Question

Suppose a student performed the titration, but the solution never turned pink. Check all the possible explanations. The student forgot to add phenolphthalein. The student added too much phenolphthalein. The student was not patient enough. The student used HCl as both the analyte and the titrant. The student used NaOH as both the analyte and the titrant.

Answer 1

The answer is The student forgot to add phenolphthalein. 
Phenolphthalein is a chemical compound with the formula C20H14O4 and is often written as "HIn" or "phph" in shorthand notation. Phenolphthalein is often used as an indicator in acid–base titrations. For this application, it turns colorless in acidic solutions and pink in basic solutions.

Answer 2

The answers on E2020 are A, C, and D. I hope this helps.