c
Reaction of \(HgSO _{4} / dil H _{2} SO _{4}\) with alkyne gives addition of water as per markonikoff's rule.

\((1)\) \(HC \equiv CH\) \(\xrightarrow[{{H_2}S{O_4}}]{{HgS{O_4}}}\) \(\begin{array}{*{20}{c}} {\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,O} \\ {\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,||} \\ {C{H_2} - CH \rightleftharpoons C{H_3} - CH} \\ {|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ {OH\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \end{array}\)

\((2)\) \([Image]\)

\((3)\,CH_3-C\equiv CH\) \(\xrightarrow[{{H_2}S{O_4}}]{{HgS{O_4}}}\) \(\begin{array}{*{20}{c}} {\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,O} \\ {\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,||} \\ {C{H_3} - C = C{H_2} \rightleftharpoons C{H_3} - C - C{H_3}} \\ {|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ {OH\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \end{array}\)

\((4)\) \((4)\,CH_3-C\equiv C-CH_3\) \(\xrightarrow[{{H_2}S{O_4}}]{{HgS{O_4}}}\) \(\begin{array}{*{20}{c}} {C{H_3} - C = CH - C{H_3}} \\ {|\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ {OH\,\,\,\,\,\,\,\,\,} \end{array}\) \(\Updownarrow\) \(\begin{array}{*{20}{c}}
  {C{H_3} - C - C{H_2} - C{H_3}} \\ 
  {||\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ 
  {O\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} 
\end{array}\)