{TAIL ~ The aqueous solution} of sodium hydroxide, which is the heavier phase, contains most of {HEAD ~ the catalyst} 
{ TAIL ~ The aqueous solution } of sodium hydroxide , which is the heavier phase , contains most of { HEAD ~ the catalyst }
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD