The reaction sequence provided is as follows:

C2H5OH $ethanol$ undergoes dehydration to form C2H4 $ethylene$ by losing a water molecule.

C2H4 $ethylene$ reacts with HCl to form C2H5Cl $chloroethane$ by adding a chlorine molecule.

C2H5Cl $chloroethane$ undergoes hydrolysis to form C2H5OH $ethanol$ by breaking the C-Cl bond and replacing it with an -OH group.

C2H5OH $ethanol$ reacts with NaOH $sodiumhydroxide$ to form C2H5ONa $sodiumethoxide$ by replacing an -OH group with a sodium ion.