Design an experiment to verify that respiration does produce carbon dioxide gas

If it is a chemistry problem, then please take a deep breath and blow into the clarified lime water with a straw, the lime water becomes turbid, and carbon dioxide is produced.

If it's a biology question, then.

Equipment: 2 Erlenmeyer flasks, 1 bottle of clarified lime water.

1.Plant respiration produces CO2, water.

Take two Erlenmeyer flasks A and B, and pour a small amount of clarified lime water into each Erlenmeyer flask.

On the day before the experiment, the representative put 100g of fresh and scalded vegetables (blanched in boiling water for 2-3min) into two airtight black plastic bags, inserted a hose to tie the bag mouth tightly, and clamped the hose with a water stopper. (marked).

Take two bags of vegetables, insert the hose into the Erlenmeyer flask with clarified lime water, remove the water stop clip, and gently squeeze the plastic bag.

It can be seen that the gas inside the plastic bag containing fresh vegetables is clarified, lime water becomes cloudy. And blanched vegetables cannot. This shows that respiration does not only produce CO2

Innovative design of "Experimental Innovation for the Production of Carbon Dioxide by Green Plant Respiration" (2).

First of all, the experimental device from left to right is a gas washing cylinder, a closed container, a gas washing cylinder, and the devices are connected by rubber tubes, the leftmost gas washing bottle is filled with sodium hydroxide solution, the closed container is filled with green plants, the clear calcium hydroxide solution is placed in the right bottle, and then air is introduced from the left bottle, if the solution in the right bottle becomes turbid after a period of time, it can be proved.

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

The experimental setup to verify the carbon dioxide content of the exhaled air from the lungs is why the devices are different for the two bottles.

It is necessary to carry out 3 experiments, first collect 2 bottles of air, 2 bottles of exhaled gas 1, verify the content of carbon dioxide, pour a small amount of clarified lime water into two gas collection cylinders respectively, and find that the turbidity of the gas collection cylinder containing the clear gas of Hubu is obvious. Indicates a high level of carbon dioxide in the pre-exhaled air pattern. 2. Verify the oxygen content.

The small wooden strips that burned were stretched into each other, and it was found that in the gas collection cylinder containing the exhaled gas, the flame was small, and the reputation was loud and the burning time was short. Indicates that the oxygen content in the exhaled breath is low. 3. Verify the content of water vapor, two pieces of dry glass, one in the air and one on the exhale, and find that when you exhale, there is a water mist on the glass sheet.

Indicates a high level of water vapor in the exhaled air.

(1) In order to create a comparison sample for the comparison experiment, the comparison gas should be sampled first, and the air and exhaled gas should be collected

So the answer is: use the drainage method to collect two bottles of exhaled gas and two bottles of air;

2) Oxygen content is tested according to the combustion-supporting properties of oxygen; According to the carbon dioxide can make the clarified lime water turbid, the carbon dioxide content is tested; The condensation of water vapor in the exhaled air was used to test the content of water vapor in the exhaled gas

So the answer is: Purpose.

Experimental manipulation. Experimental phenomenon.

Draw conclusions. Compare the presence of dioxide in air and exhaled air.

The amount of carbon gas.

Take a bottle of air and a bottle of exhaled gas, drop each into the clarified lime water, and shake.

The clarified lime water in the exhaled air becomes turbid, and the clarified lime water in the air does not change, and the carbon dioxide in the exhaled air is more than in the air.

Compare the amount of oxygen in the air compared to the exhaled air.

Put the burning sticks into the gas cylinders containing the exhaled gas and the inhaled air, and extinguish the sticks in the gas cylinders containing the exhaled gas; The wooden strips in the gas collector cylinder containing the air still burn the oxygen content of the air than in the exhaled air.

Compare the amount of water vapor in the air and exhaled breath, take two dry and cold glass pieces, and exhale into one of them.

The exhaled dry glass becomes blurred, and there is a mist of water on the glass, but no water mist appears on the glass sheet placed in the air.

The amount of water vapor in the air is less than in the exhaled air.

In order to test the change in the carbon dioxide content of the gas before and after breathing, we can blow into the cylinder and observe the experimental phenomenon.

Procedure: One bottle of exhaled gas was collected and one bottle of air was collected, and then the clarified lime water was introduced into two cylinders.

Experimental Phenomenon: The lime water in the exhaled gas collection cylinder becomes significantly turbid, while the lime water filled with air does not change significantly.

Conclusion: The amount of carbon dioxide in exhaled breath is higher than that in air.

Carbon dioxide

Generally, it can be prepared by calcining limestone at high temperature or by the reaction of limestone and dilute hydrochloric acid, mainly used in refrigerating perishable food (solid), as a refrigerant (liquid), making carbonized soft drinks (gaseous) and solvents for homogeneous reaction (supercritical state), etc., about its toxicity, studies have shown that low concentrations of carbon dioxide are not toxic, and high concentrations of carbon dioxide will poison animals.

First, take two noisy gas collection cylinders and fill them with CO2 and O2 respectivelyUse a wooden strip with sparks to place it at the mouth of the gas collection bottle, and the rekindling of the wooden strip is O2, and vice versaThis is the easiest.

Second, take two plastic bottles, add NaOH solution to them, and introduce CO2 and O2 respectively in the fast-ripening ones, and the plastic bottles become flattened with CO2, and vice versa

Three, take two test tubes, add clear lime water, respectively through the liquid Li CO2, O2, if there is turbidity that is CO2, fourth, take two test tubes and add water, pass into CO2, O2 into the purple litmus reagent, because CO2 is acidic, can make the purple litmus reagent red (it is not recommended to use this method, it should be that the acidity of carbonic acid is small, not obvious, and the stability of carbonic acid is poor).

Chemistry is actually not difficult.

A bottle of air sample and a bottle of exhaled air were injected with the same number of drops of clarified lime water and shaken. Observe the phenomenon. The observed cloudiness of the clarified lime water in the cylinder of the exhaled gas is observed to be cloudy, but there is no obvious phenomenon in the air sample, which proves that the exhaled gas contains a high amount of carbon dioxide.

Carbon dioxide can make the clarified lime water turbid, and the amount of carbon dioxide in the air is not enough to form an obvious experimental phenomenon, so the experiment can be designed as follows:

1) Operation: Collect a bottle of exhaled gas with the drainage method, and collect the air with a gas collection cylinder of the same size; Then the same amount of clarified lime water is added separately and shaken;

2) It is observed that the lime water in the exhaled gas is more turbid than the air Therefore, the answer is: (1) collect a bottle of exhaled gas by drainage, collect the air with a gas collection bottle of the same size, and then add the same amount of clarified lime water and shake it;

2) Observed lime water in exhaled air is more turbid than air