Lead acetate (Pb(OAc)₂) is a white crystalline compound. It’s used in hair dyes due to its ability to darken hair. However, it poses health risks and must be handled with care.
| IUPAC Name | Lead(II) Acetate |
| Molecular Formula | Pb(OAc)₂ |
| CAS Number | 301-04-2 |
| Synonyms | Lead(II) ethanoate, Plumbous acetate, Lead diacetate |
| InChI | InChI=1S/2C2H4O2.Pb/c21-2(3)4;/h21H3,(H,3,4);/q;;+2/p-2 |
Lead Acetate Properties
Lead Acetate Formula
The chemical formula of lead diacetate is Pb(OAc)₂, where Pb represents the symbol for lead, and OAc denotes the CH₃COO⁻ ion. It is a white crystalline compound with two CH₃COO⁻ ions per lead atom.
Lead Acetate Molar Mass
Lead diacetate has a molar mass of approximately 325.29 g/mol. To calculate this, we add the atomic masses of one Pb atom and two CH₃COO⁻ ions present in its chemical formula.
Lead Acetate Boiling Point
The boiling point of lead diacetate is around 280°C (536°F). When exposed to high temperatures, it undergoes a phase transition from a solid to a liquid state, making it crucial to handle with caution.
Lead Acetate Melting Point
Lead diacetate has a melting point of about 280°C (536°F). At this temperature, the solid compound transforms into a liquid, making it suitable for certain applications like hair dyes.
Lead Acetate Density g/mL
The density of lead diacetate is approximately 3.25 g/mL. This value represents the mass of the compound per unit volume and is important for understanding its physical properties and applications.
Lead Acetate Molecular Weight
The molecular weight of lead diacetate is approximately 325.29 g/mol. It provides essential information for various chemical calculations and helps researchers in understanding its behavior and reactivity.
Lead Acetate Structure
Lead diacetate has a crystalline structure with Pb²⁺ cations coordinated to two CH₃COO⁻ ions. The arrangement of atoms and bonds in the crystal lattice determines its stability and properties.
Lead Acetate Solubility
Lead diacetate is sparingly soluble in water. It dissolves to a limited extent, forming a clear, colorless solution. Its solubility varies with temperature, making it crucial to store and handle appropriately to prevent environmental contamination.
| Appearance | White Crystalline |
| Specific Gravity | ~3.25 g/mL |
| Color | Colorless |
| Odor | Odorless |
| Molar Mass | ~325.29 g/mol |
| Density | ~3.25 g/mL |
| Melting Point | ~280°C (536°F) |
| Boiling Point | ~280°C (536°F) |
| Flash Point | Not Applicable |
| Water Solubility | Sparingly Soluble |
| Solubility | Limited Solubility, varies with temperature |
| Vapour Pressure | Negligible |
| Vapour Density | Not Available |
| pKa | Not Available |
| pH | Not Available |
Lead Acetate Safety and Hazards
Lead diacetate poses significant safety hazards and should be handled with utmost care. It is toxic if ingested, inhaled, or absorbed through the skin. Prolonged exposure can lead to lead poisoning, causing adverse health effects, especially on the nervous system and kidneys. Avoid contact with eyes, skin, and clothing. Use proper ventilation and personal protective equipment when handling. Prevent its release into the environment as it can contaminate soil and water, impacting ecosystems. Keep it away from children and animals. Dispose of it properly according to local regulations. Overall, strict adherence to safety guidelines is crucial to minimize risks.
| Hazard Symbols | Health Hazard, Environmental Hazard |
| Safety Description | Toxic and Harmful to the environment |
| UN IDs | UN1616 |
| HS Code | 29152900 |
| Hazard Class | 6.1 (Toxic Substances) |
| Packing Group | II |
| Toxicity | Highly Toxic |
Lead Acetate Synthesis Methods
There are several methods for synthesizing lead diacetate.
One common approach involves reacting metallic lead with acetic acid. In this method, you typically add lead to a container and slowly pour acetic acid into the vessel while controlling conditions like stirring and regulating temperature. The reaction proceeds, forming lead diacetate as a white precipitate.
Another method involves the reaction of Lead Oxide (PbO) or Lead Carbonate (PbCO₃) with glacial acetic acid. You mix Lead Oxide or Lead Carbonate with acetic acid and heat the mixture, causing a reaction that yields lead diacetate.
An alternative route for synthesis is through the double displacement reaction of Pb(NO₃)₂ with CH3COONa in an aqueous solution. This reaction produces lead diacetate as a precipitate.
It is essential to handle these synthesis methods with caution due to the toxicity of lead compounds. You must follow proper safety measures and conduct the processes in well-ventilated areas with appropriate protective equipment. Also, adherence to waste disposal regulations is crucial to prevent environmental contamination.
Lead Acetate Uses
Lead diacetate finds various applications due to its unique properties. Here are some uses:
- Hair Dye: Certain hair dyes use lead diacetate to gradually darken hair over time. However, due to its toxicity, its use in cosmetic products has been restricted in many countries.
- Laboratory Reagent: It serves as a reagent in laboratories for various chemical reactions and analyses.
- Photography: In the past, photographers used lead diacetate to sensitize photographic films and papers in black-and-white photography.
- Sugar of Lead: Historically, people used lead diacetate, known as “Sugar of Lead,” to preserve wine and other beverages.
- Analytical Chemistry: In analytical chemistry, scientists use lead diacetate to detect the presence of hydrogen sulfide gas.
- Mordant in Dyeing: It acts as a mordant in dyeing and printing textiles.
- Chemical Synthesis: It serves as a precursor for the synthesis of other lead compounds.
Despite its various uses, it is essential to be cautious with lead diacetate due to its high toxicity. Minimize exposure to lead compounds and strictly follow proper safety measures during their handling and disposal to protect human health and the environment. Limit or replace many of its applications with safer alternatives.
Questions:
Q: Is lead II acetate soluble in water?
A: Lead II diacetate is sparingly soluble in water.
Q: Is lead acetate soluble?
A: Lead diacetate is sparingly soluble in water.
Q: Which hair dyes contain lead acetate?
A: In some countries, certain gradual hair dyes contain lead diacetate as an ingredient, although its use is restricted due to toxicity concerns.
Q: Chronic exposure to acetic acid can lead to what disorders?
A: Chronic exposure to acetic acid may cause respiratory and skin irritation.
Q: What is the formula for lead II diacetate?
A: The formula for lead II diacetate is Pb(OAc)₂.
Q: Which lead acetate is used in the Lindlar catalyst?
A: Lead(II) diacetate is not typically used in the Lindlar catalyst; instead, palladium acetate is used.
Q: What is lead acetate?
A: Lead diacetate is a white crystalline compound used in various applications, such as hair dyes and chemical synthesis.
Q: How do I make lead acetate?
A: Lead diacetate can be prepared by reacting metallic lead with acetic acid or through other chemical synthesis methods.
Q: Are there any hair dyes that don’t have lead acetate?
A: Yes, many modern hair dyes do not contain lead diacetate, as its use in cosmetic products has been restricted in many countries due to its toxicity.
Q: Does a reaction occur when aqueous solutions of aluminum iodide and lead(II) acetate are combined?
A: Yes, a reaction occurs, and PbI2 and aluminum acetate are formed as products.
Q: Does sodium chromate and lead(II) acetate react?
A: Yes, a reaction occurs, resulting in the formation of PbCrO4 and sodium acetate.
Q: What chemical reacts with copper(II) sulfate to make blue and with lead(II) acetate to make white?
A: Ammonium hydroxide reacts with copper(II) sulfate to form blue precipitates (copper hydroxide). In contrast, hydrogen sulfide reacts with lead(II) diacetate to create white lead sulfide.