Propyne on reaction with water in presence of 40 % sulphuric acid and 1 % mercuric sulphate forms

Step-by-step solution

Propyne undergoes hydration in the presence of dilute sulphuric acid and mercuric sulphate according to Markovnikov's rule. The addition of a water molecule to the triple bond initially yields an unstable enol intermediate, prop-1-en-2-ol. CH₃-C CH + H₂O Hg²⁺, H^+ CH₃-C(OH)=CH₂ The enol intermediate rapidly undergoes tautomerization to form the more stable keto form, propanone. CH₃-C(OH)=CH₂ CH₃-CO-CH₃ Answer: Propanone