Buthanol Graphs

Here we can see the table, the graph and the conclusion from the experiment of buthanol. To see the rest of the lab report go to previous pages (Wednesday, 19th February post).

Table showing how pressure in kPa varies with time in s.
Buthanol Graph

Time (s) (x)	Pressure (kPa) (y)
335.8	11.6
290	11.6
285	11.2
242.9	10.8
233.2	10.8
224.4	11.2
204.6	11.6
180.6	11.6
167.4	11.5
144.6	10.8
136.7	10.5
122.7	9.7
117.4	7.9
109.5	7.9
100	7.9
70	7.1
0	5.6

Graph showing how pressure in kPa varies with time in s.

Conclusion:According to the results of the table and the graph we can conlude that as time increases, the pressure of buthanol does too. At 0ºC, the pressure was of 5 kPa, after a determined time (increase of time) and with higher temperature (16ºC), the pressure increased to 7 kPa. As we increassed temperature and time passed by, the variation in temperrature continued until it reached 11.6 kPa. This is the maximum pressure of this substance. We continued increasing the temperature and time passed but the pressure started to decrease and then it increased again with 40ºC. As time passes the pressure of buthanol rises because as it is volatile, it goes from liquid to gaseous state, so particles spread and hit against walls more often, there was a slight decrease between second 150 and second 200, maybe due to a change in the temperature or human error. Observing the table and graph we can conclude that as time changes pressure does too. As time increases pressure increases. However, pressure reaches its maximum point in 11.6 kPA. It is a "barrier", because despite the fact that time continues to increase, pressure remains constant. Furthermore, it even decreases to 10.8 kPA, though after 40 seconds it increases again. 

SOLUTIONS LAB SESSION

NOTES FROM THE LAB:

mass and volume

electronic scale: number of figures after the coma

volume

Materials: volumetric flask, beaker, pipette, measuring cylinder

Volume of water: 10mL= 9.62g

C: Salt dissolves in water because of its chemical bonds.

PROCEDURE AND RESULTS

We took 10 mL of cyclohexane and 2.5 grams of sodium chloride. We poured them in the same dry measuring cylinder. The total volume was of 11.5 mL

The variation when we poured the NaCl was of 1.5 mL.

As it does not dissolve, we can work out the volume of the NaCl by measuring the change in volume of the mixture.

They didn’t dissolve so the mass was the same, so the volume will be the sum of both of them. The final volume was 11.5 mL. Volume of NaCl: 1.5 mL.

We see that NaCl doesn’t dissolve in hexane, but we will see that it does in water. Why? One of them (NaCl) is a polar molecule and the other one (hexane) is a non-polar molecule. Bonds.

“Matter cannot be created or destroyed, so mass is always conserved”. Our data agrees with this statement as the mass of hexane plus the mass of salt was the same as the mass of the solution:

Mass of hexane:

Mass of salt: 2.5 grams We sum them: ___

Final mass of the solution: ____

2. Is mass conserved when 2.5 g of salt is dissolved in water?

Weight a clean, dry 25mL measuring cylinder. 73. 68 grams

Take 10 mL of water with a pipette and pour it in the cylinder. Weigh it again, now with the water. 

What is the mass of the water? 10 mL of H2O weight 9.62 grams.

What should the mass of water be per gram? It should be 1 mL per gram but as it is not pure water we can observe that the mass is different.

Weigh 2.50 g of sodium chloride. Add it to the water and dissolve it.

Weigh the whole apparatus: 85.72 grams

Does the total mass equal the masses of the different parts?

Total mass: 85.72- 73.68= 12. 04 grams→ mass of the solution

mass of water: 9.62 grams, mass of salt: 2.5 grams. 9.62+2.5= 12.12

Is mass conserved? As we can see mass is conserved mostly, the 0.04 grams that varied may be due to human errors.

So mass is always conserved, but as we will see something different happens with volume.

What s the final volume of the solution?

3. Is volume “additive” (can we just add the individual volumes to get the final volume) when 2.5 g sodium chloride is dissolved in water? 

The volume of the mixture was smaller than the sum of both separately.

The answer is no, the volume of the water sums up to the volume of salt or sums up to the hexane is not the same as the total and final volume of the solution as in the final volume, salt is dissolved. This may have been because as the salt bonded with the water molecules, less space was occupied.

Demonstration:

What was the initial volume of water in part 2? 10 mL

What is the actual final volume of your sodium chloride solution? 11 mL. The final volume is different to the one we predicted, is less for the reason explained before. If 1 gram of NaCl is almost 1 mL of water (0.87 mL), the volume must be much more high if it was the sum of solute and solvent. The volume of salt should be 2.1 mL and the difference was of just 1 mL.

(11 mL , Vsolution, - 10mL ,Vwater, = 1 mL)

27/ January / 2014 

LAB REPORT ON CH3(CH2)3OH, BUTANOL

In this lab report, we observed the changes in the pressure of this substance where we were changing its temperature.

"Butanol (also butyl alcohol) refers to a four-carbon alcohol with a formula of CH3(CH2)3OH. There are four possible isomeric structures for butanol, from a straight-chain primary alcohol to a branched-chain tertiary alcohol. It is primarily used as a solvent, as an intermediate in chemical synthesis, and as a fuel. It is sometimes also called biobutanol when produced biologically". (Wikipedia, 2014)

The characteristics of butanol are:

(Responsiblebusiness.eu, 2014)

Structure of butanol:

(Commons.wikimedia.org, 2008)

We had butanol connected to the computer, to a program called logger pro.

Temperature (ºC)	Initial (kPa)	Final (kPa)
0ºC	5.00	5.00
16ºC	5.71	7.21
30ºC	11.18	11.25
40ºC	7.34	11.57

In 40ºC the water bath was bigger so we could put the whole shlenk tube in and that changed the results.

References:

Wikipedia. 2014. Butanol. [online] Available at: http://en.wikipedia.org/wiki/Butanol [Accessed: 19 Feb 2014].

Responsiblebusiness.eu. 2014. Biobutanol Processing - REBEL WP7: Bioenergy - REBEL Wiki. [online] Available at: http://www.responsiblebusiness.eu/display/rebwp7/Biobutanol+Processing [Accessed: 21 Feb 2014].

Bibliography: Commons.wikimedia.org. 2008. File:Butanol flat structure.png - Wikimedia Commons. [online] Available at: http://commons.wikimedia.org/wiki/File:Butanol_flat_structure.png [Accessed: 21 Feb 2014].

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.