Zinc chloride
| Frmula | ZnCl2 |
| Density | 2.91 g/cm3 (20°C) |
| Molar mass | 138.28 g/mol |
| CAS number | 7646-85-7 |
| HS Code | 28273600 |
| Storage | Without limitation |
| SDS | availeble |
| RTECS | ZH1400000 |
| R phrase | R 22-34-50/53 |
| S phrase | S 26-36/37/39-45-60-61 |
| Odour | odourless |
| Form | solid |
| Color | white |
| p H value | ~ 5 (100 g/20 °C) |
| Solubility in water | 4320 g/l( 25 °C) |
| Solubility in ethanol | 770 g/l |
| Melting point | 283 °C |
| Boiling point | 732 °C |
| Vapour pressure | <1.33 hpa (428 °C ) |
| Assay | 97.0 – 100.5 | % | |
| Description | Conforms | ||
| Identification | Conforms | ||
| Solubility | Conforms | ||
| Limit of oxychloride | Conforms | ||
| Sulfate | ≤ | 0.03 | % |
| Lead | ≤ | 0.005 | % |
| Alkalies & alkaline earths | ≤ | 1 | % |
| Water | ≤ | 0.5 | % |
| Limit of ammonium salts | Conforms |
Zinc chloride is a white, hygroscopic crystalline salt composed of zinc and chloride ions. It is highly soluble in water and widely used in chemical synthesis, textile processing, metallurgy, and as a fluxing agent due to its strong Lewis acid properties.
🏭⚗️ Production
Zinc chloride is commonly produced by the direct reaction of zinc metal with hydrochloric acid, yielding a solution that can be evaporated to form solid ZnCl₂. It can also be made by reacting zinc oxide or zinc carbonate with hydrochloric acid. For high-purity industrial applications, the compound is purified through repeated crystallization or sublimation.
🔬 Properties
The chemical formula of zinc chloride is ZnCl₂, with a molar mass of approximately 136.29 g/mol. It appears as a white or colorless crystalline solid and is highly hygroscopic, often forming a deliquescent mass in humid air. It has a melting point of about 290 °C and a boiling point around 732 °C. Zinc chloride is very soluble in water, alcohol, glycerol, and ether, and its aqueous solutions are acidic. As a Lewis acid, it is useful in catalyzing various organic reactions.
🧪 Applications
Zinc chloride is used in a wide range of industrial processes. It acts as a flux in soldering and galvanizing by removing oxides from metal surfaces. In organic synthesis, it serves as a catalyst in Friedel–Crafts acylation and other electrophilic substitution reactions. It is used in textile finishing, chemical wood preservation, manufacturing of activated carbon, and as a dehydrating agent. In the pharmaceutical and cosmetic industries, it is sometimes used in dental cements and astringents.
⚠️ Safety
Zinc chloride is corrosive and can cause severe irritation or burns to the skin, eyes, and respiratory tract upon contact. Inhalation of dust or fumes, or ingestion, can be harmful and may result in gastrointestinal or pulmonary damage. Adequate ventilation, protective clothing, gloves, and eye protection should be used during handling. The compound should be stored in a tightly sealed container in a cool, dry environment, away from moisture and incompatible substances such as strong bases.
