In the laboratory, carbon dioxide gas is generally prepared by what and what reactions

Carbon dioxide can be used to extinguish fires with calcium carbonate and hydrochloric acid CaCO3+2HCl=CaCl2+H2O+CO2 because carbon dioxide cannot be burned, and it does not support combustion in general, and the density is greater than the density of air. Dry ice (solid carbon dioxide) has a low temperature and, in general, it sublimates (changes directly from a solid state to a gaseous state) and absorbs a large amount of heat, so it can be used as a refrigerant. Dry ice is used for ordinary artificial rainfall and snowfall.

In addition, its low cost, wide range of raw materials, and relatively simple manufacturing are also the reasons why it is used as a refrigerant. Carbon dioxide can be used as gas fertilizer, which is also the use of carbon dioxide to provide plants for photosynthesis, and the greater the concentration of carbon dioxide, the faster the photosynthesis of plants, so carbon dioxide is usually used as gas fertilizer in greenhouses.

The laboratory uses marble and dilute hydrochloric acid to produce carbon dioxide CaCO3 + 2HCl = = CaCl2 + CO2 + H2O carbon dioxide fire extinguishing using carbon dioxide can not burn, does not support the chemical properties of combustion and the physical properties of density greater than air. Dry ice is used as a refrigerant because it takes away heat when sublimated, which can reduce the ambient temperature. Carbon dioxide is the main raw material for plant photosynthesis, so it is called gas fertilizer.

Carbon dioxide is produced in a laboratory.

Laboratory preparation of carbon dioxide.

1. Drug: dilute hydrochloric acid.

and marble (or limestone, the main component is caCO3).

2. Condition: room temperature.

3. Principle: CaCO3+2HCl==CaCl2+H2O+CO2

Note: 1) Dilute sulfuric acid cannot be used to prepare CO2.

Reaction with marble (or limestone), because the reaction CaCO3 + H2SO4 = = CaSO4 + H2O + CO2, the resulting CaSO4 is slightly soluble in water, precipitated in solution and wrapped in marble (or lime water.

outside, hindering the further occurrence of the reaction.

2) Concentrated hydrochloric acid is generally not used for the preparation of CO2.

Because of the volatilization of HCl gas, the collected CO2 is impure.

3) Substances that can react with dilute hydrochloric acid to form CO2 include Na2CO3 and K2CO3. na2co3+2hcl==na2co3+h2o+co2↑.from the reaction rate.

See, limestone (or marble) reacts moderately with dilute hydrochloric acid, and Na2CO3 reacts quickly with dilute hydrochloric acid.

4. Collection method:

Since CO2 is soluble in water and denser than air, the prepared gas adopts the upward air exhaust method.

Gather. 5. Device:

Depending on the fact that dilute hydrochloric acid is a liquid, limestone is a bulk solid, and the reaction is carried out at room temperature, the same three sets of equipment as the laboratory H2 can be used.

6. Full: Put the burning wooden strip at the mouth of the gas collection bottle, and the wooden strip is extinguished to indicate that it has been collected.

Junior High School Chemistry - Carbon dioxide produced in the laboratory.

The laboratory method is basically the reaction of carbonate and acid.

CaCO3+2HCl=CaCl2+H2O+CO2 (with dilute hydrochloric acid, reduce volatilization; Sulfuric acid cannot be used, as the resulting caso4 microdissolution prevents the reaction from continuing).

Na2CO3 + H2SO4 = Na2SO4 + H2O + CO2 (sulfuric acid is better than hydrochloric acid, no impurities caused by volatilization).

Experimental steps: 1) Install a simple device for producing carbon dioxide according to the drawing.

2) Add about 10 grams of block marble to the Erlenmeyer flask, and plug the rubber stopper with a long-neck funnel and a catheter.

3) The gas outlet tube is put into the gas collection cylinder, and the mouth of the conduit should be at the bottom of the gas collection cylinder.

4) Add an appropriate amount of dilute hydrochloric acid through the long-neck funnel, and gas is immediately generated in the Erlenmeyer flask.

5) After a while, strike a match, put the lit match on the top of the mouth of the gas bottle, if the match goes out quickly, it means that the gas bottle has been filled with carbon dioxide gas, cover the ground glass sheet, and put the mouth of the gas bottle up on the table for later use.

Key points: (1) For laboratory carbon dioxide, if marble is used as raw material, dilute sulfuric acid cannot be used. Because the calcium carbonate produced is a slightly soluble substance, it wraps around the surface of the marble, so that the acid cannot come into contact with the marble, thus aborting the reaction.

2) The laboratory can use the Qipu generator to produce carbon dioxide, so that it can be used at any time.

3) The drainage method can also be used to collect carbon dioxide gas, but the liquid in the tank is best to use saturated sodium bicarbonate solution, which will not cause carbon dioxide loss.

1.Pay attention to air tightness (step 2) to prevent outside gases from entering, resulting in impure carbon dioxide!

2.The mouth of the catheter should be at the bottom of the bottle, because the specific gravity of carbon dioxide in the air is different, so it should be at the bottom!

The reaction equation is CaCO3+HCl=CaCl2+CO2 The generator can be filled with a Qipu generator, or an Erlenmeyer flask.

Junior High School Chemistry - Carbon dioxide produced in the laboratory.

The simplest can be collected by the reaction of marble and dilute hydrochloric acid, and the balloon can be used with a round-bottom flask with a rubber stopper.

caco3+2hcl=cacl2+h2o+co2

Laboratories often use marble or limestone to react with dilute hydrochloric acid to produce carbon dioxide, and the main component of marble or limestone is calcium carbonate; Calcium carbonate reacts with dilute hydrochloric acid to form calcium chloride, water and carbon dioxide, and the chemical equation of the reaction is: CaCO3 +2HCl=CaCl2 +H2 O+CO2

So the answer is: dilute hydrochloric acid; Marbled; Limestone; Calcium carbonate; caco3 +2hcl=cacl2 +h2 o+co2 ↑．

Junior High School Chemistry - Carbon dioxide produced in the laboratory.

Marble (or limestone) reacts with dilute hydrochloric acid.

The reaction equation is:

CaCO3+2HCl===CaCl2+H2O+CO2 reaction principle is.

Strong acids prepare weak acids.

Acidic HCl is greater than carbonic acid.

Satisfied, thank you.

Junior High School Chemistry - Carbon dioxide produced in the laboratory.