Equipment
10 Test tubes
Large Potato
4mm Cork borer
Scalpel
Weighing scales
15mm Ruler
Sodium Chloride Solution
Measuring cylinder
Sticky labels
Test tube rack
Paper towels
Safety
To ensure that my experiment is safe I will be sure to wear safely glasses at all times. Take care when using sharp implements like the scalpel and be sure not to spill the Sodium Chloride solution.
Fair test
To ensure that my experiment is a fair test I will follow my method exactly at all times and be sure to use the same mm cork borer and cut all the potato chips to same length.
Method
First of all I will collect all of the equipment needed for the investigation and set it up accordingly.
Using a 4mm Cork borer I will cut 5 equal potato chips and using a scalpel cut each of these chips to 30mm long. I will then weigh each individual chip and record its Initial mass and length before labeling each test tube and placing the correct chip in them. Each test tube should be labeled with the Concentration in molar of Sodium Chloride solution used and the groups initials. Using a measuring cylinder measure 20ml of distilled water and pour into the test tube marked 0 molar.
Prepare the Sodium Chloride solutions according to the table below.
Into each previously marked test tube pour the correct solution and then place one chip in each test tube.
Leave the test tube for twenty minutes.
Remove the chips from the test tubes and dry with a paper towel. Re-measure the length and mass and record in a table.
Repeat the experiment to obtain a second set of results.
Results
Set 1
Set 2
Average results
Conclusion
In conclusion to the investigation I found out that the lower the concentration of Sodium Chloride solution, the higher the final mass and length was and the higher the concentration of Sodium Chloride solution, the lower the final mass and length was.
Also, at a concentration of 0 and 1 molar, the change in mass and length was greater than 0.125, 0.25 and 0.5 molar which only slightly different.
My prediction was therefore correct.
Evaluation
My investigation in general worked very well. We obtained accurate results that we needed to draw a firm conclusion and all went according to the initial plan. There were no anomalous results in this investigation.
I think that our method did work but it would have helped during the experiment if it was more detailed. I would think about rearranging some of the points and maybe doing some parts of the experiment differently or in a different order as we did seem a little unorganized throughout the experiment. If I was to do the experiment again I would label all of the test tubes before starting the experiment to avoid farther confusion.
I do think we obtained enough results to draw a firm conclusion and the averages proved to produce an accurate graph for both the length and mass of the potato chip.
I think our only concern would be that the length of the chip may not be perfectly accurate each time because of the measuring device used.
Our results were all repeatable and followed the line of best fit. There were no anomalous results so I would therefore conclude that our experiment was a success and our results were reliable.