Question

Give the balanced equation for the laboratory preparation of an unsaturated hydrocarbon from Calcium carbide.

Answer 1

Laboratory preparation of an unsaturated hydrocarbon from Calcium carbide.

• Alkynes (unsaturated hydrocarbon with triple bonds) are prepared from Calcium carbide.
• Ethyne$\left({\mathrm{C}}_2{\mathrm{H}}_2\right)$ is prepared by the action of water on Calcium carbide$\left(Ca{C}_2\right)$
• Lumps of Calcium carbide are placed in a flask and water is gradually dropped on it.
• The Ethyne thus evolved, is passed through acidified Copper sulphate$\left(CuS{O}_4\right)$ solution to remove impurities.
• The chemical equation is as follows.

$\underset{(\mathrm{Calcim}\mathrm{carbide})}{{\mathrm{CaC}}_2\left(\mathrm{s}\right)}+\underset{\left(\mathrm{Water}\right)}{2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}\to \underset{\left(\mathrm{Ethyne}\right)}{{\mathrm{C}}_2{\mathrm{H}}_2\left(\mathrm{g}\right)}+\underset{(\mathrm{Calcium}\mathrm{hydroxide})}{\mathrm{Ca}{\left(\mathrm{OH}\right)}_2\left(\mathrm{aq}\right)}$