1. The problem statement, all variables and given/known data Which of the following, Na3PO4 or C2H4(OH)2 could produce a pH curve with two buffer zones? 3. The attempt at a solution I think the answer is Na3PO4 because it can react twice, but the third reaction may not complete. C2H4(OH)2 is ethylene glycol. Is it possoble for it to react with water to produce a pH curve? Any help would be appreciated.