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Partners: Jonah Barnett, Clell Carnes III, Josh Moore, Austin Walden

Date: 11-5-15
Safety: Do not get sucrose solution
Procedure: See Lab Handout
Materials: See Lab Handout
Diffusion pre-lab:

1B: Dialysis tubing bags

-Independent: Molar concentration of solution
-Dependent: change in mass of the bag
-constants: amount of solution, amount of starch in bags
Data table:


1. The higher molar concentration in the beakers caused a
larger concentration gradient into the dialysis bags causing its
mass to increase.
2. If all of the bags were placed into a 0.4 m sucrose solution
the 0.0 m and 0.2 m sucrose solutions would decrease in size to
try to fix the concentration gradient, the 0.6 m 0.8 m 1.0 m
sucrose solution would increase in size to fix the concentration

gradient, and the 0.4 m sucrose solution would remain the same
because it is the same amount of solution in each bag.
3. All the initial values were different, so to get a more
accurate representation of how much they increased, a
percentage was used.
4. 20grams to 18g= -2g change, -2/20= -10% change
5. Hypertonic
Conclusion: After the lab, we determined that the molar
concentrations of the solutions go as follows: Red is .4M, Orange is
0M, Yellow is .8M, Green is .6M, Blue is .2M, and Purple is 1.0M. We
determined the concentrations by Water and solute potential of the
solutions. The one with more solute concentration didn't have as
much water potential which meant the mass of the bags changed less
with more. In the 0m concentration, the solution outside of the bag
had a lower water potential than insider which meant that the
concentration gradient made water flow out of the bag, causing a
decrease in mass inside the bag. The rest of the concentrations had a
higher water potential and lower water potential than the bag, which
caused the concentration gradient to flip and make water flow into
the bags because of the low water potential. Our graph reflects how
the lower concentrated solutions increased less, and even decreased,
compared to the higher concentrations. Our hypothesis was correct
according to our findings. The more sugar in the bag, means a larger
solute potential and a smaller water potential, meaning that the mass
increases more due to the concentration gradient. Our results may
have been slightly altered by the time the bags were left out of the
water, which may have led to some evaporation of the water, altering
the water potential, and the concentration gradient. This could be
solved by having more people tying bags so that the time out of
solution is minimal and decreases the chance of the evaporation.
1C: Potato Cores
-Independent: Molar Concentration of solution

-Dependent: change in mass

-constants: Amount of solution
Data table:


1D: Calculations and experimental data

Solute/water potential:

1. It would decrease because there is less water to move

inside of the potato.
2. The cell is hypertonic in solute concentration. It will gain
water from its environment via the concentration gradient.
3. There is is no pressure potential because it is open air.
4. Dialysis bag
5. Into because it has less wager potential, so water needs to
move into the bag to reach equilibrium.





9. Adding solute to a solution adds to its solute potential. This

is because there is more solute available to move around, and
less water per area.
Distilled H2O
B. Distilled H2O
C. It would swell because of the water following the
concentration gradient into Blood Cell
11. Grass near roads die because of the restriction of osmosis.
The salt concentration increases inside the plant, which lowers
the concentration gradient of the cells surrounding, which
makes it harder for the cells vacuoles to get the water to
support the plant, leaving it withered, and eventually dead.