Phenolphthalein indicator?

Question

I am going to titrate ethyl ethanoate and sodium hydroxide, i think i have to use Phenolphthalein indicator, what colour change will it go from when i put it in the ethyl ethanoate and to when i neutralise it with sodium hydroxide?

I've researched this experiment from a book but it doesn't mention the reaction being slow, it does not mention the use of an acid catalyst because it would affect the amount i would use in the titration to neutralise? Are you certain that the reaction is slow :S

Answer 1

Phenolphthalein is a sensitive chemical with the formula C20H14O4 (often written as "HIn" in shorthand notation). Often used in titrations, it turns colorless in acidic solutions (less then 8.2) and pink in basic solutions (between 8.2 qnd 10). If the concentration of indicator is particularly strong and in alkaline conditions, it can appear reddish purple at a pH greater than 10.. In solutions containing a pH below 0, phenolphthalein turns a bright orange color.



In strongly basic solutions, phenolphthalein's pink color undergoes a rather slow fading reaction and becomes colorless again. In other words, the molecule has four forms.

Answer 2

Ethyl ethanoate only reacts very slowly with sodium hydroxide, so I doubt whether you are going to react them together in a titration. Phenolphthalein is colourless in acid, and pink in excess alkali.
You are probably going to add an acid catalyst to the ethyl ethanoate, and measure how quickly the total amount of acid increases, as ethanoic acid is gradually formed.