"All compounds of selenium and tellurium are toxic." Liu Hualong made a serious reminder before doing chemical experiments.

This is both a reminder, a knowledge point, and a part of the experiment. Liu Hualong and his classmates wore goggles, masks, and gloves, and the experiment began.

Like sulfur, the brother of the oxygen group element, selenium and tellurium can form seo2 and teo2 when burned in the air.

Sizzle!

The red selenium powder burned indulge indulge in vain, and more than twenty balls of charming blue flames danced on the laboratory bench.

Ranjie stared at the selenium-light blue flames of him and Huang Yuhang, and he said in a daze: "What a demon, so beautiful, I want to keep burning like this."

Chemistry is an experimental science, and many chemical experiments are beautiful and concrete.

Chemistry textbooks say that burning selenium produces a blue flame, but only by burning selenium with your own hands can you understand and remember which blue color it is after burning.

Although chemistry is a tool, chemical experiments are much more vivid than physical experiments.

The big brother of physics is above and is powerful without being angry. His experiments always make Ranger feel the inviolable power.

Chemical tools have a low status, and their experiments come from the core of the slut, so Ranger really wants to infringe on it.

The combustion product selenium dioxide is a colorless crystal, which is very poisonous. Langjie reminds Huang Yuhang: "Watch it with your eyes, wear gloves to touch it, and wash your hands after the experiment."

"Yes!" Huang Yuhang strictly abides by the experimental regulations. He asked curiously: "Can you bring some selenium compounds out?"

"Brother, your idea is very dangerous." Ranger certainly did not allow his experimental partner to take chemical poison out of the laboratory, he could not bear the responsibility.

Huang Yuhang laughed and said, "I just asked casually, it's okay, hehehe."

The next step is to dissolve selenium dioxide in water and add chlorine. This operation is supervised by Huang Yuhang and Lanjie.

Huang Yuhang completed the experimental operation, and Ranjie objectively commented: "Yuhang, you do a good job, and your hands-on ability is not bad."

Huang Yuhang was greatly encouraged: "Of the many disciplines, my favorite is chemistry, and my favorite is chemistry experiments."

Liu Hualong walked back and forth, closely monitoring the students' every move. He said: "The substance in your beaker is a mixture of dilute selenic acid and dilute hydrochloric acid, which is oxidized by selenic acid by chlorine. Selenic acid mainly shows oxidation properties, and when encountering stronger oxidants, it shows reducing properties. Through this experiment, we observed that chlorine has stronger oxidation properties, and chlorine can oxidize selenic acid and obtain selenic acid."

"Setic acid and sulfuric acid have many similar properties. Selenium acid is a non-volatile strong acid, which has strong water absorption and can carbonize organic matter. Its oxidation is stronger than sulfuric acid. Hot concentrated selenium acid can dissolve metals such as gold, silver, copper, etc., and form the corresponding selenate salts. The mixture of hot selenium acid and concentrated hydrochloric acid is similar to aqua regia and can dissolve platinum."

"Platinum is a precious metal, and a mixture of aqua regia is more dangerous, so we can only understand the theoretical knowledge points, so we will not prepare a mixture of hot selenic acid and concentrated hydrochloric acid."

When Liu Hualong explained this knowledge point, Huang Yuhang was fascinated by the fact that he murmured to himself: "Senicone is a semiconductor material. There is selenium in the photoelectric tube. If the photoelectric tube is removed and burned, you can get selenium dioxide. It is not difficult to prepare chlorine, but electrolyzing salt water is done. With chlorine, you can get various concentrations of hydrochloric acid. So my raw materials are simple and easy to obtain, photoelectric tubes, salt, distilled water, and regular stores, and will not attract the attention of the clerks."

Ranjie looked at Huang Yuhang with admiration: "Brother, it seems that you really like chemistry. Your chemistry theory level is not low, and you also have certain experimental hands-on ability and divergent thinking. So what are you using liquids similar to aqua regia?"

Huang Yuhang said with certainty: "Of course it is used for scientific purposes!"

"That's good, that's good." Langjie was very pleased.

The experiment continued, and under the careful guidance of Teacher Liu, the students prepared sodium selenite.

There is another knowledge point here. Liu Hualong said: "Sodium selenite is highly toxic. Adults will die if they take one gram orally. However, under the supervision of professional doctors, oral administration of appropriate amounts of sodium selenite can prevent and treat Keshan disease, and the clinical effect is good and safe. Keshan disease has basically disappeared now. Sodium selenite has played a role in medicine. It is currently mainly used for industrial purposes."

"Well, remember!" Huang Yuhang stared at the white powdered sodium selenite, with a frenzy glowing in his eyes. He liked the knowledge points that were more practical, and could quickly understand and remember the relevant knowledge points.

Unlike sulfuric acid and selenic acid, telluric acid is a weak acid.

Due to time constraints, Teacher Liu did not instruct the students to prepare telluric acid. The relevant theoretical knowledge should be discussed. Liu Hualong said: "High school chemistry is mainly inorganic. Although there are only four oxygen elements, it is very important. I have talked about too much oxygen and sulfur. Selenium and tellurium should also attract the attention of students. Because the telluric acid is weakly acidic and can form hexa substitutes, the chemical formula of telluric acid is not h2teo4, but h6teo6 or te(oh)6. If the acid is weak to a certain extent, it can be oh. X-ray research has proved that the six oh-aligned within the telluric acid molecule form an octahedral structure around the telluric acid atoms..."

Huang Yuhang likes chemistry, and he likes varied chemical phenomena, colorful, mysterious and magical elements, and the specific properties of the compounds.

What he annoyed the most is that it is extremely theoretical and is separated from the microstructure of actual life. This track, hexahedral, octahedral, these things are invisible and intangible, and they are very boring and cannot be applied to actual life at all.

But now, Huang Yuhang listens to Teacher Liu’s discussion on microstructure very carefully.

The essential reason for the emergence of macroscopic phenomena is micro-operation at the microscopic level. Huang Yuhang has sublimated. After this chemistry experiment class, he humbly asked Ranjie for microscopic knowledge of oxygen elements.

All those who should transfer classes have been transferred away and are about to go to the third year of high school. There are no students who copy homework in Class 2 and 3 anymore, only students who learn from each other.

Ranjie saw Huang Yuhang's strengths, and the student had a persistent preference for chemistry.

Even if certain disciplines are tools, those who devote themselves to studying a discipline are worthy of respect.
Chapter completed!