A chemist performs an acid–base titration using 0.176 M aqueous NaOH as the titrant with 26.15 mL of 0.102 M H2SO4. The endpoint of the titration is detected using phenolphthalein as the indicator.
Some acid–base indicators are listed along with their pKa values. Which indicators would be most suitable for monitoring a titration involving a strong acid and a strong base?
Choose one or more:
bromothymol blue; pKa = 6.8
methyl yellow; pKa = 3.5
phenol red; pKa = 7.2
alizarine yellow; pKa = 11.0
phenolpthalein; pKa = 9.2
I would say bromothymol blue and phenol red but i am not sure any thoughts?
1 answer
Yes, either of those indicators would be suitable for a pH of 7.0, that is, titration of strong acid with strong base.
1 answer