From lime stone CaO quicklime Ca2 is produced while CO2 is used in {HEAD ~ the production} of {TAIL ~ soda} 
of
From lime stone CaO quicklime Ca2 is produced while CO2 is used in { HEAD ~ the production } of { TAIL ~ soda }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL