Ten minutes between classes.

Fan Jing was sitting in her seat, reading with one hand on her chin.

Suddenly a voice came from next to him, "Fan Jing, can you teach me how to do this question?"

I looked up and found that it was Liao Xinpei from the class.

Fan Jing's face turned red suddenly.

Liao Xinpei is a handsome guy who plays basketball well in his class. Fan Jing often sits next to the window of the classroom to watch him play basketball. There are many people who like Liao Xinpei, and naturally, including Fan Jing.

But they didn't have any intersection at all.

Fan Jing has good academic performance, but is not good at sports. Liao Xinpei has poor academic performance, but has strong motor nerves.

Fan Jing's heartbeat was now inexplicably beating when asked by the other party.

What's wrong today?

Liao Xinpei sat down next to her, and did not bother her or not, and pushed a small notebook in front of her.

Fan Jing glanced at it and found that there was a handwritten chemistry topic.

【When calcined chromite, chemical reaction occurs:

Fe(CrO2)2+Na2CO3+O2——Fe2O3+Na2CrO4+CO2

Please balance the chemical equation.]

Um……

A very simple question.

Junior high school students can easily answer the questions, why is Liao Xinpei already in the first year of high school and can't even have such a simple question?

But why did Liao Xinpei think of coming to find me?

"How is it? Teach me." Liao Xinpei said.

Fan Jing nodded, picked up the pen and started answering.

"Chemical equation matching is a must-have question in the college entrance examination. Whether this question is difficult or not is the key to finding a method of matching.

The difficulty is that for most students, balance is time-consuming, especially for some elements with multiple prices, such as iron, which have both positive and positive 3 valences, they must be balanced with charge conservation."

Two minutes later, Fan Jing finished writing the answer to the question.

"Huh?" Liao Xinpei was stunned by the side, "Is it done?"

"Yes." Fan Jing blushed and nodded in a low voice.

"Wow, awesome, I'm worthy of being the first place in my age," Liao Xinpei seemed extremely excited, "Then teach me how to do this?

I want to be as good as you.”

Yes ~

【I want to be as good as you.】

This sentence was like a spell, knocking open Fan Jing's heart.

What does this mean?

Why did Liao Xinpei suddenly come to me for questions today, and he is so good at speaking?

Could it be...?

She raised her big eyes slightly and glanced at the boy next to her, feeling confused.

Could it be that Liao Xinpei...

Fan Jing quickly lowered her head, and she didn't dare to think about it anymore.

The entire problem-solving process is written on the notebook:

[Suppose that the coefficients before each molecule are A, B, C, D, E, F respectively.

Then, get the equation:

AFe(CrO2)2+BNa2CO3+CO2——DFe2O3+ENa2CrO4+FCO2

The system of equations is obtained according to the law of conservation of mass:

A=2D

2A=E

4A+3B+2C=3D+4E+2F

2B=2E

B=F

Then let E=1

Obtain multiple system of first-order equations:

A=2D

2A=1

4A+3B+2C=3D+4+2F

2B=2

B=F

Solution:

A=1/2

B=1

C=7/8

D=1/4

E=1

F=1

Then multiply by the smallest common multiple of 8

Get A=4

B=8

C=7

D=2

E=8

F=8

The balance result is:

4Fe(CrO2)2+8Na2CO3+7O2——2Fe2O3+8Na2CrO4+8CO2]

Fan Jing patiently explained to Liao Xinpei:

"The universal balance method I use here is not the fastest balance method and even seems a bit clumsy, but it is easy to master because when you understand the principle, you only need to solve the system of equations.

You see, here, each element has a coefficient, and then you will find that the sum of coefficients of the same element, the left and right sides should be equal..."

After Fan Jing's explanation, Liao Xinpei's eyes gradually lit up.

"The so-called universal balance method is actually to use the law of conservation of mass and charge to convert the balance of chemical equations into multiple systems of first-order equations in mathematics to solve the problem.

And this solution is the only solution.”

This is a very simple and fast method, and you don’t need to think carefully. Just list the equations according to what Fan Jing said to do, in the end it will be just a test calculation speed.

Elementary school students can also answer quickly.

"Wow!" Liao Xinpei looked extremely excited, "Fan Jing, you are really a genius! My God, I actually understand!"

It's really shameful to say that this is probably the first time in Liao Xinpei's life that he heard such a simple and easy-to-understand matching method. Before, he always thought that it was really difficult to do chemistry questions, and it was even more difficult than to score a three-pointer that was too far away.

"Thank you! Thank you Fan Jing!"

"No...no thank you... classmate, classmate... it should be." Fan Jing said in a low voice.

Her cheeks flushed throughout the whole process, like a big ripe apple.

"Well, then if I have any questions in the future, can I come and ask you again?" Liao Xinpei asked happily.

Why?!

Fan Jing was stunned for a moment.

this……

What does this mean?

Why did Liao Xinpei suddenly ask this?

Could it be...?
To be continued...