Friday, 31 March 2017

How to measure a pH solution ?

How to measure a pH solution ?

There are many ways to measure pH :

with a color indicator :  
thymol blue and cresol red :

 with a pH paper :

with the pH meter :

the most precise way to measure pH solution is the pH meter because it measures more precisely than other ways.

Sohail & Anthony


Hard water

Today, we're going to test the hardness of water.
We need some reagents:

We carry out dosage experiment:
 eriochrome turned from pink to blue:

With tap water, we need 1 mL of EDTA
With Hepar water, we need 19 mL of EDTA.
With sea water, we need 75 mL of EDTA

sea water is very very hard!
tap water is not that hard.

Hugo, Mathéo 1STL

Sam at the lab !

Water pH