LAB VISIT by María Gallego García and Coral Conde Velasco 10B


Materials:
Method:
We used a pressure-volume meter and observed it, we made our own hypothesis about how it worked.
Then, we wrote all the results, made some graphs and tables and wrote down our own conclusions. It has been a nice and curious experiment!

pressure-volume meter

As we can see, there is a tube where we can see the volume of air (O2 and other gases) that we change by moving a roller handle.

There is also a thermometer, showing the temperature and a device that measures the pressure.

The lower the volume, the higher the pressure. This is because the same amount of air is compressed in a determined volume. We can change the volume (so it is the independent variable), and when volume changes pressure does too (so it is the ). In higher pressure, the same amount of air will be compressed in a lower space or volume. They have an inversely proportional relationship.

Afterwards, we turned the handle so that the volume was at its maximum point: 60 mL. After this, we closed it (turning the red thing you can see in the picture). So there we had all the air we were going to have. We wrote down the volume (which was 60 mL) and the pressure. We started to turn the roller handle, so the volume in which the air was smaller and smaller each time. We wrote this pressure in certain values for the volume in mL (60, 55, 50, 45, 40, 35, 30, 25 and 20).
Then, we wrote all the results, made some graphs and tables and wrote down our own conclusions. It has been a nice and curious experiment!
These results are shown in the next post.

Lab visit results

Here are the results of the experiment we did in the last lab visit: (the previous post)


Relation between the volume and the pressure:

V (mL)	P (hPa)
60	1(atm pres.)
55	100
50	200
45	300
40	500
35	750
30	1000
25	1500
20	2100

As it is an inversely proportional relationship, when we do the inverse of the volume, the function is proportional, as we can see  in the second graph

1/

V (mL)

P (hPa)

0,01666667 (1/60mL)	1
0,01818182 (1/55mL)	100
0,02 (1/50mL)	200
0,02222222 (1/45mL)	300
0,025 (1/40mL)	500
0,02857143 (1/35mL)	750
0,03333333 (1/30mL)	1000
0,04 (1/25mL)	1500
0,05 (1/20mL)	2100

LAB VISIT Nº1

This is our first visit to the physics lab.

Here is a photo of the different materials we used.

We used a schlenk tube, stopcock, some protective glasses for our eyes, vaseline and an elastic rubber. 

We worked in pairs so we could help each others.

 

1 BY 1 STEPS.

1.- We put our protective glasses on.
2.-We applied some vaseline to the stopcock being carefull that no vaseline gets in the whole ofthe stopcock.
3.- We place the stopcock again into the schlenk tube.
4.- We twist it so the stopcock isn't parallel with the schlenk tube.
5.- We make sure that the stopcock doesn't move out from the schlenk tube with the elastic rubber by following these steps:

• We twist the elastic rubber in two.
• We started from the bottom.
• We cross it trough the top.
• We twist it and cross it from the top again.
• We twist it again, and cross it troughthe bottom part.

6.-Then we take off the the elastic rubber and take off the stopcock and we clean the vaseline out from it.

7.- We put the materiasl again in their places.

*Here is a video for you*

Other two members of our group want to show you how to work with this:

http://www.youtube.com/watch?v=qxu5W4bk4I8
http://www.youtube.com/watch?v=KJfc5_YFFb0

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Who we are? We are students from sfpaula school year 10B: Manuel Saldaña, Coral Conde, María Gallego and Isabel Silva.