pH and indicators

Procedure

1. Label a separate sample of each teacher-provided dilute solution. Keep it away from your mouth and do not smell it directly.
2. Lay a fresh strip of indicator paper on a clean white tile.
3. With a clean dropper, put one sample drop onto the strip.
4. Match the colour to that indicator’s chart. Note the estimated pH and whether the sample is acidic, neutral, or basic.
5. Take a new strip and a clean dropper for each sample. Compare your estimates and discuss how certain they are.

Precautions

1. Wear eye protection and test only dilute samples approved by your teacher.
2. Keep stock solutions free from contamination. Never taste a sample to judge its acidity.