What gas can be dried with concentrated sulfuric acid

Concentrated sulfuric acid is a strong acid and can play an important role in many fields such as chemical industry. Its characteristics are water absorption, dehydration, and oxidation, etc. Concentrated sulfuric acid can dry gases, which are mainly divided into three types of gases: neutral gas, reducing gas and acidic gas. When using concentrated sulfuric acid, you must strictly follow the operating procedures. The hazards caused by improper operation are relatively large.

What gas can be dried with concentrated sulfuric acid?

Concentrated sulfuric acid can dry three types of gases: 1. Neutral gases, such as H2, O2, N2, CO, NO, CH4, etc.; 2. Acidic gases: SO3, SO2, CO2, HCl, HF, etc.; 3. Oxidizing gases: O3, F2, Cl2. Two types of gases cannot be dried: 1. Alkaline gases, such as ammonia (NH3); 2. Reducing gases, such as HBr, HI, H2S, etc. Because concentrated sulfuric acid is highly oxidizing and acidic, it cannot dry reducing gases and alkaline gases.

Characteristics of concentrated sulfuric acid

1. Water absorption: If you leave a bottle of concentrated sulfuric acid open in the air, its mass will increase, its density will decrease, its concentration will decrease, and its volume will increase. This is because concentrated sulfuric acid absorbs water. ⑴ As far as sulfuric acid is concerned, water absorption is a property of concentrated sulfuric acid, not of dilute sulfuric acid. ⑵The water absorption of concentrated sulfuric acid refers to the strong combination of concentrated sulfuric acid molecules with water molecules to form a series of stable hydrates and release a large amount of heat: H2SO4 + nH2O == H2SO4·nH2O, so the process of concentrated sulfuric acid absorbing water is a process of chemical change, and water absorption is the chemical property of concentrated sulfuric acid. ⑶ Concentrated sulfuric acid can not only absorb general free water (such as water in the air), but also absorb water in certain crystalline hydrates (such as CuSO4·5H2O, Na2CO3·10H2O).