Osmotic Rate of Size and Concentration

1. Osmotic Rate of Size and Concentration By: Cody Sloan Trenten Fenster

2. Purpose • To see the affect that size has on osmotic rates • To observe how concentrations of the solute affect osmotic rate

3. Procedure • Cut two different size cores from a potato, two of each • Weight and measure to make each potato core the same weight and length • Create two different solutions: Distilled water, and 2% salt solution • Put one small core and one big core in the distilled water and leave for 15min • Do the same with the other cores in the 2% solution

4. Hypothesis • If the smaller piece has a faster osmotic rate it is because the molecules don’t have to move as much. If the bigger piece has a faster osmotic rate its because it has a larger surface area. • If the higher concentrated solution has a faster osmotic rate then it is because there are more particles to go out of the cell.

5. Data

6. Analysis Mass percent change: Big 1: 4.65% Small 1: 0% Big 2: 9.09% Small 2: 7.41%

7. Conclusion • All samples gained weight except for Small 1 which didn’t gain or lose weight • This means that the salt ion concentration inside of the cell is greater than 2% • Also, the bigger samples gained more weight overall (proven by the % mass change) • This proves the fact that the larger sample gains more water because there is a bigger surface area for the water to get into the cell through

8. Errors and Improvements • An error that could have occurred is that we could have left the potato cores in for different amounts of time • Another thing that could have happened is that the cores could have been slightly different shapes and weighs • A final error that could have occurred is that we could have measured an incorrect amount of salt for the concentrated solution