Gold chloride (AuCl3) is a compound formed by combining gold with chlorine. It is used in various applications, including gold plating and as a catalyst in chemical reactions.
| IUPAC Name | Gold(III) chloride |
| Molecular Formula | AuCl3 |
| CAS Number | 13453-07-1 |
| Synonyms | Auric chloride, Trichlorogold, Gold trichloride |
| InChI | InChI=1S/3ClH.Au/h3*1H;/q;;;+3/p-3 |
Gold Chloride Properties
Gold Chloride Formula
The formula of gold trichloride is AuCl3. It is a chemical compound composed of one atom of gold (Au) and three atoms of chlorine (Cl). This formula represents the stoichiometry of the elements present in gold trichloride.
Gold Chloride Molar Mass
The molar mass of gold trichloride is calculated by adding the atomic masses of its constituent elements. For gold trichloride (AuCl3), the molar mass is approximately 303.33 g/mol. It is useful in determining the amount of substance in a given sample.
Gold Chloride Boiling Point
Gold trichloride has a boiling point of around 254 °C (degrees Celsius). At this temperature, the compound transitions from a liquid to a gaseous state. The boiling point indicates the temperature at which the vapor pressure of the liquid equals the atmospheric pressure.
Gold Chloride Melting Point
The melting point of gold trichloride is about 254 °C (degrees Celsius). It is the temperature at which the solid form of the compound changes into a liquid. Understanding the melting point is essential in various industrial processes.
Gold Chloride Density g/mL
The density of gold trichloride is approximately 4.7 g/mL (grams per milliliter). Density is the measure of mass per unit volume of a substance. Gold trichloride’s relatively high density makes it heavier than water.
Gold Chloride Molecular Weight
The molecular weight of gold trichloride, also known as the molar mass, is about 303.33 g/mol (grams per mole). It is the sum of the atomic weights of all the atoms in the compound. Molecular weight is crucial in chemical calculations.
Gold Chloride Structure
Gold trichloride (AuCl3) has a molecular structure consisting of one gold atom bonded to three chlorine atoms. The arrangement forms a trigonal planar shape, with the gold atom at the center and the chlorine atoms surrounding it.
Gold Chloride Solubility
Gold trichloride exhibits limited solubility in water. It dissolves better in certain organic solvents, such as ethanol and chloroform. The solubility of gold trichloride is influenced by factors like temperature and the nature of the solvent.
| Appearance | Yellowish solid |
| Specific Gravity | ~4.7 g/mL |
| Color | Yellow |
| Odor | Odorless |
| Molar Mass | ~303.33 g/mol |
| Density | ~4.7 g/mL |
| Melting Point | ~254 °C |
| Boiling Point | ~254 °C |
| Flash Point | Not applicable |
| Water Solubility | Limited solubility |
| Solubility | Soluble in some organic solvents such as ethanol and chloroform |
| Vapor Pressure | Not available |
| Vapor Density | Not available |
| pKa | Not available |
| pH | Neutral (pH 7) |
Gold Chloride Safety and Hazards
Gold trichloride poses potential safety hazards and requires careful handling. It is essential to wear appropriate protective gear, such as gloves and safety goggles, to avoid skin contact and eye irritation. Inhaling its dust or vapors should be avoided due to potential respiratory issues. Additionally, exposure to high temperatures can lead to the release of toxic chlorine gas. The compound is also incompatible with strong reducing agents, which can result in hazardous reactions. Proper storage, labeling, and containment measures are necessary to prevent accidents. Understanding these hazards and safety precautions is crucial when working with gold trichloride in laboratory or industrial settings.
| Hazard Symbols | Danger |
| Safety Description | Handle with care. Avoid skin and eye contact. Do not inhale dust or vapors. Keep away from strong reducing agents. |
| UN IDs | Not available |
| HS Code | 2843.29 |
| Hazard Class | 6.1 (Toxic substances) |
| Packing Group | II |
| Toxicity | Highly toxic if ingested or inhaled. Can cause skin and eye irritation. |
Gold Chloride Synthesis Methods
Several methods enable the synthesis of gold trichloride.
One common approach involves dissolving gold metal or gold oxide in hydrochloric acid (HCl). The reaction produces gold trichloride and water. Another method involves reacting gold with chlorine gas, forming gold trichloride directly. Alternatively, chlorine gas can react with gold metal in the presence of a catalyst like iron chloride, yielding gold trichloride and iron chloride as byproducts.
Another synthesis route involves reacting gold metal with aqua regia, a mixture of concentrated nitric acid (HNO3) and hydrochloric acid. Aqua regia’s powerful oxidizing properties convert gold to gold trichloride, which can be isolated through evaporation. Gold trichloride forms when hydrochloric acid reacts with gold(III) oxide (Au2O3), producing gold trichloride and water.
Various reducing agents, like tin(II) chloride (SnCl2) or sulfur dioxide (SO2), can actively reduce gold(V) chloride (AuCl5) to synthesize gold trichloride. The reaction produces gold trichloride and the respective reducing agent’s chloride.
Each method has its advantages and applicability, depending on the starting materials available and the desired purity of the gold trichloride. Careful consideration of the reaction conditions and safety measures is crucial during the synthesis process.
Gold Chloride Uses
Gold trichloride finds various applications due to its unique properties:
- Gold Plating: Gold trichloride serves as a source of gold ions for electroplating processes, allowing the deposition of a thin layer of gold onto surfaces. This enhances conductivity and provides an attractive, corrosion-resistant finish.
- Catalyst: Gold trichloride acts as a catalyst in various chemical reactions, particularly in organic synthesis. Its ability to activate certain bonds makes it valuable in promoting specific reactions.
- Medicine: Researchers have explored gold trichloride-based compounds for potential therapeutic applications in treating arthritis and other inflammatory conditions.
- Photography: In photography, gold trichloride serves as a toner, imparting purple and brown colors to black and white prints.
- Glass and Ceramics: The glass industry employs gold trichloride to produce ruby glass, giving it a red color, and ceramics benefit from its use to enhance coloration.
- Nanotechnology: Gold trichloride plays a crucial role in nanotechnology by facilitating the synthesis of gold nanoparticles, which have applications in electronics, catalysis, and medical imaging.
- Antibacterial Agent: Gold trichloride nanoparticles have demonstrated promise as antibacterial agents, effectively inhibiting the growth of certain bacteria.
- Art Conservation: In art restoration, experts utilize gold trichloride for gilding and recreating historical pigments.
- Laboratory Reagent: Scientists use it as a laboratory reagent for various chemical analyses and research purposes.
- Metallic Inks: Manufacturers employ gold trichloride-based inks for printing purposes, infusing products like stationery and packaging with a touch of luxury.
Due to its versatility and unique properties, gold trichloride continues to be relevant in diverse industries, playing a significant role in technology, art, medicine, and materials science.
Questions:
Q: What chemical can I use to precipitate the gold out of gold chloride?
A: Sodium metabisulfite (Na2S2O5) can be used as a reducing agent to precipitate gold from gold trichloride solutions.
Q: Is monatomic gold in gold chloride?
A: No, monatomic gold is not gold trichloride; it is a separate form of gold consisting of individual atoms, not in a compound state.
Q: What is the molar mass of gold III chloride?
A: The molar mass of gold III trichloride (AuCl3) is approximately 303.33 g/mol.
Q: What is gold chloride?
A: Gold trichloride (AuCl3) is a chemical compound formed by combining gold with chlorine, used in various applications such as gold plating and catalysis.
Q: How to make stannous chloride for testing gold?
A: Stannous chloride (SnCl2) can be prepared by dissolving tin metal in hydrochloric acid (HCl) followed by reduction.
Q: What is the molar mass of AuCl3?
A: The molar mass of AuCl3 (gold III trichloride) is about 303.33 g/mol.
Q: What is the percentage of gold in AuCl3?
A: The percentage of gold in AuCl3 is approximately 42.49%.
Q: How many moles of H2O are in 3.4 g of AuCl3 · 2 H2O?
A: There are 0.0349 moles of H2O in 3.4 g of AuCl3 · 2 H2O.
Q: Is AuCl3 soluble in water?
A: Yes, AuCl3 (gold III trichloride) is soluble in water to some extent.
Q: How many grams of gold can be recovered from 35 g of AuCl3?
A: Approximately 14.87 grams of gold can be recovered from 35 g of AuCl3.
Q: What is the molar solubility of AuCl3? Ksp = 3.2 × 10−25
A: The molar solubility of AuCl3, given Ksp = 3.2 × 10−25, is approximately 1.8 × 10^-9 mol/L.