Name: __________________________________
AP Biology
Mystery Solutions Lab
1. Make 6 potato cores with a borer. Make sure potato cores are approximately the same size and length.
2. Weigh each core using a digital balance and measure the length of each core. Record your data in your
laboratory notebook.
3. Place one or more potato cores in each of the mystery sucrose solutions.
4. Wait 30 minutes.
6. After 30 minutes, re-weigh the cores, and calculate the changes in their weight. Calculate the changes
in their length and mass. Record your data in your laboratory notebook.
Solution 1
Solution 2
Solution 3
Solution 4
Solution 5
Potato Core Potato Core Potato Core Potato Core Potato Core
Solution 6
Potato Core
Initial Mass
Final Mass
Initial Length
Final Length
What is the concentration of each of the following solutions?
Solution 1: ______________
Solution 2: _______________
Solution 3: _____________
Solution 4: _____________
Solution 5: _______________
Solution 6: _____________
Analysis
1.
Which solution was the most hypertonic to the potato cores? Explain how you determined this.
2. Which solution was the most hypotonic to the potato cores? Explain how you determined this.
3. Determine the water potential for each beaker. Use the following equation:
Water Potential = Pressure Potential + Solute Potential
The solute potential (ψS) = – iCRT, where i is the ionization constant, C is the molar
concentration, R is the pressure constant (R = 0.0831 liter bars/mole-K), and T is the temperature
in K (273 + °C).