b
\(\begin{array}{*{20}{c}}
  {O\,\,\,\,\,\,\,\,\,\,\,} \\ 
  {||\,\,\,\,\,\,\,\,\,\,\,} \\ 
  {Cl - C - O{C_2}{H_5}} 
\end{array}\, + \,\,C{H_3}MgI\, \to \left[ {\begin{array}{*{20}{c}}
  {OMgI\,} \\ 
  {|\,\,\,\,\,\,\,\,\,\,\,} \\ 
  {Cl - C - O{C_2}{H_5}} \\ 
  {|\,\,\,\,\,\,\,\,\,\,\,\,} \\ 
  {C{H_3}\,\,\,\,\,\,} 
\end{array}} \right]\)

ઇથાઇલ ક્લોરો ફોર્મેટ      મિથાઇલ મેગ્નેશિયમ આયોનાઇડ

\(​\xrightarrow{{{H_2}O/{H^ + }}} \begin{array}{*{20}{c}}
  {Cl} \\ 
  {Br} 
\end{array} > Mg+ \, \begin{array}{*{20}{c}}
  {O\,\,\,\,\,\,\,} \\ 
  {||\,\,\,\,\,\,} \\ 
  {C{H_3} - C - O{C_2}{H_5}} 
\end{array}\,\)