Chem indicator question

Hi guys, how do you use the pKin values for the indicators?

This question is about an experiment to determine the equilibrium constant, Kc
, for
the reaction between ethanoic acid and ethanol to form ethyl ethanoate and water.
Two sealed test tubes were prepared.
The first test tube contained 0.0400 mol ethanoic acid, 0.0400 mol of ethanol and
0.20 cm3
of concentrated hydrochloric acid.
The second test tube contained 0.0400 mol ethyl ethanoate, 0.0400 mol of water and
0.20 cm3
of concentrated hydrochloric acid.
After standing at 25°C for two weeks, to ensure equilibrium is reached, the contents
of each test tube were separately titrated with 0.200 mol dm–3 sodium hydroxide
solution.
0.20 cm3
of concentrated hydrochloric acid was also titrated with the same sodium
hydroxide solution.

How do you establish the best indicator to use?


Many thanks btw