Question

Acetylene can be obtained by the reaction:
(A) ${\text{HCOOK}}\,\xrightarrow{{Electrolysis}}$
(B) ${\text{CH}}{{\text{I}}_{\text{3}}}\, + \,{\text{Ag}}\,\xrightarrow[\Delta ]{}$
(C) ${\text{C}}{{\text{H}}_{\text{3}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{OH}}\,\xrightarrow[{{\text{443K}}}]{{{\text{Conc}}{\text{.}}{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}}}$
(D) ${\text{B}}{{\text{e}}_{\text{2}}}{\text{C}}\,{\text{ + }}\,{{\text{H}}_{\text{2}}}{\text{O}}\, \to $

Answer 1

Hint: Acetylene is the simplest alkyne and a hydrocarbon. This colourless gas (lower hydrocarbons are inherently gaseous) is commonly used as a fuel and chemical building block. It is generally treated as a solution since it is unstable in its pure form.

Complete answer:
Let us find the correct option, by checking the product of each option.
(A) ${\text{HCOOK}}\,\,{\text{ + }}\,{{\text{H}}_{\text{2}}}{\text{O}}\xrightarrow{{\text{\Delta }}}\,{{\text{H}}_{\text{2}}}\,{\text{ + }}\,{\text{C}}{{\text{O}}_{\text{2}}}\,{\text{ + }}\,{\text{KOH}}$
Potassium formate reacts with water to give hydrogen, Carbon dioxide and Potassium hydroxide.
(B) \[{\text{2CH}}{{\text{I}}_{\text{3}}}\, + \,6{\text{Ag}}\,\xrightarrow[\Delta ]{}\,{\text{CH}}\, \equiv \,{\text{CH}}\, + \,{\text{6AgI}}\]
Iodoform reacts with silver to give acetylene and silver iodide.
(C) ${\text{C}}{{\text{H}}_{\text{3}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{OH}}\,\xrightarrow[{{\text{443K}}}]{{{\text{Conc}}{\text{.}}{{\text{H}}_{\text{2}}}{\text{S}}{{\text{O}}_{\text{4}}}}}\,{\text{C}}{{\text{H}}_{\text{2}}}\, = \,{\text{C}}{{\text{H}}_{\text{2}}}\, + \,{{\text{H}}_{\text{2}}}{\text{O}}$
Ethanol on reacting with concentrated sulphuric acid at ${\text{443}}\,{\text{K}}$gives ethylene and water.
(D) ${\text{B}}{{\text{e}}_{\text{2}}}{\text{C}}\,{\text{ + }}\,{{\text{H}}_{\text{2}}}{\text{O}}\, \to \,{\text{C}}{{\text{H}}_{\text{4}}}\,{\text{ + }}\,{\text{2BeO}}$
Beryllium carbide reacts with water to give methane and beryllium oxide.
Hence, acetylene is obtained by \[{\text{2CH}}{{\text{I}}_{\text{3}}}\, + \,6{\text{Ag}}\,\xrightarrow[\Delta ]{}\,{\text{CH}}\, \equiv \,{\text{CH}}\, + \,{\text{6AgI}}\].
So, the correct option is B.

Additional information:
To prevent accidental leakage and an explosive atmosphere, acetylene cylinders should not be stored in small spaces, enclosed cars, garages, or houses.
Acetylene should not be shipped in copper pipes because copper catalyses the decomposition of acetylene.
Acetylene is also extremely flammable, like most light hydrocarbons, which explains why it's used in welding. Under certain conditions, acetylene can react in an exothermic addition-type reaction to form a variety of products, including benzene and/or vinylacetylene, possibly in addition to carbon and hydrogen.

Note:
While pure acetylene is odourless, impurities in commercial grades give it a distinct odour. Since the two carbon atoms are bonded together in a triple bond, acetylene is unsaturated as an alkyne. Acetylene is not particularly toxic, but it does contain toxic impurities such as traces of phosphine and arsine when made from calcium carbide, giving it a distinct garlic-like odour.