The best indicator to use for the titration of ethanoic acid with sodium hydroxide is

A.

methyl orange

B.

phenolphthalein

C.

screened methyl orange

D.

methyl red

Correct answer is B

Phenolphthalein is an indicator that is commonly used in acid-base titrations. It is colorless in acidic solutions (pH below 8.2) and turns pink or magenta in alkaline solutions (pH above 10). In the titration of ethanoic acid (acetic acid) with sodium hydroxide (a strong base), the pH will change from acidic to alkaline as the acid is neutralized by the base