Zinc chloride (ZnCl2) is a white, crystalline compound. It’s used in various industrial applications like soldering fluxes, chemical synthesis, and galvanizing. It’s highly soluble in water.
| IUPAC Name | Zinc chloride |
| Molecular Formula | ZnCl2 |
| CAS Number | 7646-85-7 |
| Synonyms | Butter of zinc; Zinc dichloride; Zinc (II) chloride; Zinc butter; C.I. 77043 |
| InChI | InChI=1S/2ClH.Zn/h2*1H;/q;;+2/p-2 |
Zinc Chloride Properties
Zinc Chloride Formula
The chemical formula of zinc dichloride is ZnCl2. It is composed of one zinc (Zn) atom and two chlorine (Cl) atoms. This ionic compound forms a white, crystalline solid with a distinct structure.
Zinc Chloride Molar Mass
The molar mass of zinc dichloride is approximately 136.29 grams per mole (g/mol). It is derived from the sum of the atomic masses of one zinc atom and two chlorine atoms.
Zinc Chloride Boiling Point
Zinc dichloride has a relatively high boiling point of around 732 degrees Celsius (C) or 1350 degrees Fahrenheit (F). At this temperature, it transforms from a liquid to a gaseous state.
Zinc Chloride Melting Point
The melting point of zinc dichloride is approximately 290 degrees Celsius (C) or 554 degrees Fahrenheit (F). At this temperature, the solid zinc dichloride changes into a liquid state.
Zinc Chloride Density g/mL
The density of zinc dichloride is about 2.91 grams per milliliter (g/mL) at room temperature. This property describes its mass per unit volume.
Zinc Chloride Molecular Weight
The molecular weight of zinc dichloride, calculated from its chemical formula, is approximately 136.29 g/mol. This value represents the sum of the atomic weights of its constituent atoms.
Zinc Chloride Structure
Zinc dichloride features a crystal lattice structure with Zn2+ cations and Cl- anions held together by ionic bonds. The arrangement forms a stable and orderly three-dimensional lattice.
Zinc Chloride Solubility
Zinc dichloride is highly soluble in water, which means it readily dissolves in the presence of water molecules. This property contributes to its widespread use in various industrial applications and chemical processes.
| Appearance | White crystalline solid |
| Specific Gravity | 2.91 g/mL |
| Color | Colorless |
| Odor | Odorless |
| Molar Mass | 136.29 g/mol |
| Density | 2.91 g/cm³ |
| Melting Point | 290°C (554°F) |
| Boiling Point | 732°C (1350°F) |
| Flash Point | Not applicable |
| Water Solubility | Highly soluble in water |
| Solubility | Soluble in organic solvents such as alcohol and acetone |
| Vapour Pressure | 1 mmHg at 359°C |
| Vapour Density | 5.4 (air = 1) |
| pKa | -1.9 |
| pH | ~5 (0.1 M solution in water) |
Zinc Chloride Safety and Hazards
Zinc dichloride poses certain safety hazards that require careful handling. Direct contact with skin or eyes can cause irritation and burns. Inhalation of its fumes can irritate the respiratory system. It is essential to wear protective gear such as gloves and goggles when handling the compound. Moreover, it should be stored in a well-ventilated area away from incompatible substances. In case of accidental ingestion or exposure, seek immediate medical attention. Avoid releasing it into the environment, as it can be harmful to aquatic life. By following proper safety measures and guidelines, the risks associated with zinc dichloride can be minimized effectively.
| Hazard Symbols | Corrosive (C); Harmful (Xn) |
| Safety Description | Avoid contact with skin and eyes. Use in a well-ventilated area. Wear protective gloves and goggles. In case of contact or ingestion, seek medical attention. Do not release to the environment. Keep away from incompatible substances. |
| UN IDs | UN 2331 (Zinc dichloride, anhydrous); UN 2332 (Zinc dichloride, solution) |
| HS Code | 28273990 |
| Hazard Class | 8 (Corrosive substances) |
| Packing Group | II (Medium danger) |
| Toxicity | Harmful if ingested or inhaled. |
Zinc Chloride Synthesis Methods
Various methods allow the synthesis of zinc dichloride.
One common approach involves the reaction of zinc oxide (ZnO) with hydrochloric acid (HCl). In this method, a chemist slowly adds ZnO to a solution of HCl while continuously stirring. The reaction produces zinc dichloride and water as byproducts. Another method is the direct combination of zinc metal with chlorine gas (Cl2). This reaction requires careful control of temperature and pressure to ensure a successful outcome.
An alternative process involves dissolving zinc metal in HCl solution, which results in the formation of zinc dichloride and hydrogen gas (H2). Treating HCl with zinc carbonate (ZnCO3) or zinc hydroxide (Zn(OH)2) produces zinc dichloride, water, and carbon dioxide (CO2) as byproducts.
Zinc sulfate (ZnSO4) and barium chloride (BaCl2) undergo a double decomposition reaction to yield zinc dichloride along with the formation of barium sulfate (BaSO4). By mixing these two compounds, zinc dichloride precipitates out, while barium sulfate (BaSO4) remains in the solution.
Each of these methods provides a route for the synthesis of zinc dichloride, and the choice of method depends on factors such as the availability of reagents, reaction conditions, and the desired purity of the final product.
Zinc Chloride Uses
Zinc dichloride finds a wide range of applications across various industries due to its versatile properties. Here are some prominent uses of zinc dichloride:
- Galvanizing: Zinc dichloride serves as a vital component in the galvanizing process to prevent corrosion of metals like steel and iron. It forms a protective zinc coating, enhancing their longevity and durability.
- Soldering Flux: In soldering operations, zinc dichloride acts as a flux to remove metal oxides from the surface of metals, ensuring better adhesion and a strong bond between solder and metal.
- Chemical Synthesis: It serves as a catalyst or reagent in numerous chemical reactions, such as the Friedel-Crafts acylation and dehydrations.
- Wood Preservation: Wood preservative applications utilize zinc dichloride to safeguard timber from fungal and insect decay, thus extending its lifespan.
- Textile Processing: In the textile industry, it aids in the production of mercerized cotton fabric, imparting desirable properties like increased luster and improved strength.
- Battery Electrolyte: Zinc dichloride acts as an electrolyte in certain batteries, such as the zinc-carbon battery, helping to facilitate the flow of ions between electrodes.
- Deodorant and Antiperspirant: It is a common ingredient in antiperspirants due to its astringent properties that help reduce sweat production and control body odor.
- Pharmaceuticals: Zinc dichloride finds application in various pharmaceutical formulations, particularly in mouthwashes, throat lozenges, and topical antiseptic solutions.
- Dyeing Industry: The dyeing industry employs zinc dichloride as a mordant in the dyeing process to enhance the colorfastness of fabrics with dyes.
- Adhesive Formulations: Manufacturers incorporate zinc dichloride in adhesive formulations to enhance the bonding properties of glues and cements.
The versatility of zinc dichloride makes it an essential compound in numerous industrial processes and everyday products, contributing to the advancement of several key industries.
Questions:
Q: Is ZnCl2 soluble in water?
A: Yes, ZnCl2 is highly soluble in water.
Q: What is the net ionic equation of the reaction of ZnCl2 with NaOH?
A: The net ionic equation is Zn²⁺(aq) + 2OH⁻(aq) → Zn(OH)₂(s).
Q: Is ZnCl2 soluble?
A: Yes, ZnCl2 is soluble in water.
Q: Is ZnCl2 ionic or molecular?
A: ZnCl2 is an ionic compound.
Q: What type of bonding occurs in zinc(II) chloride, ZnCl2?
A: Ionic bonding occurs in ZnCl2.
Q: Which change could decrease the rate of production of ZnCl2?
A: Lowering the temperature of the reaction could decrease the rate of ZnCl2 production.
Q: Is ZnCl2 solid?
A: Yes, ZnCl2 is a solid at room temperature.
Q: Is ZnCl2 a salt?
A: Yes, ZnCl2 is considered a salt.
Q: How will you obtain zinc chloride from zinc?
A: Reacting zinc with hydrochloric acid will produce zinc chloride.
Q: What is the formula of zinc chloride?
A: The formula of zinc chloride is ZnCl2.
Q: Are zinc chloride batteries harmful to the earth?
A: Yes, zinc chloride batteries can be harmful to the environment if not properly disposed of.
Q: What is the molar mass of zinc chloride?
A: The molar mass of zinc chloride is approximately 136.29 g/mol.