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# Osmosis Lab Report Essay

To what extent does varying the Sodium Chloride concentration impact the mass change of Solanum tuberosum cubes? Katie Hynek 12/11/15 Personal Engagement: Every Thanksgiving my aunt and grandma switch off making mashed potatoes and every year they use the same recipe. This year it was my aunt’s turn and when we went to eat the mashed potatoes they were super salty. After thanksgiving dinner that year I became interested in figuring out how the using the same recipes the outcome could be so different.

Background Information: Osmosis is the of a solvent across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration. The water being the solvent can move across the membrane but the salt cannot Research Question: To what extent does varying the Sodium chloride concentration impact the mass changes of Solanum tuberosum cubes? Hypothesis: If Sodium chloride affects the mass of Solanum tuberosum then the mass should go up ten percent every time you increase the salt concentration by 0.2.

Variables: Variables How variables are measured Independent Variable Sodium chloride Electronic balance (0.00, 0.20,0.40,0.60,0.80 (+0.1) grams) Dependent Variable Mass of Solanum tuberosum and electronic balance Controlled Variable Size of the Potato Electronic balance (3.00 grams) Controlled Variable Time spent in the solution Leave in the solution for 5 days Controlled Variable Volume of water Measure the distilled water with a graduated cylinder (100 mL . 5mL) Controlled Variable Room temperature Keep the beakers in the same place on touched that you measured temperature (21.1C +1.2)

Materials: 25 Russet potato cores Tweezers Tongs Scalpel Table Salt (0.2,0.4,0.6,0.8 grams) Electronic balance (+0.10 g) Distilled Water (100 mL) 5 glass beakers Marking Tape Ruler (+ 0.05 cm) Stirring rod Potato corer (9 diameters) Graduated cylinder ( +0.50 mL) Filter paper Sketch of lab setup: Procedure: Label beaker one’s tape 0.0 grams of salt Label beaker two’s tape 0.2 grams of salt Label beaker three’s tape 0.4 grams of salt Label beaker four’s tape 0.6 grams of salt Label beaker five’s tape 0.8 grams of salt Utilize potato corer to obtain 25 cores of five or six potatoes Place each core on an electronic balance to determine the initial mass.

Shave off pieces of potato until each core has a mass of 3.0 grams Fill each beaker with 100mL of distilled water at room temperature Measure out 0.2, 0.4, 0.6, 0.8 grams of salt Leave beaker one alone, place 0.2 grams of salt in the second beaker, place 0.4 grams of salt in the third beaker, place 0.6 in the fourth beaker, and place 0.8 in the fifth beaker Use the stirring rod to stir the distilled water and the salt until you can’t see the crystals anymore Place 5 potato cores in each beaker of salt water solution Leave the potato cores in the solution for five days Beginning with the beaker of 0.0 g pull one potato core out of the solution and utilization of the electronic balance, determine the mass of each.

Record all data in the raw data table Repeat for all five potato cores and all five beakers Safety and Ethical Concerns: Exercise caution when utilizing a sharp instrument such as a scalpel. Analysis: Raw Data Qualitative Observations 0.0 grams The water turned a dark brown color and the potatoes decomposed 0.2 grams The water was a brown color and the potatoes were sticky and hard to grab with the tweezers 0.4 grams The water was a murky brown and the potatoes were hard to grab and looked like they were covered in a coat of mucus 0.6 grams The water was murky and the potatoes were semi brown 0.8 grams Water was semi cleat and the potatoes were in tact Anova Test

Data processing: Anova test Ho= The Sodium chloride concentrations in the distilled water is independent H1= The mass of Solanum tuberosum after soaking in the Sodium chloride solution is dependent I created an Anova test to determine if there was any significant changes between three or more groups being tested. In my case there was significant changes. There was significant changes between the different concentrations. Average To calculate average first you have to add up all the number is the 0.0 grams column. After you have the 0.0 grams added up you need to divide by how many numbers in the column.

An example is in column 0.0 grams, 4.2+3.1+4.0+3.2+4.3= 18.8. Once you have the total from the column you divide by how many numbers you added together, 18.8/5=3.76. The average is 3.76 for 0.0 grams. You repeat the steps for the rest of the columns. Standard Deviation Formula: Average of all 5 concentrations at each level X-X The average of all groups added together minus the average of all 5 concentrations at each level X-X2 The answer that you got from the second to the power of 2 3.75-3.75 Processed data presentations: Evaluation: Conclusion and Evaluation Based on my data of salt concentrations in the solution doesn’t impact the change in mass directly. The potatoes were kept at a constant mass of 3.0 grams.

After the five days the potatoes were remeasured and all the potatoes masses varied in mass amounts. Minimal amounts of changes in mass happen along with some amounts increased greatly. Some of these increases were in the same solutions with the same salt concentrations. After I analyzed my data the hypothesis must be rejected. My hypothesis is, If Sodium chloride affects the mass of Solanum tuberosum then the mass should go up because Sodium chloride would make osmosis reaction absorb more of the salt concentration.

At the increase would be one to five grams at the most. Strengths and Weaknesses During my experiment I came across many limitations and many strengths. One of my strengths was collecting data. Collecting data was one of my strengths because I collected data the same at the beginning and at the end of the experiment. Another strength is performing the experiment. This is considered a strength because I made sure that everything was the same measurement and the same amount of water. Everything was done to exact measurement. One more strength to my experiment is the set up. The setup was a strengths because I set up my experiment will a sure thing that I would have a 5 by 5 matrix.

I also made sure that the potatoes were in a straight line in the beaker and that there was five to a beaker. Limitations/ Weaknesses Proposed Solution Using an electronic balance that only measures +0.1 Using an analytical balance that measures +0.001 or +0.0001 Only going up by 0.2 every time Go up by a greater increase like 1.0 Stirring the salt to the crystals dissolve Boil the salt till it dissolves on its own Massing the potatoes after five days Mass the potatoes every hour for five hours Improvement and Extensions One improvement would be a lesser time frame.

A lesser time frame would stop the potatoes from rotting which would give out correct measurements. Another improvement is to add bigger salt concentrations that way if the rest of the experiment go as planned there will be a bigger change. Further Research Questions Does the temperature of distilled water impact the rate of osmosis on Solanum tuberosum? Does the bigger cores taken from Solanum tuberosum change how much water is lost during osmosis?

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