b)      Explain the procedure 

c)       make a scheme 

d)      Note your results 

e)      Make a conclusion : did your experiment give your the answer of your question? If no, explain problems, …

f)       what could you do to improve your experiment ? OR what other experiment could you do?1)      Prepare a report        a) Note the goal of your experiment  (the question you want to answer)

 B) To verify our answer, we checked some web site about volcanoes and propose our experiment to see what is shooting out the lava from the magma chamber.

 We made a supposition in which a lot of gas keep and increase the pressure, like a pressure cooker, and then, the lava blow up very powerfuly.

 To confirm our supposition, we made an experimentation with a flak, a tube, a device to mesure pressure, a lid, some vinegar, some bicarbonate and some dye.

 

C) (see the video at the bottom of the page)

D) Wee saw through our experimentation that the gas made by the reaction until vinegar and bicarbonate make some pressure in the flask and that pressure rises a lot : from 998.2 hPa to 1300.4 hPa. It shows to us that, in the volacanoes, there is gas and that he is very powerful. 

E) To conclue and after some research, we saw that the pressure rises in the magma chamber (through the experimentation with the flask). Finally, we saw (throught web sites) that our supposition was right but only for the explosive volcanoes.

 F) To acheive our research, we could do an experimentation with a more liquid « lava » to show how the effusive vlocanoes are working.

 b)      For our experiment we put 10mL of commercial orange juice with 20mL of water in a beaker. We put 10mL of freshly squeezed orange juice with 20mL of water. We put 3mL of starch in each beaker and we mixed with magnetic stirrer. After that we put the diode solution drop by drop in the two oranges juices with graduated burette. The solution has changed color ; the color move to yellow to black.

 c)       Look at the picture at the bottom of the page

 
d)      For the freshly squeezed orange juice the color has changed after pouring 12,4 mL of diode solution into the beaker. 

For the commercial orange juice the color has changed after pouring 9,8 mL of diode solution into the beaker.

The formula to find the mass of vitamin C is 0,88 x V. 

0,88 x 12,4 = 10,912 mg

There are 10,912 mg of vitamin C in the freshly squeezed orange juice.

0,88 x 9,8 = 8,624

There are 8,624 mg of vitamin C in the commercial orange juice.

 

e)      With our experiment we found that there is more vitamin C in the freshly squeezed orange juice. 

 
f)        We could do an experiment to know how many vitamin C there are in one orange. 

Equipment for this experiment :

-a few deciliters of alcohol vinegar 

-potassium permanganate

-a glass jar

-a pipette

-a filter

How to melt ice ? 

 B° When we started this science project our first idea was to answer the question 

How are sanitary protections dangerous to our health ? 

But to answer this question, we would have needed a lot of differents chemicals that were practically impossible to get because of their dangerousness.

So we switch to another project : How soap (shampoo,…) can clean our body ?

But at the last minute, we change to another project and this is the final one :

How to melt ice ?

 C° To answer this question, we used only 7 objects:

- ice cubes

- salt 

- sugar

- a small refrigerator

- a cristalysor

- a small spatula

- a twine

 We took some ice cube out of the small refrigerator to put them in the cristalysor, then with the spatula we took some salt tto put it on the ice cube, put the twine on the melting ice and put it back into the refrigerator.

After around 5 minutes, we took the ice cube out of the refrigerator and we were surprised to see that the twine was inside the ice cube .

Then we did almost the same experiment but this after putting the twine inside we didn’t took it to the refrigerator, and this the ice cube was totally melt. 

Then we did the same experiment but instead of putting salt on top we put sugar, and put it inside the refrigerator, this time nothing happen as well.

Finally we did the experiment (the one with the sugar) but we didn’t put it in the refrigerator. 

 D° To conclude this experiment, we can say that the only time the ice melt around the twine was when we put salt on it and put it back into the refrigerator 

 E° We can conclude that ice only melted with salt, but with the help of a low temperature, the ice can be reformed around the salt, and yes this experiment help us answer our question.

Which one protect us the most of the sun ?

b)On a transparent paper, we had highlight bright colors : blue, green, yellow and pink. And on other transparent papers, we had put different sun creams : 

The first one Vichy with FPS 50, an other one Garnier with FPS 50 and the last one Nivea with FPS 30. 

Under the UV lamp, we had put the transparent paper with highlighter. Over it we put the different papers with sun creams. 

After we took off the papers with sun cream and we put between the UV lamp and the colored paper the different sun glasses, the Ray Ban one (sun glasses of quality) and the other one (cheap sun glasses).

c)

d)After this experiments, we saw different reactions.

First we found that the sun creams with FPS 30 reduce a little the colors of the highlighters

and the sun cream with FPS 50 reduce more the colors than the sun cream with FPS 30.

Secondly for the sunglasses, we saw that the two had approximately the same effects.

But we saw a little difference, the RayBan are quite better than the others. With the two sunglasses, we saw that the UV goes to the border of the paper, he is not completely protect.

e)This experiment gave us the answer at our question.

With this results, we have done a conclusion :

For the sun cream, we can see FPS 50 have the better protection. But FPS 30 have also a little protection for the skin.

And for the sunglasses, we see the sunglasses of quality have a quite better protection than the cheap ones but they don't protect totally the eyes from the sun because of the space between the eyes and the glasses. The sunglasses are not enough close to the eyes to catch all the sun rays.

It’s why the sunglasses don’t protect enough from the sun.

f)To improve our experiment, we can take a fabric or a mater which react like the skin, which have the same sensibility. The highlighter react as the UV but they don’t have the same reaction as skin.