Sodium acetate crystals (the chemical formula NaC2H3O2·3H2O) can be used in the following fields: 1. Chemical synthesis: Sodium acetate can be used as a reagent or catalyst in various chemical reactions. 2. Heat packs: Sodium acetate crystals can be used in heat packs, where they are heated and then cooled to create a reusable heat source. 3. Food industry: Sodium acetate is used as a preservative, flavoring agent, and pH regulator in the food industry. 4. Textile industry: Sodium acetate is used as a dyeing auxiliary and as a buffering agent in the textile industry. 5. Medical industry: Sodium acetate is used in the medical industry as a diuretic and in the treatment of metabolic acidosis. 6. Agriculture: Sodium acetate can be used as a herbicide and as a growth regulator in agriculture.