Thursday, 13 April 2017

Our project is about Orange Juice.

We have make experiment with this orange juice.

 Our leading question is "Why you have to drink quickly an orange juice?"

Our experiments:

-chromatography of sucars

-dosage of glucose

 -dosage vitamine C

 -recuperation and dosage of ethanol

Our projet

TapWater: Titration with EDTA 

       The goal of this titrationwith EDTA is to detect the presence of ion calcium in tapwater. To prove this presence of this ion you must to put on a becker tapwater with indicator and over this becker you put on the buret a solution of EDTA. EDTA react with the ion calcium and the indicator. With the volume equivalent you can calcul the concentration of ion calcium in the tap water.


Make a sound with a light

In this experiment we have made a sound with a light.
We capted the light with a photodiode and we transmite it to a speaker.
 this system is like a wireless system

Project : Biofuels

 Extraction of the oil from sunflower's seeds.

Andony Gatinaud Barberteguy, Vincent Mirailh and Thibaut Latapy are going to talk about an experiment of our project. This experiment consists in extract the oil from the sunflower's seeds.
We have mix 30g of sunflower's seeds with 10mL of cyclohexane. The cyclohexane has the role of solvent in order to extract the linoleic acid contained on the seeds. At the end of this experiment, it stays only cyclohexane and linoleic acid.


Benzoic acid synthesis

Andoni harambillet 
Cyril Cardon 
Kévin Ursuegui 

We carried out the same experiment as presented beneath this quote, with the tools in the lab.
Thanks for watching !

Friday, 7 April 2017


We tested six solutions including :

Sea water, soapy water, hepar, acetic acid, tap water and distilled watter.

We did four experiments.

The first experiment with "cresol red " and our results were:
Sea water we see a yellow precipitate.

Soapy water we see a green precipitate.

Hepar we see a red precipitate.

Acetic acid we see a yellow precipitate.

Tap water we see a yellow precipitate.

Distilled watter we see a green precipitate.

When the precipitate is red the solution is also basic or acid and when the precipitate is yellow the solution is neutral.

After we conduct an experiment with pH meter:
Sea water we see 7.03

Soapy water we see 7.81

Hepar we see 7.82

Acetic acid we see 2.8

Tap water we see 4.53

Distilled watter we see 4.64

We note that the second experiment were more precise than the first experiment.
Accaries Nicolas and Guillemet Yohan

Water pH

We have carried out experiment about pH of the water :

 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. 
Julien ARAMENDI and Dolunay CALHAN

How hard is sea water

 To measure the hardness of sea water we :

- Fill a burette with 0,01 M EDTA.
- Add 10 mL of sea water with a 10 mL pipette and a bulb, to a 250mL erlenmeyer flask, along with 20mL of the ammoniac buffer and 6-8 drops of eriochrome Black T indicator.
- Swirl
-Put a burette above the flask, filling it with EDTA and turn the stopcock to add solution drop by drop. When it's blue, close the stopcock.
-Calculate the equivalent mL of calcium carbonate per L.

Florian.C ~ Tina.L

pH water.

To know the pH of different water samples we use the "cresol red" , it's a simple experiment : we pour different water for example sea water, soapy water, hepar water, acetic acid, tap water, distilles water.


- We have to remove around 5mL of a water sample to a test tube
- Add some drop of cresol red in the test tubes and compare with the pH color indicator.
- Do the same experiment with the thymol blue.

Hard water and soap

Hard water and soap




Pour 5mL of distilled water into each of the empty test tubes ( 2 ).
Add 5g of epsom salts ( magnesium sulfate ) to one of the test tubes.
Stopper or cap and shake the test tube until the epsom salts dissolve.
Add a drop of liquid dish detergent to both test tubes.
Seal the test tubes with their caps or stoppers.
Shake both test tubes

 1STL - 2017

Hard Water

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

We carry out titration:

 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