I have done hundreds of technical tests without any accidents. This time I finally encountered dangerous goods.

According to the experimental precautions in chemistry textbooks, if your hands accidentally come into contact with dangerous drugs, you should rinse them with clean water immediately. If they are toxic, it is best to clean them with soap.

Li Mengxi washed his hands with clean water. Even after washing, the area on the back of his hand where the solution dripped was still burning. He rubbed it with his fingers and a layer of skin came off directly.

Li Mengxi looked at the injured back of his hand. He was thankful that he was cautious and did not extend his fingers directly, otherwise the whole finger would be injured.

This is the first step of the test. The test is completed and it has been tested. The unknown substance is extremely corrosive and toxic. The degree of toxicity can be determined after a few days by looking at the wound healing.

Li Mengxi was very confused. He didn't understand what the highly corrosive substance he had produced was.

Potassium hydroxide, plus calcium hydroxide, produced something that was suspected of being a calcium carbonate precipitate, as well as a highly corrosive substance of unknown composition.

Li Mengxi took the obtained materials back to the city lord's palace.

When he arrived at the City Lord's Mansion, after thinking for a long time, he decided to start doing some small experiments to explore the properties of matter.

Assume that the white precipitate is calcium carbonate, then how to determine whether calcium carbonate is calcium carbonate? Based on Li Mengxi's limited knowledge, there are only two methods he can think of.

When calcium carbonate is added with acid, it will bubble, which means carbon dioxide gas will be produced.

Also, after calcium carbonate is calcined, it turns into quicklime, which is calcium oxide.

Based on these two points, the testing method is developed.

Li Mengxi divided the white precipitate into two parts, one part was taken for calcination, and the remaining small part was prepared for other experiments.

Adding acid to calcium carbonate will produce carbon dioxide, and carbon dioxide will precipitate when it meets lime water. Therefore, the experimental method is to pour some white vinegar on the white sediment, and then see if it bubbles or generates gas, and then check the gas generated.

Will the lime water become cloudy?

The experimental process is not difficult, but it requires special experimental equipment, a sealable reaction vessel, and a tube with good sealing performance.

Li Mengxi couldn't help but frown. He found that the required equipment was not available at all and was difficult to find.

When things came to a close, Li Mengxi realized that more and more new materials would appear in the future, which would inevitably lead to more and more complex experiments. Therefore, professional experimental equipment became necessary.

Li Mengxi was not very good at chemistry. He drew a few sketches based on the few impressions he had. Among the sketches was a medium-sized urn used for cooking and heating. The urn had a long body and a small mouth, and was almost cylindrical.

, which is similar to a large test tube.

In addition, there are some thin ceramic tubes, which are long, short, straight or curved. The function of the ceramic tubes is to replace the rubber tubes used for sealing.

[To be honest, I have been using Yeguoyuedu to read and catch up on books recently. I can switch sources and read aloud with many sounds. Yeguoyuedu is available for Android and Apple.]

The rest include small sinks, small Erlenmeyer flasks, small spherical flasks, and other items.

Regular experimental equipment uses glass test tubes. Now that there is no glass, we can only use clay instead. Although clay is a bit bulky and fragile, clay is completely sufficient as a basic experimental equipment.

The chemical properties of pottery seem to be very insensitive. The pottery pots can be filled with wine, vinegar and all sorts of things, and nothing has ever corroded the pottery pots.

Taking the sketch with him, Li Mengxi went to the kiln again.

The person in charge of the kiln was not there, so he took his people out to look for soil. He found a potter at random, and Li Mengxi gave the sketch to the potter and explained it, including the rough specifications of various utensils, and made sure that the potter understood.

, Li Mengxi left the kiln.

After Li Mengxi left, the unknown potter looked at the drawings and scratched his head. Although the utensils were strange in shape, they were nothing more than bottles and jars. They were all easy to make, except for the pottery pipes with long, thin fingers, short and twisty fingers.

Very easy to do.

The craftsman thought for a while and decided that the clay tube was too thin and the clay embryo was difficult to knead. He could wrap it in a wooden stick to make it.

The basic equipment of the experimental equipment has been solved, and what is left is the sealing component, that is, the piston that connects the tube and the vessel.

For this type of piston assembly, if there is rubber, you can use rubber. If there is no rubber, you can use wooden plugs. The best wooden plugs are cork. The best common cork is willow. Willow is easy to find and it is not difficult to make willow plugs.

——

The two substances obtained in the experiment were suspected to be calcium carbonate precipitates. One was taken for calcination, and the other was reserved for adding acid for testing. Due to lack of equipment, this project was temporarily put on hold.

There was another extremely corrosive substance left. Testing this kind of substance gave Li Mengxi a difficult time.

Different from the white precipitate, it is known that the white precipitate is suspected to be calcium carbonate, and at least there is a direction for testing. However, for this super corrosive substance, there is no clue at all.

The city lord's mansion was quiet, with only Li Mengxi alone. Li Mengxi leaned on his chin, thinking quietly, how to test the properties of substances?

Common substances include acids, alkalis, salts, oils, alcohols, etc. To test these common substances, the method seems to be to use the properties of one substance to test the properties of another substance, and add various drugs together...

If the substance is a base, then adding an acid will neutralize it. The phenomenon of the neutralization reaction is...forgot. The neutralization reaction produces water, and no gas is produced, so it is difficult to judge the occurrence of the reaction from the appearance. But, it seems that,

Most reactions will either release heat or absorb heat. When the reaction cannot be distinguished from the appearance, you can feel it with your hands.

If two solutions are mixed together, and after a while you find that the mixed solution has become colder or hotter, then it is most likely that the two solutions have reacted.

(Well, you can feel the temperature with your hands...) Li Mengxi thought to himself.

Or an alkali? I don’t know what the reaction will be if the alkali is added to alcohol.

I don’t remember what reaction will occur when alkali is added to salt.

This chapter is not over yet, please click on the next page to continue reading! I still don’t remember what reaction will occur when alkali is added to starch.

Add alkali to grease. If the substance is an alkali, then once some oil is poured in, a saponification reaction will occur and soap-like substances will be generated.

Li Mengxi already figured out how to test the types of substances.

You can combine unknown substances with acids, alkalis, salts, and various other substances, and gradually determine their properties based on the special chemical reactions between different substances.

After figuring it out, Li Mengxi immediately started experimenting.

He found several clean bowls and prepared several bowls of solution.

Then, in the first bowl, he added flour Huhu. After adding it, he stirred for a while. After stirring and stirring, Li Mengxi found that the flour turned blue.

"Eh?!" Li Mengxi stopped stirring, he was surprised, and looked at the flour that changed color in surprise.

The flour turns blue as if it has been poisoned. What is the reason?

Li Mengxi clearly knew that the main component of flour was starch, and the starch changed color due to the addition of unknown strong corrosive substances.

Li Mengxi hesitated and hesitated, resisting the urge to take the blue Mianhu in his hands and knead it. The previous test was still fresh in his memory. It was too corrosive and burned his hands.

Flour was the substance that Li Mengxi thought was the least likely to be useful, but unexpectedly, incredible changes occurred, which surprised Li Mengxi and made him a little excited.

Then, he added a high degree of alcohol to the solution and stirred it for a long time. During this process, there was no reaction.

After stopping, Li Mengxi casually put his hand on the bowl and felt it. Perhaps it was an illusion, but Li Mengxi felt that the bowl seemed to have become a little warmer.

Li Mengxi couldn't help but frown. He picked up the solution and looked at it. A high degree of alcohol was added to the unknown substance solution. After stirring for a long time, there was no reaction at all.

But why did the bowl get hot?

Puzzled, Li Mengxi touched the other bowls with his hand. By comparison, he found that it was not an illusion. The other bowls were very cold. After the alcohol was mixed with the solution of the unknown substance, the bowls did become obviously hotter.

Li Mengxi was full of doubts about this strange experimental phenomenon. He thought about it and thought of various possibilities. One possibility was that a reaction really took place and the reaction produced heat; the other possibility was that he vaguely remembered that when concentrated sulfuric acid was diluted with water,

, will also generate heat violently, but when concentrated sulfuric acid is diluted with water, no chemical reaction occurs.

Therefore, it is unknown whether it is the heat generated during dilution or a reaction.

In response to this strange phenomenon, Li Mengxi took note of it carefully.

It was really amazing. I tried two things in a row. I added flour and the flour turned blue. I added high alcohol and it released heat.

Then, the third test, white vinegar.

After adding the solution of white vinegar and unknown substance, stir for a long time, stir for a while, and then stop. The color of the solution does not change, no bubbles are generated, and no phenomenon occurs.

When Li Mengxi touched the edge of the bowl as usual, he felt slightly warm again.

Li Mengxi was stunned for a moment, (Nima, did you react again?)

This is just ridiculous, why are they happening one after another, as long as they are objects, they can react?

He couldn't figure it out, he really couldn't figure it out, so Li Mengxi had no choice but to write down the experimental phenomena.

Finally, there is one last thing left, and the last thing is butter.

Li Mengxi poured the solution into the butter. As soon as he poured it in, the butter became turbid, producing a milky white oily product.

The reaction happened so quickly that Li Mengxi was surprised.

Then, he immediately stirred the butter. Stirring and stirring, the small half bowl of butter solidified and turned into a semi-solid paste.

Stopping his movements, Li Mengxi brought the bowl to his eyes and observed it. Looking at the solidified product in the bowl, the more he looked at it, the more he felt that this thing looked like soap! Why did he stir it, and the soap came out...

By this time, Li Mengxi had some vague guesses about the composition of the unknown substance.

In order to determine whether the product produced from butter was soap, Li Mengxi dug a little from the bowl, ran outside, rubbed the suspected soap with water and washed it. Once he scrubbed, bubbles appeared.

It is a greasy solid in the form of an ointment. When washed with water, there will be a lot of foam, which can make your hands very clean. It looks like soap, feels like soap, is made like soap, and feels very much like soap when used. It is clearly soap.

!

The reaction of oil and fat to produce soap is a saponification reaction. The principle of the reaction is that oil and alkali are added. Butter is oil, so the unknown substance is...

"It's actually an alkali?" Li Mengxi's eyes widened.

Li Mengxi could not figure out why adding calcium hydroxide to potassium hydroxide could generate a highly corrosive alkali. This made no sense! Can alkali react with alkali?

In fact, Li Mengxi made one mistake from the very beginning. This guy was not good at chemistry. He thought that since lime water and plant ash solution are both alkaline, and it is known that the component of lime water is calcium hydroxide, then it should be taken for granted.

, plant ash is potassium hydroxide, this reasoning is so smooth and reasonable!
To be continued...