As seen above by the graphs and data, an increase in molarity of NaCl solution results in a more negative percent change in mass. Therefore, there is a negative linear correlation between an increase in molarity and the mass of the potato; additionally, there is a strong correlation, as shown by the coefficient of determination (r2) of 0.965 in figure 4. For further evidence, the potato cubes that were soaked in the high molarity solution (0.5M and 0.4M) were much smaller and harder than prior to soaking, so the mass most likely decreased if the potato’s size also decreased. Comparatively, when the potato cubes were soaked in a low molarity solution (0.0M, 0.1M), the potato should become much larger and soggier, with a higher mass …show more content…
If these two values were removed, the overall trend of the % change in mass in different concentration solutions would be a negative linear relationship as predicted. These two values are further proved unuseful to determine the osmolarity of the potato because of the large spread of the error bar in 0.1M, where there is a huge range of values that were found. There is a large skew into the positive % change in mass area, which shows that some values for the 0.1M were obtained correctly, however the majority of the trials received contradictory data to the expectation of a positive % change in mass. Additionally, by looking at other studies that conducted similar experiments using potatoes, their results showed similar trends for % change in mass and increasing molarity. Therefore, if these two values are removed and a linear equation is used (figure 5), the x-intercept (where the % change in mass is zero) is the estimated value of the molarity where the solution is isotonic to the potato, around 0.229M. The osmolarity of the potato can then be deduced by multiplying the molarity by 2, as there are two particles (Na+ and Cl- in the solution for each compound of NaCl); thus, the osmolarity of the potato is 0.229 x 2 = 0.458 …show more content…
A consistent method was never disscused with the team members so sometimes the potatoes were wrapped in a towel and lightly squeezed, and other times they were rolled on the towel. The two methods of drying are very different: one is more rough and takes more water out of the potato, while the other method uses wet parts of the towel to dry the potatos. To eliminate this inconsistency, all the lab members should agree to one method of drying, specifically a method that is the most gentle (such as rolling the wet potato on top of the towel), and drying each potato on a dry part of the