The nature, production, collection, test and completion of carbon dioxide

- Dec 30, 2017-

Carbon dioxide is a very common gas. Do we know the knowledge of  the physical and chemical properties, the production, the collection and so on? Today, we will introduce it in detail so that readers can understand more deeply about carbon dioxide.

1.Physical and chemical properties

Physical properties

It is colorless and tasteless. The density is larger than the air, and it can be dissolved in water.

Chemical properties

Flammability: not burning or supporting combustion.

The reaction of carbon dioxide and water can produce carbonic acid, and the reaction of carbon dioxide and sodium hydroxide to produce white calcium carbonate.

2.Production (Laboratory)

Medicines: Dilute hydrochloric acid, marble/ limestone.

Generating equations: CaCO3+2HCl═CaCl2+H2O+CO2

Matters needing attention

1.The marble/ limestone cannot be replaced by sodium carbonate, because if use sodium carbonate, the reaction speed will be too fast and the carbon dioxide is difficult to collect.

2.Sulphuric acid cannot replace dilute hydrochloric acid. If use sulphuric acid, the sodium carbonate which is slightly soluble in water will be produced and prevent the marble/ limestone from reacting.

3.Concentrated hydrochloric hydrochloric acid cannot replace dilute hydrochloric acid, if use concentrated hydrochloric acid, the generated carbon dioxide will not be pure, because concentrated hydrochloric acid is volatile and produces impurities.


The collection of carbon dioxide is mainly used in the upward air method, because the density of carbon dioxide is larger than that of the air.

4.Test and completion

Test: Put the gas into the clarified lime water, if the lime water turns turbid, then the gas is carbon dioxide.

Full test: Ignite the match and put it in the mouth of the gas collecting bottle. If the match is extinguished, it will prove that the carbon dioxide is full.