Protocol : Pour 1 mL of each water in test tubes, then measure the pH with this different techniques : color indicator like Cresol Red or Tymol blue, pH paper and pH meter.
Test tubes contain :
1 : Sea water 2 : Soapy water 3 : Hepar water
4 : Acetic acid 5 : Tap water 6 : Distilled water
- First we have measured the pH of different water with the Cresol red
- Then we have measured with the Tymol blue
- After that we have used pH paper
- And at the end we carried out experiment with the pH meter
The results with pH meter are more precise than others.