Essay, Research Paper: Potatoe Piece Lab

Data:

First Round Check Mass of Piece 1 After 10 minutes Mass of Piece 1 After 20 Minutes Mass of Piece 1 After 30 Minutes Mass of Piece 1 After 40 Minutes
+60? Water 2.1 2.5 2.5 2.0

10? Water 2.1 2.4 2.2 2.1
Sugar Solute 2.1 2.2 2.3 2.2
Salt Solute 2.1 2.0 2.4 2.1
Room Temp. Water (C.) 2.1 1.9 2.2 2.3

First Round Check Mass of Piece 2 After 10 minutes Mass of Piece 2 After 20 Minutes Mass of Piece 2 After 30 Minutes Mass of Piece 2 After 40 Minutes Average of Mass of Piece 1 & 2 (g.)
+60? Water 2.1 2.6 2.1 2.5 2.3

10? Water 2.1 2.3 2.1 2.2 2.19
Sugar Solute 2.1 2.1 2.3 2.1 2.18
Salt Solute 2.1 1.9 2.2 1.8 2.07
Room Temp. Water (C.) 2.1 2.2 2.5 2.3 2.21

Mass of Piece 1 After 10 minutes Mass of Piece 1 After 20 Minutes Mass of Piece 1 After 30 Minutes Mass of Piece 1 After 40 Minutes
Mix of Sucrose Solution and 60? Water 2.1 2.0 2.3 2.5

Mass of Piece 2 After 10 minutes Mass of Piece 2 After 20 Minutes Mass of Piece 2 After 30 Minutes Mass of Piece 2 After 40 Minutes
Mix of Sucrose Solution and 60? Water 2.1 2.3 2.2 2.4
Average Mass of Piece 1 & 2 2.1 2.15 2.25 2.45

Diagram
OSMOSIS POTATO PIECE LAB
Michael Zohar
November 5, 1998

Problem: Which combination of variables will increase the mass of the potato piece the fastest and which variable is most influential to the mass of the potato piece.

Variables: I will test several variables separately including warm temperature distilled water, cold temperature distilled water, 15 g. sugar/100 ml. distilled water sugar solution, 15 g. salt/100 ml. distilled water salt solution, and room temperature distilled water as a constant. The volume of the liquid will be kept at a constant of 100 ml. as well as the room pressure and temperature. I will be able to see how much each variable affected the mass of a 1.2 g. spherical potato piece by changing only one variable at a time and keeping all others constant. After I see which individual variables from the temperature category and the solute category affected the mass of the potato piece the most I will mix the two variables seeing which variable has the most influence on the potato piece by comparing it in a graph.

Description: The way I will test these variables is by starting with a 1.2 g. constant mass and surface area of a potato piece. Then I will submerge the potato piece completely into the 100 ml. of liquid, two pieces per beaker for forty minutes checking the weight in 10 minute increments, after I dry the piece off with a paper towel. I will put a dot on every other potato piece in each beaker to get two results being able to average them out in the end. Then I will put the pieces back in the beakers and leave them undisturbed until the next weighing until weighing is finished. I will then compare my results using several graphs and conclude and prove which combination turns the piece turgid the fastest by combining the two variables and putting two pieces submerged for 40 minutes checking in more ten minute increments.

Prediction: I predict that the warm water and the salt solution will turn the potato piece turgid the fastest for a few reasons. One the water molecules in the warm water are moving faster than the others making changes happen sooner. Another reason is that since the concentration of salt molecules in the environment outside the potato cells is lower than that in the cell, the solution is hypotonic relative to its environment allowing water to move into the potato cells. Sugar solute however would most likely be hypertonic because there would be more sugar concentration inside the potato cells than outside creating plasmolysis eventually.
Safety: All standard safety measures are to be taken while using the hot plate such as keeping it away from clumsy places and flammable objects. *Be sure to use metal gauss between the hot plate to avoid the risk of the heat not transferring and the bottom of the beaker falling out.

Apparatus: Five beakers, One potato, One bore, One triple beam balance, 15 grams of sugar, 15 grams of salt, stirring rod, paper towels, hot plate with metal gauss, insulated thongs, tweezers.

Limitations: One of the main limitations was to what decimal place the weighings could be accurate. Ideally an electronic scale could have been used in order to be precise up to 0.01 g. Another clear limitation is the constant of the surface area and consistency of the potato. Ideally surface area could be exact using mathematics and keen measurement however this is not realistic in this case. Yet another limitation is the extreme challenge of keeping a beaker of water at a constant heat on a hot plate. To do this you must manually turn the knob on and off checking periodically the temperature with a thermometer. Ideally a device to keep the temperature at a constant automatically lowering and raising temperature when necessary. Another thing is the time limitation given here. With this experiment time doesn't permit days or maybe weeks of study as well as many different 'checks' in order to get the ideal information and data.
Method:
1. Setup a clear area with five beakers filling all of them with 100 ml. of distilled water.
2. Weigh out 15 g. of salt and sugar dissolving them each into a separate beaker with a stirring rod.
3. Take one of the beakers with distilled water outside to a cold area where it the water temp. can reach ten C.
4. Take the other beaker containing distilled water and place it on the hot plate on top of the metal gauss. Put the hot plate to the 2nd setting and leave for 10 minutes.
5. Cut up ten pieces of potato using a bore getting them as similar in surface area and mass as possible. Weigh these pieces individually on a triple-beam balance trimming pieces when necessary.
6. Using a permanent marker place a dot on every other piece representing piece 2.
7. Place two pieces per beaker into all beakers simultaneously, on with a dot and one with none noting when you placed them in.
8. Remove the pieces after ten minutes with a pair of tweezers and dry with a paper towel. Weigh these pieces individually and record them in the data table making sure to differentiate from the pieces with dots which go under "Piece 2."
9. Continue on until the table is filled out.
10. After assessing which two variables out of temp. and solute increased mass the mass combine these two variable and do as stated above until the data table is completely filled out.

Conclusion: From my results in the experiment I could not accurately answer my problem however I can further hypothesize that with some modifications and a better scientific method I would find a conclusion something along the lines of what was stated in the prediction. The main problem that threw off my data I believe is the limitation of the triple beam balance to read data beyond 0.1 g. Two solutions can be found for this problem, either use an electronic balance or increase the proportions of the whole experiment. With my limited data however I have seen that my prediction that warm water would increase the mass of the potato piece faster because of the increased speed in hot water molecules which would effect the piece much faster than the cold water. My prediction however that the salt solute would increase the mass of the potato piece faster was wrong, I can conclude nothing from my data whether my prediction is right or wrong. However it seems that my hypothesis that there was a higher sugar concentration inside the potato than outside while in the sugar solute was wrong. Perhaps with different potatoes such as sweet potatoes or different species the sugar concentration is higher inside. As with my graphs; I cannot make exact since of them and they seem to truly show what chaos has come from my data .

Modifications and Final Notes: After having done this experiment I have learned much about doing experiments and using the scientific method. If I could do it all again however I would change countless things. First of all I would make sure that everything in my experiment was realistic and that performing the tests were more practical. I found it very hard when it came time to collect the data to be as accurate as I'd have liked to have been. I gave myself only ten minute increments making it hard to make the measurements of all ten pieces within one or two minutes. I needed to rush through what should have been done thoroughly and precisely and I'm sure that had I been more exact I would have yielded much better results. I also think the time period should have been extended to at least one day of my weighing with longer increments between each one. With a longer time period I could have effectively reached the turgid level of the potato pieces. And with the graphs, I don't know what went wrong exactly but they seem to represent how off my results were in the best way. Their criss-crossing lines effectively show the margin of error however in this type of experiment. Another thing was the extremely small increments with which I was dealing with. With everything enlarged I could have seen a change much easier and would have been able to make very clear easy to read results on the graphs and data tables. With my scientific method perfected, I could have surely yielded superb results for an excellent and highly complex, however rewarding if done correctly; disastrous if done incorrectly, lab experiment.