🤓 Based on our data, we think this question is relevant for Professor Kruger's class at UNG.
We have to determine a suitable indicator to determine the pH of the given solution.
Indicators are weak acids/bases. The pH at which an indicator changes color is determined by its pKIn value.
The pH range for color change of phenolphthalein is 8.2 – 10.0.
Phenolphthalein has pKIn = 9.4 and it changes to red at pH values higher than 9.4.
Bromothymol blue has pKIn = 7.0 and it changes to from yellow to blue in the pH range of 6.0 – 7.6.
Addition of phenolphthalein to an unknown colorless solution does not cause a color change. The addition of bromthymol blue to the same solution leads to a yellow color.
What other indicator or indicators would you want to use to determine the pH of the solution more precisely?