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Anonymous users2024-02-06Cover with a lamp cap and repeat again.
If the catheter is in liquid, the catheter must be removed before the alcohol lamp is extinguished, otherwise sucking will occur.
Multiple alcohol lamps? We don't know which experiment it is, and we can't say for sure. The key is that you analyze the experimental process, especially in terms of safety, gas expansion and contraction, and water suction.
For example, when chlorine gas is used to make copper chloride, the alcohol lamp under the copper chloride reflection tube must be extinguished first.
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Anonymous users2024-02-05Connect the device from left to right and from bottom to top, as does the alcohol lamp. When dismantling, of course, follow the order of dismantling the device, which is exactly the opposite when it is installed, that is, the alcohol lamp used to make gas is finally extinguished, and the key is to prevent suction.
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Anonymous users2024-02-04Because the pressure of the area changes after the alcohol lamp goes out, pay attention to whether the part with the pressure change needs to be protected, and the reaction conditions of the substance in the area.
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Anonymous users2024-02-03Depending on what type of question it is, there is generally 1 heating to produce gas, 2 producing gas to participate in the reaction under heating conditions, and removing 3 flammable polluting gases. Organize and sort by yourself.
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Anonymous users2024-02-02This should be analyzed on a case-by-case basis, the most important thing is that the gas heating part is connected with the gas washing cylinder or the drainage gas collection part, and it is necessary to pay attention to the problem of suction.
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Anonymous users2024-02-01It must not be blown out, it must be extinguished with a lamp cap, and the cover must be repeated again, otherwise the pressure will be reduced during the lights out, which may cause the alcohol lamp to gasp.
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Anonymous users2024-01-31Do not blow, cover with a lamp cap and repeat.
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Anonymous users2024-01-30Continue ventilation and turn off the lights at the end.
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Anonymous users2024-01-29After the lid is extinguished, repeat the lid again.
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Anonymous users2024-01-28How many still have alcohol lamps, and electric stoves are better!
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Anonymous users2024-01-271.After the laboratory oxygen production experiment, the catheter should be removed first and then the alcohol lamp should be extinguished, the reason is: the spine fool who extinguishes the lamp first Due to the decrease in temperature, the volume of the gas decreases, resulting in a decrease in the internal pressure of the device, and the external pressure is stronger than that in the device, the water cherry silver will be sucked into the test tube, causing the hot test tube to burst, so the catheter should be removed from the water;
2.In the hydrogen reduction copper oxide experiment, the alcohol lamp should be extinguished first and then the catheter should be withdrawn, the reason is: after the copper oxide is reduced to copper, the temperature of the copper is very high, if the catheter is withdrawn first, let the fresh air containing high concentration of oxygen compared with the test tube enter, and the copper will be oxidized again to dry copper oxide.
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Anonymous users2024-01-26It depends on what experiments are done.
1.After the oxygen production experiment, the catheter should be removed first and the alcohol lamp should be extinguished, the reason is: if the lamp is extinguished first, the internal pressure of the device will decrease due to the decrease in temperature and the decrease in the volume of gas, and the external pressure will be stronger than that in the device, and the water will be sucked into the test tube, causing the hot test tube to burst, so the catheter should be removed from the water;
2.In the hydrogen reduction copper oxide experiment, the alcohol lamp should be extinguished first and then the catheter should be withdrawn, the reason is: after the copper oxide is reduced to copper, the temperature of the copper is very high, if the catheter is withdrawn first, the outside fresh air containing a high concentration of oxygen compared with the test tube enters, and the copper will be oxidized to copper oxide again.
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Anonymous users2024-01-25It depends on what experiments are done.
1.After the oxygen production test, the catheter should be removed and the alcohol lamp should be extinguished, because if the lamp is extinguished first, the temperature will decrease.
The volume of the gas decreases.
This results in a decrease in the internal pressure of the device.
The external pressure is stronger than that inside the device.
The water is sucked back into the tube.
Causing the hot test tube to burst.
So move the catheter out of the water;
2.In the hydrogen reduction copper oxide experiment, the alcohol lamp should be extinguished first and then the catheter should be withdrawn, the reason is: after the copper oxide is reduced to copper, the temperature of the copper is very high, if the catheter is withdrawn first, the outside fresh air containing a high concentration of oxygen compared with the test tube enters, and the copper will be oxidized to copper oxide again.
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Anonymous users2024-01-24Copper oxide is reduced to copper after 1After the laboratory oxygen test, the catheter should be removed and the alcohol lamp should be extinguished, because the lamp should be extinguished first.
Due to the decrease in temperature.
The volume of the gas decreases.
This results in a decrease in the internal pressure of the device.
The external pressure is stronger than that inside the device.
The water is sucked back into the tube.
Causing the hot test tube to burst.
So move the catheter out of the water; In the hydrogen reduction copper oxide experiment, the temperature of the copper is very high, if the catheter is withdrawn first, the reason is that the fresh air containing a high concentration of oxygen compared with the test tube is allowed to enter, and the copper will be oxidized to copper oxide again; 2
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Anonymous users2024-01-23The steps to light an alcohol lamp are:
1. Take away the lamp cap and set it aside. 2. Use a match to light an alcohol lamp from the bottom up.
The way to extinguish the alcohol lamp is to use the lamp cap to extinguish the alcohol lamp after use. Lift the lid after it is extinguished and cover it again.
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Anonymous users2024-01-221.After the laboratory oxygen production experiment, the catheter should be removed first and the alcohol lamp should be extinguished, the reason is: if the lamp is extinguished first, the internal pressure of the device will decrease due to the decrease in temperature and the decrease in the volume of gas, and the external pressure will be stronger than that in the device, and the water will be sucked back into the test tube, causing the hot test tube to burst, so the catheter should be moved out of the water;
2.In the hydrogen reduction copper oxide experiment, the alcohol lamp should be extinguished first and then the catheter should be withdrawn, the reason is: after the copper oxide is reduced to copper, the temperature of the copper liquid is very high, if the catheter is withdrawn first, and the fresh air containing high concentration of oxygen compared with the test tube is allowed to enter, the copper will be oxidized to copper oxide again.
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