Indicators and titration curves
In choosing an indicator, it is important to consider where your pH change in your titration curve will occur. There is a range of common laboratory indicators to choose from. A few are shown below with their range and colours.
INSERT [IND_CI_08_ima]
In the titration below (strong acid with a weak base) the wrong indicator has been chosen. You can see that the colour change does not occur with the sharp rise in pH at the equivalence point.
INSERT [IND_CI_09_ima]
Can you choose a suitable indicator for this titration?
Phenolphthalein would be an appropriate choice. Have a look at the chart for others.
The image above has been taken from the Interactive Lab Primer simulation tool which can show titration curves for all sorts of different combinations of weak/strong acid/alkali that can be selected. It allows you to choose an indicator and run it to see if it is a good choice. Have a go.