text: Terminal alkynes are weak acids:
  : RC≡CH + R″M  R″H + RC≡CM
  To generate acetylides from acetylene and alkynes relies on the use of  organometallic or inorganic superbases in solvents which are less acidic than the terminal alkyne.  In early studies liquid ammonia was employed, but ethereal solvents are more common.
  Lithium amide, LiHMDS, or organolithium reagents, such as butyllithium, are frequently used to form lithium acetylides:
  Monopotassium and monosodium acetylide can be prepared from various inorganic reagents (such as sodium amide) or from their elemental metals, often at room temperature and atmospheric pressure.
  Copper(I) acetylide can be prepared by passing acetylene through an aqueous solution of copper(I) chloride because of a low solubility equilibrium. Similarly, silver acetylides can be obtained from silver nitrate.
  Calcium carbide is prepared by heating carbon with lime (calcium oxide) at approximately 2,000 °C. A similar process is used to produce lithium carbide.