November 8th!

It turns into light rain!

Lanjie came to the test site and took the theory test of the Huajing Recontest.

The full score of the theoretical test paper for the Recontest of Chemical Competition is 100 points. The first question is the element inference question, saying that metal a is often used for protection of iron, a reacts with chlorine to obtain b, b reacts with a certain reaction to c, c takes a certain reaction... The reaction has been reacted and new products are obtained, please write the chemical formula of a~i.

Key clue: Inject h2s into the hydrochloric acid solution of b to obtain a golden precipitate (commonly known as gold powder).

In recent years, as students continue to understand the knowledge of inorganic chemistry in universities, element inference questions have evolved from "skill examination" to "knowledge recitation", and even the words "memorize a certain book well and are fully proficient in element inference" have appeared, which is helpless and sad.

In this element inference question, players with good element chemistry can immediately infer that a is sn when they see the gold powder.

Is this true?

Yes, that's it.

Ranger knew that a must be sn. He took sn as the starting point and quickly deduced sncl4, sncl2, sn(c6h5)4...

The first question is a question that crushes the knowledge points. If you remember the relevant knowledge points, you can crush the first question. Otherwise, you will be crushed.

There is only one question in this paper similar to the first question. The remaining questions not only require sufficient knowledge from the contestants, but also require flexible skills.

The second question says that there is a type of organic/inorganic hybrid thin-film solar material in the field of photoelectric materials, which are frontier materials. This type of material consists of three ions. The crystal unit cell has 4 c3 axis along the diagonal of the body. A is a positive monovalent cation or group, and its fractional coordinates are (0,0,0). b is a metal pb2, sn2 cation, and its fractional coordinates are (1/2, 1/2, 1/2). x is a cl-, br-, i- and other halogen ions, and its fractional coordinates are (0, 1/2, 1/2), (1/2, 0, 1/2, 0).

Then the contestants were asked to use the knowledge and skills of crystal structure to find a series of results.

‘Is this thing a perovskite solar cell?’

Ranger sets this thing as a perovskite solar cell, and then starts his deduction and calculations.

No matter what this thing is, the first and second rules of pauling apply.

‘a and x together form a cubic packing!’

‘b is filled in the octahedral void composed of 6 x ions, so the coordination number of b to x is 6!’

‘Calculate to find the negative charge around x to be 1!’

‘That is, positive and negative charge balance, there are no discrete coordination ions, and the structure is stable!’

‘Yes, this thing is a perovskite solar cell!’

'Organic ions are cations of perovskite materials in organic/inorganic hybrid thin-film solar cells. The work function affects their contact with the direct contact material, thus affecting the energy conversion efficiency of the solar cell!'

‘The crystal skeleton composed of inorganic ions can stabilize the structure, effectively reduce carrier losses, and thus improve the performance of solar cells!’

‘See, the radius of a ion is 245~286pm!’

‘This perovskite solar cell has something to do! It’s worth studying!’

Ranger continued to study the subsequent topics and developed some experiences.

Ding Ding Ding!

carry out an assignment!

After the game, Qian Baoshan asked with concern: "Lanjie, how did you do the exam?

Ranger said confidently: "It's not a big problem to perform normally."

"That's good, then wait for the results of the theory test."

"Teacher Qian, I want to continue to improve my chemistry experiment hands-on ability these days as I waited for the theoretical score."

"No problem, I'll arrange for Teacher Qi to tutor your chemistry experiment one-on-one."

Under the arrangement of Teacher Qian, Teacher Qi, one of the experimental coaches of the Huajing team, immediately implemented one-on-one chemistry experiment tutoring for Lanjie.

On November 11, the scores of the Huajing Re-Second Recontest Theory Examination were announced.

Ranger, 98 points!

Another 2 points were deducted!

After entering the rematch of various subject competitions, why is it so difficult to get full marks?

To be honest, 98 points are also very high.

Ranger was qualified for the experiment in the rematch of the competition.

On November 13, the rematch experiment of the Huajing competition.

This experiment is a routine organic synthesis experiment, and Ranger completed this organic experiment with conventional operations.

The full score of the Huajing Experiment was 50 points. On November 15, the Huajing Experiment score was announced.

Ranjie scored 47 points in the Huajing Experiment, and the total score of the Huajing rematch was 145 points. He won the Huajing Provincial Prize! He was qualified for the Huajing National Final!

In this year's four major subject competitions in mathematics, physics, chemistry and biology, Lanjie advanced to the national finals.

Principal Wang Yongjia convened the leaders of various departments and units in Yangzhong to hold a meeting. He gave the latest instructions at the meeting: "The annual decisive battle has come! Please show the fullest spirit and the most professional technology to strengthen and strengthen the national finalists in the four major subjects of mathematics, physics, chemistry and biology in our school! I hope that the number of national first prizes in our school this year will exceed that of last year. I hope that no less than one student who has been selected for the official list of the national team will be included in the official list of the national team."

"We treat any student equally among us. On the basis of treating everyone equally, we can appropriately provide resources beyond the conventional scope to treat a very small number of extremely special students. There is no doubt that the student Lanjie who advanced to the four major subject competitions at the same time is such an extremely special student."

A teacher asked: "In the national finals of the four major subject competitions, Lanjie may create unprecedented great achievements. At this critical time on the eve of the national finals, it is necessary to give Lanjie unconventional resources. So, Principal Wang, what are the upper and lower limits of unconventional resources?"

Principal Wang said firmly: "Without violating the laws and school rules, any resources that are conducive to Ranjie's winning of the National First Prize can be given to him."

After the meeting, the leaders returned to their respective positions and conveyed the spirit of Principal Wang's instructions.

Ranger, who was actively preparing for the national finals of the four major subject competitions, shuttled through the competition classroom and laboratory.

"Teacher Qi, there is a type of chemical experiment that is particularly interesting. It is to use simple and easy-to-get raw materials to produce products with wonderful chemical properties through clever chemical operations. Can you teach me more about such chemical experiments?" Langjie made his request.

Teacher Qi asked: "Langjie, does this help you win the first prize in China?"

Ranger said with certainty: "Yes, it will help me win the first prize in China."

"Chemistry is an experimental science. It uses simple and easy-to-get raw materials to make chemical products with special and wonderful chemical properties. There are many chemical experiments of this type. Without further ado, let's start." Teacher Qi pulled out a list of simple and wonderful chemical experiments he knew.

Under the careful guidance of Teacher Qi, Lanjie performed these chemical experiments one by one, and he benefited a lot. His cognition of chemistry and his hands-on ability to chemical experiments have been continuously strengthened.
Chapter completed!