Potassium carbonate CAS：584-08-7
Potassium carbonate (K₂CO₃), also known as potash or pearl ash, appears as a white, hygroscopic powder or colorless crystalline solid with a characteristic salty taste. It dissolves easily in water to form a strongly alkaline solution, while remaining insoluble in organic solvents such as ethanol.
Parameters
| Category | Specification & Details |
| CAS Number | 584-08-7 |
| Physical Properties | - Appearance: Yellow, odorless powder- Melting Point: 891°C (lit.)- Boiling Point: Decomposes- Density: 2.43 g/mL (25°C)- Bulk Density: 750 kg/m³- Specific Gravity: 2.29 |
| Solubility & pH | - Water Solubility: 1120 g/L (20°C); forms clear, colorless solution (1 M at 20°C)- pKa: 10.33 (20°C)- pH (aqueous solution): 10.52 (1 mM), 11 (10 mM), 11.36 (100 mM) |
| Storage & Stability | - Storage Temperature: +5°C to +30°C- Hygroscopic (moisture-sensitive)- Stability: Stable under normal conditions; incompatible with moisture, acids, magnesium bromine trifluoride/trichloride |
| Other Key Data | - UV Absorption (λmax): 260 nm (Amax 0.03); 280 nm (Amax 0.02)- Dielectric Constant: 5.6 (16.0°C)- Merck Index: 14,7619 |
Safety Information
| Category | Key Details |
| Hazard Classification | - Hazard Code: Harmful (Xn)- WGK (Germany): Water hazard class 1 |
| Risk & Safety Statements | - Risk Codes: 22-36/37/38-20/21/22- Safety Codes: 26-36-37/39 |
| Transport Information | UN 3262, Packing Group III |
| Regulatory & Reference | - RTECS: TS7750000- TSCA Listed: Yes- HS Code: 28364000 |
| Toxicity Data | Oral LD50 (Rat): 1.87 g/kg |
Potassium carbonate is widely used as a key additive in optical glass manufacturing, helping improve transparency, mechanical strength, and refractive properties. It also acts as a flux in welding electrodes, ensuring stable arc performance during welding. In textile dyeing, it serves as a reducing agent in vat dyeing and an anti-whitening agent in ice dyeing processes. Additionally, it effectively absorbs carbon dioxide and hydrogen sulfide, and when combined with sodium carbonate, forms an active component in dry-powder fire extinguishers.
