My Identity As A Schoolmaster Has Been Exposed

Chapter 193

During the evening self-study, the whole school was quiet, and the classroom in Class 25 was also very quiet. Of course, some students were talking from time to time.

But this is not whispering, but discussing issues, they never waste any time doing boring things.

In this class, even if it is really noisy, no teacher will take care of the discipline, because they are too conscious, because each of them has a goal in their heart.

Lin Mengjiao looked at the workbook, but at the end she couldn’t figure it out, so she asked Xu Cong for help: “Xu Cong, tell me about chemical oxidation and reduction, right?”

Xu Cong stretched out, thought about it, and then said, “Okay…”

“Wait a minute, let me think about how to tell you systematically.”

Xu Cong knows that Lin Mengjiao’s previous foundation is not good, and this time I have the opportunity to tell her systematically.

“Redox reaction balance, the purpose of this piece of feedback to the test paper is the test and process questions.”

“The exam must be taken!” Xu Cong began to analyze it for her.

Lin Mengjiao nodded, agreeing very much with his point of view: “Hmm! Yes! I looked at a few questions, and I was confused.”

Xu Cong glanced at her questions, did not pay too much attention to it, and continued: “These two types of questions will be balanced by equations.”

“Let’s talk about simple balances first. Here we use the conservation of gain and loss electrons, which is basically divided into two steps. The first step is the conservation of charge.”

While Xu Cong was talking, many students around him began to look around.

When Xu Cong finished speaking and raised his head, these students looked at Xu Cong and blinked his eyes.

Xu Cong looked at them, somewhat puzzled: “???”

Lin Mengjiao looked down at the methods Xu Cong said, and was answering the questions seriously.

Title: Cu₂S+HNO₃(thin)→Cu(NO₃)₂+H₂SO₄+NO₁+H₂O

She started to analyze this question according to the fourth method mentioned by Xu Cong, and finally Lin Mengjiao really answered it.

“Look at it, is it 3, 22, 6, 3, 10, 8!”

Xu Cong looked down at the question pointed by her finger, smiled and nodded.

“- Click to pass, you can consolidate and practice.” Xu Cong said.

Lin Mengjiao was very happy at the moment, because she solved another type of problem and gained a lot of knowledge. She replied very happily: “Okay!”

Then Xu Cong stopped paying attention to her, and continued to swipe his mobile phone with his head down.

Before long, Lin Mengjiao felt that she had mastered it well, and she didn’t bother Xu Cong, so she continued to look at her own chemistry problems.

Girls have a relatively weak understanding of chemistry. In this respect, they are indeed not as good as boys. In addition, because of their poor foundation, Lin Mengjiao is also a little strenuous when doing chemistry problems.

Xu Cong glanced at her at this time, and she happened to be struggling with the question, so she asked: “What’s wrong, after watching for so long, haven’t this multiple-choice question been done?”

Lin Mengjiao glanced at Xu Cong and muttered, “It’s a bit ambiguous, so…”

Xu Cong naturally understood what she meant, so he reached out and knocked Lin Mengjiao’s head.

“Don’t be ambiguous, let me teach you!”

Lin Mengjiao immediately hugged her head and murmured resistance: “Now in the classroom, you are too much.”

Xu Cong smiled unconsciously when he looked at her cute look.

For novices like Lin Mengjiao, Xu Cong is still happy to teach.

If you change to someone else, he will refute you, because his own thinking and learning methods are deeply ingrained, not to mention that some of them will even make a mistake.

Or, for the sake of face, become a master of leverage!

After all, everyone has good grades and can come up with answers. My method is very good. Why should I listen to you?

How simple is yours, anyway, the answer is right, that’s it!

Xu Cong looks at the question. The laboratory uses concentrated hydrochloric acid and manganese dioxide to produce chlorine. Which of the following related statements is correct is (the gas volume is measured under the standard) ()

A. If 0.4mol HCl is provided and Mn02 is excessive, 4.48L of chlorine gas can be produced

B. If 0.4mol HCl is provided and Mn02 is excessive, the number of transfer points must be 0.1mol

C. If 0.4molHCI participates in the reaction, 2.24L of chlorine can be produced

D. If 0.4mol HCI is chlorinated, 2.24L of chlorine can be produced

At this time, under the question, Lin Mengjiao had already listed the chemical formula, but she would not analyze it anymore, or that she could not fully understand the point of the question.

After reading the question, Xu Cong was unambiguous and said directly to her: “Hydrochloric acid produces chlorine gas. It also shows acidity and reducibility. Like this acid, what is particularly annoying is that in any equation for the production of chlorine, this hydrochloric acid There must be a strong word at the back!”

“There is one word missing from your equation. Remember, concentrated hydrochloric acid. In other words, if it is not concentrated, it will not react.”

“Let’s look at the options, A and B. Here are the offers. Remember, this offer means that it will not respond if it reflects. What does it mean?”

Lin Mengjiao replied, “If you provide so much, you don’t necessarily need so much!”

Seeing that she still knows how to lose, Xu Cong nodded and continued: “Yes, the actual consumption must be less than 0.4 mol, so the generated chlorine must also be less than 0.1 mol!”

“Look at the CD again, this side consumes 0.4mol”

At this time, Lin Mengjiao was raised a little by Xu Cong, excited, and immediately said: “So it really consumes 0.4mol in total!”

Xu Cong: “Yes! So it is really 0.1mol!”

“Okay, I’m finished watching this side!”

“Let’s enter the real choice.”

Real choice?

Lin Mengjiao:???”

What do you mean? She looked blank.

Xu Cong smiled and said, “I have explained to you very clearly above, the relationship between supply and consumption!”

“Look at the multiple-choice questions, but if you provide it, you can make it later, get it, and you can get it. Don’t look at it, just exclude it.”

This is the experience of Xu Cong, from the experience of a veteran.

Lin Mengjiao hadn’t experienced it before, so she was naturally puzzled, so she asked, “Why?”

Xu Cong pointed to the title and said: “It can’t be counted at all, forget it? You see, it must be less than this value, it can’t be counted.”

Lin Mengjiao slapped her forehead and immediately understood.

“I see!”

For a Xiaobai like Lin Mengjiao, once she gets the hang of it, she understands it quickly, because she is not affected by other problem-solving methods!

Xu Cong continued: “I’m watching C and participating in the reaction. How much do I get?”

Lin Mengjiao blurted out: “0.1mol!

Xu Cong continued to ask: “So what?”

Lin Mengjiao said with some uncertainty: “So choose C?”

“Yes.” Xu Cong affirmed her answer.

Xu Cong continued to analyze this type of topic for her: “This is called thickening and thinning without reaction. Provide a number, then you can only calculate a maximum value, so the specific number can’t be calculated. Can you understand?”

Lin Mengjiao nodded: “Yes!”

Xu Cong solemnly said: “In this case, many calculation problems are not calculation problems!”

Lin Mengjiao saw him say this, but she couldn’t do it anymore, with a question mark on her face: “???”

Calculation questions, not calculation questions?

This is chemistry, it needs calculation! Why is it not a calculation problem.