How to prove that the inhaled air contains less carbon dioxide than the exhaled air

The ratio of each component in the inhaled gas is the ratio of each component of the air.

Drain a bottle of exhaled air (bottle A) and take another empty bottle (bottle B) (i.e., a bottle of air).

You can put a lit match into bottle A and observe its burning - the flame will be small or even extinguished; Then put it in bottle B and observe its combustion - there is no change, indicating that the amount of carbon dioxide in the exhaled breath of the person is high - carbon dioxide does not support combustion.

You can also drop clear lime water into the two bottles separately, and after shaking, it is found that the lime water in bottle A becomes turbid. - Carbon dioxide can make clarified lime water turbid.

A device can be designed to first suck the air through a saturated sodium hydroxide solution (which reacts carbon dioxide) and then inhale it, and then pass the exhaled gas through another sodium hydroxide solution, with sodium carbonate (sodium bicarbonate?). ) generates proof that the exhaled breath contains carbon dioxide, i.e., proves that the human breath produces carbon dioxide, and the exhaled air contains more carbon dioxide than the inhaled air. (This experiment is dangerous, do not use direct human breathing).

First, the air is inhaled through a saturated sodium hydroxide solution (the carbon dioxide is reacted), and then the exhaled gas is passed through another sodium hydroxide solution, with sodium carbonate, to generate carbon dioxide in the exhaled gas, which proves that the human body will produce carbon dioxide when breathing, and the carbon dioxide content of the exhaled gas is higher than that of the inhaled.

In this way, take the same amount of clarified lime water and put it in the air separately, and pour gas into one of the clarified lime waters. It will be found that the clear lime water of Ha Qi becomes turbid faster than it is placed in the air, proving that the carbon dioxide content of the inhaled air is lower than that of the exhaled gas!

Equation: Ca(OH)2 + CO2 == CaCO3 precipitation + H2O

To prepare a saturated hydrated lime solution, blow through a tube with an ear wash bulb (the composition is the same as normal inhalation), and compare it with blowing directly into it, and it will be found that the latter makes the solution cloudy. And then prove.

A bottle of exhaled air is collected using the drain gas collection method.

Collecting a bottle of air.

Measure it with a small wooden strip with Mars.

Take the same test tube of AB, pour the same clarified lime water, A is exposed to the air, and blow to the other B with a straw, the lime water in A is slightly turbid, and the lime water in B becomes obviously turbid.

Yes, of course. The exhaled oxygen content of a normal person is about 17%, and the oxygen content is about 17%, and the oxygen is still much higher than that of carbon dioxide. [When taking a deep breath, the proportion of carbon dioxide rises to 5%, which is sky-high. 】

Can you imagine that your nasal cavity, trachea, bronchial tubes, and breathing can completely squeeze air into your lungs without any retention?! Of course not! So there's a lot of inhaled air that doesn't actually participate in the gas exchange at all, and ends up going back and forth and coming out again.

The proportion of birds with double breathing can rise a little higher, but it does not exceed oxygen

1 Fill one gas collection bottle with water, cover a small part of the bottle mouth with a glass piece, then push the glass piece to cover the entire mouth of the bottle, and put the bottle filled with water upside down in the sink with the glass sheet.

2 Carefully insert the drink tube into the cylinder and blow slowly into the cylinder (be careful not to suck the water in the cylinder during ventilation) until the bottle is filled with exhaled gas. Immediately under the water, the bottle of the gas collection cylinder was covered with a glass piece, and then the head was taken out and placed on the experimental table.

3. Take 1 empty gas collection cylinder, the bottle is air, drop a few drops of clarified lime water into each bottle of air and a bottle of exhaled gas to observe the oscillation, there will be white precipitate in the gas collection bottle filled with exhaled gas, and it is almost invisible in the gas collection cylinder filled with air.

It indicates that the exhaled air contains more CO2 and the air contains very little. (CO2 reacts with clarified lime water to produce a white precipitate).

When people breathe, the oxygen in the air is converted into carbon dioxide, and at the same time the water vapor is brought out from the body, the exhaled air of the human body and the content of oxygen, carbon dioxide, and water vapor in the air are different, and the exhaled gas has the characteristics of "two more and one less" compared with the inhaled air, that is, compared with the inhaled air, the carbon dioxide and water vapor content increases, the oxygen content decreases, and the content of residual carbon oxide in the exhaled air before the second pin is more than that of the inhaled air

So the answer is repentance: correct

In terms of the proportion of breath exhaled by people, there is still more oxygen than carbon dioxide.

The normal air content is about 79% nitrogen

Oxygen is about 21%, carbon dioxide is about.

After human respiration, gas exchange occurs at the alveoli (using the diffusion of dust and migratory gases), and the carbon dioxide content increases a little, while the oxygen content decreases a little!

About 79% of the exhaled breath is nitrogen

Oxygen is about 16%.

Carbon dioxide is about 4%.

It can now be seen that the oxygen emission in the exhaled air is 5 percentage points lower than that of the inhaled air, but it is still 12 percentage points higher than the carbon dioxide (which has increased by almost 4 percentage points).

Prepare two Erlenmeyer flasks, as well as glass catheters, clarified lime water and other utensils, set them as shown in the figure, hold the breathing port with the mouth, inhale and close A, and close the hall when exhaling B, after repeating several times, it is found that the clarified lime water in the I bottle becomes turbid, and there is no change in the II bottle It proves that the air volcanic mountain exhaled by the human body is more than the carbon dioxide content of the inhaled gas

Therefore, the answer is: hold the breathing port with your mouth, close A when you inhale, close B when you exhale, and after repeating it several times, it is found that the clarified lime water in the I bottle becomes turbid, and there is no change in the II bottle, which proves that the exhaled gas of the human body contains more carbon dioxide than the inhaled gas