Ferrous sulfate is blue-green monoclinic crystal or particle, tasteless. Weathered in dry air, the surface in wet air is oxidized to brown alkaline ferric sulfate. It is tetrahydrate at 56.6 ℃ and monohydrate at 65 ℃. It dissolves in water and is difficult to dissolve in ethanol. Its aqueous solution oxidizes slowly in air and quickly at high temperature. Alkali or dew will accelerate oxidation. The relative humidity (D15) was 1.897

Anhydrous ferrous sulfate is white powder, containing crystal water is light green crystal, commonly known as "green alum", dissolved in water solution is light green. Ferrous sulfate can be used as chromatographic reagent to determine platinum, selenium, nitrite and nitrate by drop method. Ferrous sulfate can also be used as reducing agent, ferrite, water purification, polymerization catalyst, photographic plate making, etc.

Ferrous sulfate has a strong oxidation effect, so how to keep it from being oxidized at ordinary times? According to the unique properties of ferrous sulfate, the following points should be paid attention to when preserving ferrous sulfate at ordinary times:

1. Keep in a cool and ventilated place;

2. Keep away from fire and heat source, avoid direct sunlight as far as possible, and keep away from light;

3. Sealed packaging, can not contact with the air, to prevent moisture;

4. It should be stored separately from oxidant and alkali, and should not be mixed.

Considering the above requirements, the storage conditions of ferrous sulfate are as follows: low temperature, ventilation, drying, and separate from food raw materials.