The stability of the compounds used and the boiling point difference is such {HEAD ~ that complete recovery} is obtainable by {TAIL ~ a simple distillation} and the amount required for make up is small 
The stability of the compounds used and the boiling point difference is such { HEAD ~ that complete recovery } is obtainable by { TAIL ~ a simple distillation } and the amount required for make up is small
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH