A method to distinguish six gases: oxygen, air, carbon dioxide, hydrogen, carbon monoxide, and metha

Oxygen can rekindle the wooden strips with sparks, nitric oxide will turn brownish-red in the air, carbon dioxide will make the clarified lime water turbid, hydrogen will form water mist in the dry beaker from combustion, water mist will be generated in the dry beaker by combustion, methane will become turbid in the beaker with a layer of clarified lime water attached to the inner wall, and the rest is air.

Burning sticks of wood.

The combustion is the same as the air, the carbon dioxide is extinguished, and the oxygen is even more vigorous. Can ignite the gas is hydrogen, carbon monoxide, methane, cover a cold and dry beaker above the ignition gas, no water droplets produce carbon monoxide, there are water droplets produced upside down, add lime water, change the precipitate is methane, do not change is hydrogen.

Take samples from small test tubes, which can be ignited with CO, CH4, and H2; It is O2 that can rekindle the sparkled sticks; The igniteable gases are covered with dry cold beakers, and the water droplets at the bottom of the cups are H2 and CH4; The one without water droplets is CO; Then cover it with a beaker coated with lime water at the bottom of the cup (H2, CH4), the bottom of the cup is CH4 with white substance, and H2 without white substance;

Place the burning strip in the test tube where (air, CO2) is located, extinguish the CO2, and still burn the air.

If you see that the flame does not change significantly, it is carbon dioxide, and the flame is more oxygen, and the other three bottles are poured with clarified lime water (two of which have water droplets negative on the inner wall after ignition)**, if the bottle with water droplets becomes cloudy, it is methane, and the other bottle with water droplets is hydrogen, and the remaining bottle is only cloudy, which is carbon monoxide.

Methane is produced by combustion with both carbon dioxide (verified by clarified lime water) and water (verified by anhydrous copper sulfate).

Burning only water produces hydrogen.

Burning only carbon dioxide produces carbon monoxide.

The only thing that can directly make the clarified lime water turbid is carbon dioxide.

When the stick is ignited, it is oxygen that causes it to burn violently.

It is the air that burns normally.

What is extinguished (the gas cannot make the clarified lime water turbid) is nitrogen.

What ignites the gas is a wooden strip that burns with hydrogen, carbon monoxide, and methane.

The combustion is the same as the air, and a cold, dry beaker is placed over the ignited gas, and no water droplets produce carbon monoxide, extinguished carbon dioxide, and more vigorously oxygen.

There is oxygen, hydrogen, nitrogen, air,

How to identify the six gases of carbon monoxide and carbon dioxide?

Take 6 test tubes and pour in clarified lime water separately. Then, the trachea tubes on the rubber bags of the 6 gas storage tubes were inserted into the lime water of the 6 test tubes, and the free clamp was opened to observe the changes of lime water in the 6 test tubes. In one of the test tubes, the lime water became cloudy, and this gas must be carbon dioxide.

There was no change in the other five tubes. Close the free clip.

Take a sink and put the water away. Take 5 more gas collection cylinders, also fill them with water inside, and stand upside down in the sink. The remaining 5 kinds of gas are collected by draining the gas method, and the 5 bottles of gas are covered with glass sheets, taken out of the sink, and placed on the table.

Observe the phenomenon by placing a burning wooden stick on each of the five bottles that collect gas.

One of the bottles of gas that can make the wood stick more and more vigorous must be oxygen.

One of the bottles has no effect on the burning of the sticks, and if the gas in the bottle does not burn, it must be air.

One of the bottles must have been nitrogen.

When two bottles of gas meet the burning wooden bars, the gas in the bottles is ignited, and the flames are light blue when burning, at this time, a small amount of clear lime water is quickly poured into the two gas collection cylinders, covered with glass sheets, and the gas collection cylinders are shaken to observe the changes of lime water. If the lime water in one of the bottles becomes turbid, the original gas must be carbon monoxide, because carbon monoxide is burned to produce carbon dioxide, which makes the lime water turbid. If the lime water in the other cylinder does not change, the original gas must be hydrogen, because hydrogen combustion can only produce water.

1.The gas is passed into the clarified lime water, and it is carbon dioxide that becomes turbid;

2.The remaining gas (hydrogen, nitrogen, oxygen, carbon monoxide, air, methane) is introduced into bromine water, and (under light), the color of the mixture becomes lighter, and oil beads are formed inside the container, and methane is the one with white mist when the plug is opened.

3.The remaining gases (hydrogen, nitrogen, oxygen, carbon monoxide, air) are passed through the hot copper oxide, and the red substances are produced as hydrogen and carbon monoxide, which are purified and ignited, and the hydrogen with a blue flame is ignited.

4.The remaining gases (nitrogen, oxygen, air) are placed on a extinguished, spark-bearing match, and the rekindled is oxygen.

5.The remaining gas (nitrogen, air) is fanned by hand, and the person can breathe in the air.

Put the burning sticks into the gas collection cylinders, the sticks burn more vigorously with oxygen, the sticks extinguish carbon dioxide and nitrogen (and then use clarified lime water to separate the two), the burning phenomenon of the sticks remains unchanged is air, and the gas burns and emits a blue flame is hydrogen. Carbon monoxide. Methane, a dry beaker is covered above the three flames, the beaker does not appear in the water mist is carbon monoxide, and then the two beakers with water mist are turned upside down and poured into the clarified lime water to appear in the cloudy methane, and the other gas is hydrogen.

I think the physical method is faster to identify gases according to their different melting and boiling points and densities.

Chemical Methods:1When a saturated Ca(OH)2 solution is introduced, it becomes turbid to identify CO2 and air, and then see which one can support combustion.

CO CH4 was burned twice and identified by a dry glass and a glass sheet dipped in clarified lime water. The first is water vapor, the second is CO2, and the third is water vapor and CO2

3.The rest of the n2 that doesn't respond is n2

Just use matches and lime water.

When the gas meets a match, it produces a pale blue flame and is hydrogen.

When the gas meets the match, it makes the match burn more vigorously, and it is oxygen.

When the gas meets the match, it produces a dark blue flame, which is carbon monoxide, and when the gas meets the match, the match does not change significantly, and it is air.

The remaining gas is poured into the clarified lime water, making it cloudy with carbon dioxide, and the remaining unignited is nitrogen (or match extinguishing).

Step 1: Hold a wooden stick with a spark on it close to the mouth of the bottle containing the 4 gases mentioned above, and it is oxygen that can rekindle the stick.

Step 2: The remaining 3 unidentified ones are passed into the clarified lime water, and it is carbon dioxide that can make the lime water turbid.

Step 3: Put the remaining two into an upside-down dry beaker and ignite it, there are water droplets at the bottom of the cup to generate methane, and the last one does not need to be judged to be carbon oxide. (To be precise, copper oxide cannot be used to distinguish the last two, because the copper oxide from which methane passes into the calciant plum also produces carbon monoxide, but it makes sense in the book of destroying the shed).

Let's talk about it separately. This is the one that distinguishes hydrogen methane from carbon monoxide.

The three gases are ignited separately through a glass tube, and a dry beaker is inverted on each flame, and after a while, hydrogen and methane appear on the walls of the cup, and carbon monoxide is the non-perch beads; Then on the flame of hydrogen and methane, the beaker with clarified lime water is dipped on the wall of the cup, and the lime water becomes cloudy with methane, and the unchanged is hydrogen.

This is the distinction between oxygen, carbon dioxide, air, and nitrogen.

If the stick burns normally, the bottle will be filled with air, and if it is more vigorous, it will be oxygen. If it is extinguished, pour clarified lime water into the bottle, the lime water is turbid with carbon dioxide, and the unmixed is nitrogen.

a. The gas is introduced into the water respectively, and the four gases can not produce obvious phenomena, and the identification cannot be completed b. The burning wooden strip is extended into the bottle, and the gas without obvious change in the burning of the wooden strip is air; The gas that burns more vigorously is oxygen; The gas extinguished by the sticks is carbon dioxide gas; The gas can be burned with hydrogen The phenomenon is obvious, and the scheme is feasible

c. Purple litmus test solution is introduced separately, carbon dioxide can make purple litmus test solution red, only carbon dioxide can be identified, and the scheme is not feasible;

d. Only carbon dioxide can make the clarified lime water turbid, and it is difficult to identify the gas as air, hydrogen and oxygen, and the scheme is not feasible;

Therefore, choose B

Option d Carbon dioxide can make lime water turbid, and other gases are insoluble in water a, and no difference can be seen.

b It can extinguish the fire, but it is too dangerous, if you put in hydrogen gas to blow up c The carbonic acid solution is too weak to make purple litmus, and it will not change color like other three gases.

Answer B matches can identify oxygen, air and carbon dioxide, and use a clarifier to stare at gray water to check whether there is carbon dioxide in the combustion products of hydrogen and bright acres, so as to identify hydrogen and methane