointed to the last big question, looked up at Lin Sheng and said, "It's so difficult."

Lin Sheng looked in the direction of Xiao Yan's finger. The difficulty of this question was considered medium. Besides, Xiao Yan didn't like science very much, so she found it difficult.

When 12.8g of copper sheet reacts with nitric acid of a certain concentration, the volume of gas generated is 4.48L under standard conditions.The chemical equation for the reaction of copper and nitric acid is:

Cu+4HNO3（浓）=Cu（NO3）2+2NO2↑+2H2O 3Cu+8HNO3（稀）=3Cu（NO3）2+2NO↑+4H2O
Try to calculate:
(1) The amount of reduced nitric acid
(2) The amount of each component in 4.48L gas.
"For the first question, first assume that the average molecular formula of the gas is NOx, the amount of the reduced nitric acid is y, and the amount of the gas generated under the standard condition is 4.48L/22.4L/mol=0.2mol, the gas molecule and The relational formula of the reduced nitric acid is HNO3—Nox, substituting the previous data, we get y=0.2mol.”

While speaking, Lin Sheng picked up the pencil that Xiao Yan put in the pencil case on the desk, and began to write on the back of the last chemistry test paper.

"So, the amount of species of nitric acid that is reduced is 0.2 mol"

"The second question, in the reaction between copper and nitric acid, copper loses electrons as a reducing agent, nitric acid gains electrons as an oxidant, and the number of electrons gained and lost in the oxidation-reduction reaction is equal. Using electron conservation, set up equations to get NO, The amount of substance in NO2."

“铜的物质的量为12.8g/64g/mol=0.2mol，则0.2molCu变成Cu2+失去的电子为0.2mol×2=0.4mol。”

"Assume that the amount of the substance that generates NO is mmol, the amount of the substance of NO2 is nmol, and the amount of the substance of the mixed gas is 0.2mol, that is, m+n=0.2."

"From the equal number of electrons gained and lost in the oxidation-reduction reaction: 3m+n=0.4, the solution of the series of equations is m=0.1mol, n=0.1mol."

"The answer is that NO is 4.48mol in 0.1L gas, and the amount of NO2 is 0.1mol."

"Understood?" Lin Sheng put down the pencil, looked at Xiao Yan's frowning expression, and said, "I'll explain it again."

After repeating it again, Xiao Yan understood the answer to this question.

After Xiao Yan finished writing this question, she lay down on the table, as if she had used all her strength to write the question just now.

She looked at the back of the last chemistry test paper that Lin Sheng used as a draft. The handwriting on it was very clear, and every step was very detailed. Thinking that there was still a year left for the sophomore class, she said:

"Sheng, do you plan to study theory in the future?"

Lin Sheng didn't answer immediately, she lowered her head to think, then raised her head to look at the sky outside the classroom window, and said after a while:
"Maybe I can learn, I'm not sure."

　The above questions were found from the Internet. I think the difficulty level should be medium. Please don't talk about this question.Reader group number (qq group): 1050344939
　　
　
(End of this chapter)