At higher temperature, Ethyne on reaction with water in the presence of HgSO4 and H2SO4 gives:
Correct answer: B. Acetaldehyde
- A. Acetone
- B. Acetaldehyde
- C. Acetic acid
- D. Ethyl alcohol
Explanation
Water adds across ethyne in the presence of HgSO4 and H2SO4 to form an unstable enol, CH2=CHOH. This enol undergoes keto-enol tautomerism to give the more stable aldehyde ethanal, CH3CHO, also called acetaldehyde. The likely mistake is choosing ethyl alcohol because water adds to the triple bond, but the mercury-catalysed hydration ultimately produces a carbonyl compound, not an alcohol.
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About Alkynes
Alkynes are unsaturated hydrocarbons containing a carbon-carbon triple bond, with sp-hybridised carbon atoms and a linear arrangement around the bond. The content includes nomenclature, preparation, acidity of terminal alkynes, and addition reactions with hydrogen, halogens, hydrogen halides and water, as well as oxidation.
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