ઇથાઇન  $\xrightarrow[\begin{smallmatrix} 
 (2)\,\,excess\,I-\,C{{H}_{2}}\,-\,{{(C{{H}_{2}})}_{2}}-\,C{{H}_{3}} \\ 
 (3)\,\,{{H}^{\oplus }} 
\end{smallmatrix}]{(1)\,\,excess\,NaN{{H}_{2}}}$

${H_2}C = CH - CH = C{H_2}\xrightarrow[{0{\,^o}C}]{{HBr}}$ $\begin{array}{*{20}{c}}
  {{H_2}C = CH - CH - C{H_3}} \\ 
  {\,\,\,\,\,\,\,\,\,\,\,|} \\ 
  {\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,Br\,\,\,\,\,\,} 
\end{array}\xrightarrow{{ + 25{\,^o}C}}$ $\begin{array}{*{20}{c}}
  {C{H_2}CH = CHC{H_3}} \\ 
  {|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ 
  {Br\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} 
\end{array}$

આ   $......1......$ નીચા તાપમાને નિયંત્રણ અને  $......2......$  ઉચ્ચ તાપમાન પર નિયંત્રણનું ઉદાહરણ પ્રદાન કરે છે.