 from about 10 mole percent to {HEAD ~ about 25 mole percent} of {TAIL ~ the ampholytic ion pair} 
of
from about 10 mole percent to { HEAD ~ about 25 mole percent } of { TAIL ~ the ampholytic ion pair }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL