Differences between sodium acetate and sodium acetate trihydrate
Sodium acetate and sodium acetate trihydrate, although both are acetates, their properties and uses are different.

First, chemical composition
Sodium acetate, its chemical formula is $CH_3COONa $, composed of acetate ions and sodium ions. And sodium acetate trihydrate, chemical formula is $CH_3COONa · 3H_2O $, based on the structure of sodium acetate, contains three crystalline water molecules. This crystal water gives sodium acetate trihydrate different physical and chemical properties.

Second, physical properties
In appearance, sodium acetate is often white crystalline powder, while sodium acetate trihydrate is mostly colorless, transparent or white granular crystals. In terms of solubility, both are easily soluble in water, but sodium acetate trihydrate has a solubility at a specific temperature or is slightly different from sodium acetate because it contains crystal water. The melting point is also different. Sodium acetate has a higher melting point. Due to the presence of crystal water, sodium acetate trihydrate loses the crystal water first when heated, and the melting point is relatively low.

Third, chemical properties
Chemical properties, both have acetate commonalities. However, sodium acetate trihydrate is due to crystal water. In some chemical reactions, water can participate in the reaction or affect the reaction process and rate. For example, in the process of reacting with strong acid to form acetic acid, sodium acetate trihydrate is due to the presence of crystal water, and the humidity and ion concentration of the reaction system may vary from that of sodium acetate, which in turn affects the reaction rate and equilibrium.

4. Differences in uses
In the industrial field, sodium acetate is often used as a buffer and mordant in printing and dyeing, pharmaceuticals, photography and other industries. Due to its high purity and no crystalline water, it performs well in moisture sensitive reactions. Sodium acetate trihydrate is mostly used to make hand warmers, hot compress bags, etc., using its crystalline exothermic properties, and because it contains crystalline water, it may be more suitable in some industrial applications that require a moderate moisture environment.

In agriculture, sodium acetate can adjust soil pH, provide carbon sources for plants, and promote plant growth. Sodium acetate trihydrate is directly used for soil improvement due to its high water content. It may be necessary to consider the impact on soil moisture.

In summary, sodium acetate and sodium acetate trihydrate are different in chemical composition, physical properties, chemical properties and uses. In practical application, it is necessary to choose reasonably according to specific needs and scenarios to achieve the best effect.