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 Big 1Small 1Big 2Small2 Before Diameter 1.41.01.41.0 Length 3.5 Concentration % 0022 Weight 4.12.54 NaCl (grams) 0011 After Weight 4.32.54.42.7 Diameter 1.30.91.30.9 Length 3.43.53.4

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