After the physics lab class, there is a chemistry class in the afternoon.

The feeling of the lab class is still good, but I don't know what the laboratory of the chemistry class looks like

In my simple cognition, I think chemistry and physics are very different.

Physics classes mainly talk about the external properties of some things and the principle of motion, and physics experiments will not make A become B. But in chemistry class experiments, A and B always produce a series of reactions together, or precipitate or produce some gas, and always A plus B becomes C and D.

It is precisely because of this that when doing physical experiments, unless you are really stupid enough to step on a mine and deliberately connect a short-circuit line, there are still very few physical experiments that can explode in other cases.

However, chemistry experiments are different.

Whether it is in a TV series, a book, an anime plot, or a real reality, there are countless cases of explosions occurring during chemical experiments.

When we learned that we were going to do a chemistry experiment in the afternoon, the whole class was boiling.

The reason for the agitation is not only because of excitement, but also because of fear, and I am not the only one who has worried about this kind of problem, what if there is an explosion?

When I went to do a physics experiment this morning, the other direction was the chemistry lab. I've been in class, and I didn't have a chance to sneak in in advance, but I only knew that there was only one large laboratory over there, and there were many pools next to it.

On the third floor, there was a row of faucet pools where you could wash your hands, and when I saw it, I thought it was strange, could it be convenient to put out fires in the event of a fire?

"What to do? I was a little scared. A girl in the back row took the hand of the girl next to her and said nervously, "It can't be caused by improper operation, right?" ”

The girl next to her also looked worried, thought for a moment, took out her chemistry textbook, and said, "Don't worry, I took a look, the experiments I learned this semester are relatively simple, and there shouldn't be any danger."

Besides, isn't there a teacher, we'll be fine, don't worry. I've heard my sister say that chemistry experiments in junior high school are not difficult, so don't worry about it. ”

The two men muttered for a moment, then silence returned.

Is there really nothing going on? When I left the dormitory door in the morning, I accidentally got caught in the door lock, and there was a bruise in the middle of my right index finger, and my right eyelid kept jumping from morning to noon.

As the old saying goes, "The left eye jumps wealth, and the right eye jumps disaster." ”

At first, I didn't believe it, thinking it was a lie. I can't be feudal and superstitious, but the chemistry class itself brought me a lot of mental pressure, and I didn't expect that there would be a chemistry experiment class...... When the pressure is high, the brain is a little less clear.

I also began to be honestly afraid, and opened the chemistry textbook in a panic, hoping that nothing bad would happen in the afternoon.

I opened my chemistry textbook and carefully read the chemistry experiment procedures that I would operate in the afternoon.

This chemical experiment was about the production of oxygen from potassium permanganate, and the book reads as follows:

1. Experimental principle: 2KMnO4 heating = = K2MnO4 + MnO2 + O2↑

Second, the specific steps of potassium permanganate to produce oxygen:

The first step is to assemble the experimental device (the catheter in the test tube can be slightly extended to facilitate gas export) and check the air tightness of the device.

In the second step, the drug is spread flat on the bottom of the test tube, a small ball of cotton is placed on the nozzle (to prevent the hot oxygen flow from blowing potassium permanganate powder into the tube), and the mouth of the test tube is tightly plugged with a single-hole rubber plug with the catheter.

In the third part, the test tube is fixed on the iron frame.

((1) Note that the mouth of the test tube should be slightly inclined downward to prevent the wet water in the drug from turning into water vapor after being heated, and the water flowing back to the bottom of the test tube when it is cold at the nozzle, so that the test tube will burst;

(2) The iron clamp of the iron frame should be clamped in the middle and upper part of the test tube, that is, about 1/3 away from the mouth of the tube)

In the fourth step, the alcohol lamp is lit and the test tube is heated. (When heating, the test tube should be heated evenly, and then the outer flame of the alcohol lamp should be heated in the part where the drug is located.) ）

In the fifth step, the collection begins when there are continuous and uniform air bubbles emitted from the catheter orifice.

((1) Before heating, the gas collection cylinder should be filled with water and poured into the sink to wait for collection;

(2) Do not collect bubbles at the beginning, otherwise the collected gas will be mixed with air;

(3) When there is a large number of bubbles overflowing from the mouth of the gas collection cylinder, it proves that it is full. ）

Sixth, when the collection is complete, remove the catheter from the water.

Step 7: Turn off the alcohol lamp and stop the heat.

The last step is to clean the instrument, restore the equipment, and leave the site in an orderly manner.

……

Is it so complicated?

Seeing so many tedious steps, I can't help but feel a little numb in my scalp. Is this an oxygen experiment? Can this collected gas be inhaled into the body?

I secretly prayed for myself in my heart that I would never draw a chemistry experiment during the high school entrance examination, or that the physics experiment was simpler and not easy to make mistakes.

As soon as the bell rang in the afternoon, everyone took their chemistry textbooks and set off for the chemistry lab.

"Majestic, high-spirited", crossed the corridor in front of them, and stairs, and went upstairs to the destination.

It's still a group of five or six people, a total of more than a dozen groups.

The chemistry teacher came up in slippers to open the door, and the door squeaked open, and the afternoon sun was very bright, and the moment the door was opened, a fine dust flew in the air.

I subconsciously covered my mouth and nose, and many of my classmates didn't realize this problem and coughed straight from ashes.

"Ahem, ahem, ahem......"

Walking into the laboratory, it is quite large, surrounded by transparent glass windows, which are very well lit and bright.

"Students, each of you groups first finds a seat for your own experiment. There are two sessions in this lab class, and it is important to ensure that every member of the group does it once and is proficient in the operation. The chemistry teacher stood in front of our relationship and patiently instructed, "Okay, let's get started." ”

What the? Is it just the right start? Isn't there a live demonstration like a physics teacher?

We were very obedient and went to our respective tables.

"This, how?" I picked up the lab equipment on the table, some transparent measuring cups, beakers, etc., and asked my teammates next to me.

They shook their heads again and again, and said, "We don't know! Why don't you set an example? ”

I wanted to refuse, but in front of everyone, it's hard to say that I won't, right?

I took the bag of potassium permanganate in his hand, and it turned out to be a finely granular brown-black material, why did it look so much like the mud used for medium flowers?

"Alright then, I'll try first...... If you can't do it well, you can read it and don't laugh at me. ”

Check the tightness of the equipment first to see if there is any air leakage. Now that I've checked my operations, I'm going to start the second step. Put the medicine flat, take it, I'll grab some medicine first.

Looking at the machine in front of me, I grabbed a handful of potassium permanganate and put it in the container......

"Oh my God, how can you grab it with your hands?" Zhang Ying looked at me in surprise and asked.

"It's okay, it's not dirty, I'll wash my hands later,......" I replied nonchalantly, patiently fiddling with the equipment in my hand.

"Uh...... Ling Yue, you can take a look at your hands first. He kindly reminded.

What happened to my hand?

Could it be that this potassium permanganate is corrosive?

I looked at my hand in horror, oh my God, why is the palm of my right hand black?

The first reaction was to immediately put down the operating equipment in his hand and go straight to the pool.

"Why can't you wipe it off?"

I was at the edge of the pool, unscrewing the faucet, enlarging the water and rushing it, but I couldn't wash it off.

Seeing that the palm of his right hand was pitch black, he almost cried.

Fortunately, later, the teacher also came out to see what was wrong with me, and he smiled and said, "You're fine, you'll be fine in a few days, don't worry." ”

"Teacher, how many days will it take?"

"This, I don't know the specifics, it depends on your metabolism speed......

Me: "......"

。 m.