Formula: C₈H₁₈N₂O₄S (HEPES free acid, in solution as sodium salt) CAS: 7365-45-9 (free acid) EC No.: 230-907-9 M (Molar Mass): 238.30 g/mol (free acid) D (Density): ~1.05 g/cm³ mp (Melting Point): Not applicable (solution) bp (Boiling Point): ~100°C Optical Rotation: Not applicable

Concentration: 1.0 M (± 0.02 M) HEPES in water, pH adjusted to 7.0 - 7.5 with NaOH. Appearance: Clear, colorless solution. pH: 7.0 - 7.5 (at 25°C). Sterility: May be sterile filtered (0.2 μm). Endotoxin: < 0.1 EU/mL (if specified).