What is the principle of the downward exhaust air method, what is the principle of the exhaust air m

Because the molecular weight of oxygen is less than 29, it is smaller than air.

According to Avogadro's law, comparing the density can be used to calculate the formula quantity of gas, and the formula quantity of air can be seen as 29. The opposite of this is the upward exhaust method. Gases that do not react with air and have a large difference in density from air density can be collected by the air exhaust method, and the gas with a relative molecular mass greater than 29 is collected by the upward air exhaust method, and the gas with a relative molecular mass of less than 29 is collected by the downward air exhaust method.

Generally, the gas that can be collected by the drainage method should be used as much as possible, because the gas collected by the drainage method is of high purity, but contains a certain amount of water vapor. Hold the sparkled strip close to the mouth of the gas collector cylinder, if the strip rekindles, it means that the oxygen has been collected.

Up is denser than air.

Down is the density is not air small.

When the density is small, it will run upward.

The air will be expelled downwards.

You'll be able to collect the gas you've collected.

= **Same? I didn't see it. Can you make it clear?

The density is smaller than air, simply put, it is lighter than air, and the relative molecular mass is less than 29, so the heavier air sinks, sinks to the outside of the gas collection cylinder, then it is discharged downward.

Of course, that's what it says in theory. There will be impurities in actual operation. The smaller the relative molecular mass, the better. Approaching 29 is still better for drainage (provided that it is insoluble in water, of course).

According to the buoyancy calculation formula, the amount of buoyancy The density of the liquid or gas discharged, when the density of the gas to be collected is smaller than that of air, the buoyancy force it experiences (that is, the gravitational force of the air it expells) will be greater than its own gravity (because of the gravitational mass and gravity coefficient of the object), so it will float upward.

Upward exhaust air is denser than air. > is like capturing carbon dioxide. It extinguishes the candle that stands at the bottom of the cup. Explain that it does not support burning. Because the density is greater than air, it settles at the bottom of the cup.

The density is smaller than that of air, and the gas rises, and the downward air exhaust method is used.

The density is larger than the air, and the gas sinks, and the upward air exhaust method is used.

If the density is smaller than the air, the gas rises, and the downward air exhaust method is used

If the density is greater than the air, the gas sinks, and the upward air exhaust method is used

It should be noted that the difference between the density of the gas to be collected and the density of the air should be as large as possible, and if the density of the two gases is similar, it cannot be collected by the air exhaust method

I'm sorry, I can't make a flash picture.

Upward exhaust air method.

As the name suggests, it is to introduce gas and expel air upwards. When to use: The density of the prepared gas is greater than the density of the air.

when using, such as oxygen. Reason: The density of the gas is large, so it is heavier, and it sinks under the gas collection cylinder, so the air is driven out from above.

Downward air exhaust method: As the name suggests, it is to exhaust the air downward after the gas is introduced. When to use:

It is used when the density of a gas is less than that of air, such as ammonia. Reason: The gas produced is less dense, so it is relatively light, and floats above the gas collection cylinder, so the air is driven out from below.

The difference method: depending on the density of the gas you are making and the density of the air, which is larger and smaller.

Upward exhaust air method.

As the name suggests, it is to introduce gas and expel the air upwards.

When to use: The density of the prepared gas is greater than the density of the air.

. Take oxygen, for example.

Reason: The gas produced is dense, so it is heavier, and it sinks under the gas collection cylinder, so the air is driven out from above.

Downward air exhaust method: As the name suggests, it is to exhaust the air downward after the gas is introduced.

When to use: When the density of the prepared gas is less than the density of air. For example, ammonia.

Reason: The gas produced is less dense, so it is relatively light, and floats above the gas collection cylinder, so the air is driven out of Jingchun from below.

How to differentiate: When doing the problem, look at the density of the gas you are making and the density of the air. But how do we know how dense the gas is......Therefore, what gas is prepared by what method, Lao Lianghui will ask the master to memorize it.

I hope the landlord likes it.

Upward exhaust air method. Oxygen is denser than air, so the only way to exhaust air is to use it.

Since oxygen is denser than air, oxygen can be collected by placing the cylinder on the table and using a long catheter to introduce oxygen to the bottom of the cylinder. When collecting gases that are significantly denser than air, the upward air exhaust method is used; When collecting gases that are significantly less dense than air, the downward air exhaust method is used.

Introduction to the upward exhaust air method:

The upward air exhaust method is to introduce the gas and then expel the air upwards, which is usually used when the density of the gas is greater than the density of the air, such as oxygen.

Downward air exhaust method: As the name suggests, filial piety, is to introduce gas and discharge the air to Qiaohan land. It is usually used when the density of the prepared gas is less than that of the old air, such as ammonia.

Exhaust gas collection is the collection of gases that are easily soluble in water and do not react with components in the air, especially oxygen.