Estimation of pH - Determining Color Change Regions

Part 1: Determining Indicator Color Change Regions

Identify the color change region(s) for each of these nine indicators. Make sure to record both the pH of the change (it should be 2 - 4 pH units) and the color before, during and after each of the changes. Remember that some indicators may have more than one color change region. Each of the links below takes you to a page that has 13 test tubes containing buffers with pH's from 1 to 13. To each has been added 2 - 4 drops of referenced indicator.

Phenolphthalein Bromothymol Blue Methyl Orange
Thymolphthalein Thymol Blue Methyl Red
Malachite Green Bromocresol Purple Bromocresol Green

Continue on and perform part 2.

introduction background prelab experiment postlab