Sodium stearate(822-16-2)

Basic Information

• Chemical Name: Sodium stearate
• IUPAC Name: Sodium octadecanoate
• Molecular Formula: C₁₈H₃₅NaO₂
• Molecular Weight: 306.46 g/mol

Structure

• Sodium stearate consists of a long hydrocarbon chain, which is derived from stearic acid and is hydrophobic (water-repelling), and a carboxylate group (-COO⁻) that is ionically bonded to a sodium ion (Na⁺). The carboxylate group is hydrophilic (water-attracting). This dual nature of the molecule, with a hydrophobic tail and a hydrophilic head, makes it an amphiphilic compound.

Properties

• Physical Properties: It is usually a white solid at room temperature. It has a faint, characteristic odor. Sodium stearate is soluble in hot water and ethanol, but insoluble in cold water and many organic solvents.
• Chemical Properties: It is a relatively stable compound under normal conditions. However, in the presence of strong acids, it can react to form stearic acid and the corresponding sodium salt of the acid. For example, when reacted with hydrochloric acid, it forms stearic acid and sodium chloride.

Production

• Sodium stearate is typically produced by the saponification reaction of stearic acid with sodium hydroxide. The reaction can be represented by the following chemical equation: C₁₈H₃₆O₂ + NaOH → C₁₈H₃₅NaO₂ + H₂O. In this reaction, stearic acid (C₁₈H₃₆O₂) reacts with sodium hydroxide (NaOH) to form sodium stearate (C₁₈H₃₅NaO₂) and water (H₂O).