Skip to main content

Calcium Carbide

ADVERTISEMENT
Identification
Molecular formula
CaC2
CAS number
75-20-7
IUPAC name
acetylide
State
State

Calcium carbide is a solid at room temperature. It is sensitive to moisture and reacts upon exposure to air to produce acetylene gas (C2H2) and calcium hydroxide (Ca(OH)2), both of which are gaseous and solid products, respectively, in this exothermic reaction.

Melting point (Celsius)
2 160.00
Melting point (Kelvin)
2 433.00
Boiling point (Celsius)
2 300.00
Boiling point (Kelvin)
2 573.00
General information
Molecular weight
64.10g/mol
Molar mass
64.0990g/mol
Density
2.2200g/cm3
Appearence

Calcium carbide is a grayish-black, rock-like substance. It often appears in more crystalline forms, which can be whitish to pale gray. It has a distinctive earthy smell, reminiscent of garlic or decaying fish, due to impurities in the technical grade product, which release phosphine. Commercially, it is found as unsorted lumps.

Comment on solubility

Solubility of Acetylide Compounds

Acetylide compounds, specifically those containing the acetylide anion (C₂H≡), showcase a variety of solubility characteristics, often influenced by their specific cation and molecular structure. Generally, the solubility of acetylides in water and organic solvents is an important aspect to consider:

  • Water Solubility: Most acetylides, particularly those with metal cations like sodium or potassium, tend to have limited solubility in water. For instance:
    • Sodium acetylide (NaC₂H) and potassium acetylide (KC₂H) are somewhat soluble due to their ionic nature.
    • However, alkyne acetylides that are less ionic may exhibit significantly lower solubility.
  • Organic Solvent Solubility: Many acetylides exhibit better solubility in organic solvents. This includes:
    • Non-polar solvents such as hexane and toluene.
    • Polar aprotic solvents like dimethyl sulfoxide (DMSO) and acetonitrile.
  • Factors Influencing Solubility: The solubility of acetylides can be influenced by several factors:
    • Temperature: Increased temperature generally enhances solubility for many compounds.
    • Position of the alkyne: Terminal acetylides can exhibit different solubility profiles compared to internal ones.
    • Presence of substituents: Electron-withdrawing or donating groups can significantly alter solubility.

In summary, while acetylides display varied solubility based on their structure and the solvents utilized, their general limited solubility in water contrasts with their favorable behavior in organic environments. Understanding these solubility patterns is crucial for their effective application in various chemical processes.

Interesting facts

Interesting Facts about Acetylide

Acetylide refers to a group of chemical compounds containing the acetylide ion, \({\text{C}}_2{\text{H}}^{-}\). These compounds are particularly fascinating due to their unique properties and applications in various fields:

  • Reactivity: Acetylides are known for their strong nucleophilic behavior, making them excellent candidates for a variety of chemical reactions. They readily react with electrophiles, leading to the formation of a wide range of organic compounds.
  • Use in Organic Synthesis: Acetylides are used extensively in organic synthesis, particularly for creating carbon–carbon bonds. They can react with alkyl halides in a process called nucleophilic substitution, allowing chemists to build complex molecular architectures.
  • Combustion and Detonation: Some acetylide compounds exhibit high energy content and can be used in explosives. This capability is utilized in the production of certain types of ammunition and fireworks, where their rapid decomposition releases a significant amount of energy.
  • Applications in Materials Science: Acetylides, particularly when combined with transition metals, can lead to the synthesis of advanced materials, such as polymers and metal-organic frameworks, which have applications in catalysis and gas storage.
  • Historical Significance: The study of acetylides has an interesting historical ebb, with initial discoveries dating back to the early 19th century. These early investigations laid the groundwork for modern organic and inorganic chemistry.

In summary, the field of acetylide chemistry is rich and varied, influencing not just academic research but also industrial applications. As stated by a renowned chemist, "Understanding the behavior of acetylides opens a myriad of possibilities in chemical synthesis and innovation." The ongoing research into their properties continues to shed light on their potential uses across different branches of science.