py : ▁ 1 , 6 7 5 ▁k J / kg ) ▁and ▁requires ▁exact ▁maintenance ▁of ▁temperature ▁and ▁p H ▁during ▁the ▁hydro ly s is . ▁When ▁calci um ▁hydro x ide ▁is ▁used ▁as ▁the ▁hydro ly s is ▁medium , ▁a ▁solution ▁of ▁calci um ▁vin yl ▁sul fon ate ▁is ▁obtained . ▁Ac id ification ▁of ▁this ▁hydro ly s is ▁mixture ▁with ▁sul fur ic ▁acid ▁gives ▁vin yl s ulf onic ▁acid , ▁together ▁with ▁the ▁poor ly ▁sol ub le ▁calci um ▁sul f ate . ▁ ▁Vin yl s ulf onic ▁acid ▁also ▁can ▁be ▁prepared ▁by ▁de h yd r ation ▁of ▁is eth ionic ▁acid ▁with ▁ph osph orus ▁pent ox ide : ▁ ▁Vin yl s ulf onic ▁acid ▁can ▁also ▁be ▁prepared ▁by ▁sul fo ch lor ination ▁of ▁ch lor o eth ane , ▁de h ydro hal ogen ation ▁to ▁vin yl s ul fony l ▁ch lor ide ▁and ▁subsequent ▁hydro ly s is ▁of ▁the ▁acid ▁ch lor ide . ▁ ▁Use ▁ ▁The ▁activ ated ▁C = C ▁double ▁bond ▁of ▁vin yl s ulf onic ▁acid ▁react s ▁readily ▁with ▁nucle oph iles ▁in ▁an ▁addition ▁reaction . ▁ 2 - A min o eth anes ulf onic ▁acid ▁is ▁formed ▁with ▁am mon ia ▁and ▁ 2 - m eth yl am ino eth anes ulf onic ▁acid ▁with ▁m eth yl am ine . ▁ ▁Vin yl s ulf onic ▁acid