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

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

Hugo, Mathéo 1STL

Sam at the lab !

Water pH

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