What are the desiccants commonly used in laboratories？

1. H2SO4:

With strong water absorption, it is often used to remove moisture from gases that do not react with H2SO4.

2. Anhydrous calcium chloride:

low price, strong drying ability and fast speed. It is generally used to fill dryers and drying towers, to dry medicines and various gases. Cannot be used to dry ammonia, alcohol, amine, acyl, ketone, aldehyde, ester, etc.

3. Anhydrous magnesium sulfate:

It has strong drying ability, rapid water absorption, high efficiency, and low price. It is often used to dry organic reagents.

4. Solid sodium hydroxide and soda lime: fast water absorption, high efficiency, cheap, are excellent desiccants, but cannot be used to dry acidic substances. Commonly used to dry gases such as hydrogen, oxygen, ammonia and methane.

5. Color-changing silica gel:

commonly used to keep instruments and balances dry. Turns red after absorbing water. The expired silica gel can continue to be used after being dried and regenerated. Can dry amine, NH3, O2, N2, etc.

6. Activated alumina (AI2O3): large water absorption, fast drying, and regeneration.

7. Anhydrous sodium sulfate:

The drying temperature must be controlled within 30°C, and the drying property is worse than that of anhydrous magnesium sulfate.

8. Calcium sulfate: can dry H2, O2, CO2, CO, N2, CI2, HCI, H2S, NH3, CH4, etc.