Concentrated sulfuric acid (strong oxidizing acid), P2O5 (acidic white powder), silica gel (it is a translucent porous solid with large internal surface area, which has good adsorption and strong adsorption on water. Silica gel containing cobalt salt is called chromotropic silica gel, which is blue when it does not absorb water and pink when it is saturated with water. )

2. Alkaline desiccant: alkali lime, CaO and solid NaOH.

Alkaline lime (it is a white solid, mainly composed of CaO and NaOH), CaO (it is a white solid, alkaline oxide) and solid NaOH (strong alkali)

3. Neutral desiccant: anhydrous CaCl2 and CuSO4.

Anhydrous CaCl2 _ 2 (white porous solid) and CuSO _ 4 (white powder, which has a small degree of water absorption and is generally used to test the existence of water, and turns blue CuSO _ 4 5H20 after water absorption).

Extended data

Function of desiccant

1, keep the shoe cabinet from stinking

Shoes stink, mainly because of sweat and bacteria on the feet. If you put a few bags of desiccant into the shoe cabinet, it will absorb water, so that the shoes can be dried as soon as possible, and then opening the shoe cabinet will not be so embarrassing.

2. Prevent clothes and shoes from becoming moldy

When changing seasons, put a few bags in your shoes, bags or clothes pockets to prevent clothes from getting wet, moldy and deformed.

3. Keep the seeds dry

The collected seeds are afraid of germination due to moisture, so you can put desiccant in the storage box, so you are not afraid!

4. Prevent metal tools from rusting

Put a few bags of desiccant in the toolbox to slow down the rust of tools. Like a razor that often touches water, the effect of using desiccant is very obvious!