Followed by Markownikoffs rule.

\(C{{H}_{3}}-C{{H}_{2}}-C\equiv CH+HCl\to \)

\(\begin{matrix}
   C{{H}_{3}}C{{H}_{2}}-C=C{{H}_{2}}  \\
   \,\,\,\,\,\,\,\,\,\,\,|  \\
   \,\,\,\,\,\,\,\,\,\,\,\,\,Cl  \\
\end{matrix}\)  \(\xrightarrow{HI}\)  \(\underset{2\,-\,chloro\,-\,2\,-\,iodo\,bu\tan e}{\mathop{\begin{matrix}
   \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\begin{matrix}
   I  \\
   |  \\
\end{matrix}  \\
   C{{H}_{3}}-C{{H}_{2}}-C-C{{H}_{3}}  \\
   \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|  \\
   \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,Cl  \\
\end{matrix}}}\,\)